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Roman-Campos D, Marin-Neto JA, Santos-Miranda A, Kong N, D’Avila A, Rassi A. Arrhythmogenic Manifestations of Chagas Disease: Perspectives From the Bench to Bedside. Circ Res 2024; 134:1379-1397. [PMID: 38723031 PMCID: PMC11081486 DOI: 10.1161/circresaha.124.324507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/13/2024]
Abstract
Chagas cardiomyopathy caused by infection with the intracellular parasite Trypanosoma cruzi is the most common and severe expression of human Chagas disease. Heart failure, systemic and pulmonary thromboembolism, arrhythmia, and sudden cardiac death are the principal clinical manifestations of Chagas cardiomyopathy. Ventricular arrhythmias contribute significantly to morbidity and mortality and are the major cause of sudden cardiac death. Significant gaps still exist in the understanding of the pathogenesis mechanisms underlying the arrhythmogenic manifestations of Chagas cardiomyopathy. This article will review the data from experimental studies and translate those findings to draw hypotheses about clinical observations. Human- and animal-based studies at molecular, cellular, tissue, and organ levels suggest 5 main pillars of remodeling caused by the interaction of host and parasite: immunologic, electrical, autonomic, microvascular, and contractile. Integrating these 5 remodeling processes will bring insights into the current knowledge in the field, highlighting some key features for future management of this arrhythmogenic disease.
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Affiliation(s)
- Danilo Roman-Campos
- Departamento de Biofísica, Escola Paulsita de Medicina, Laboratório de Cardiobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil (D.R-C)
| | - José Antonio Marin-Neto
- Unidade de Hemodinâmica e Cardiologia Intervencionista, Escola de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil (J.A.M-N.)
| | - Artur Santos-Miranda
- Departamento de Fisiologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil (A.S.-M)
| | - Nathan Kong
- Departamento de Biofísica, Escola Paulsita de Medicina, Laboratório de Cardiobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil (D.R-C)
- Unidade de Hemodinâmica e Cardiologia Intervencionista, Escola de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil (J.A.M-N.)
- Departamento de Fisiologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil (A.S.-M)
- Hospital do Coração Anis Rassi, Goiânia, GO, Brazil (A.R.J.)
| | - André D’Avila
- Departamento de Biofísica, Escola Paulsita de Medicina, Laboratório de Cardiobiologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil (D.R-C)
- Unidade de Hemodinâmica e Cardiologia Intervencionista, Escola de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil (J.A.M-N.)
- Departamento de Fisiologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil (A.S.-M)
- Hospital do Coração Anis Rassi, Goiânia, GO, Brazil (A.R.J.)
| | - Anis Rassi
- Hospital do Coração Anis Rassi, Goiânia, GO, Brazil (A.R.J.)
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Burg S, Levi O, Elyagon S, Shapiro S, Murninkas M, Etzion S, Gradwohl G, Makarovsky D, Lichtenstein A, Gordon Y, Attali B, Etzion Y. The SK4 channel allosteric blocker, BA6b9, reduces atrial fibrillation substrate in rats with reduced ejection fraction. PNAS NEXUS 2024; 3:pgae192. [PMID: 38783894 PMCID: PMC11114471 DOI: 10.1093/pnasnexus/pgae192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Atrial fibrillation (AF), the most common cardiac arrhythmia, is strongly associated with several comorbidities including heart failure (HF). AF in general, and specifically in the context of HF, is progressive in nature and associated with poor clinical outcomes. Current therapies for AF are limited in number and efficacy and do not target the underlying causes of atrial remodeling such as inflammation or fibrosis. We previously identified the calcium-activated SK4 K+ channels, which are preferentially expressed in the atria relative to the ventricles in both rat and human hearts, as attractive druggable target for AF treatment. Here, we examined the ability of BA6b9, a novel allosteric inhibitor of SK4 channels that targets the specific calmodulin-PIP2 binding domain, to alter AF susceptibility and atrial remodeling in a systolic HF rat postmyocardial infarction (post-MI) model. Daily BA6b9 injection (20 mg/kg/day) for 3 weeks starting 1-week post-MI prolonged the atrial effective refractory period, reduced AF induction and duration, and dramatically prevented atrial structural remodeling. In the post-MI left atrium (LA), pronounced upregulation of the SK4 K+ channel was observed, with corresponding increases in collagen deposition, α-SMA levels, and NLRP3 inflammasome expression. Strikingly, BA6b9 treatment reversed these changes while also significantly reducing the lateralization of the atrial connexin Cx43 in the LA of post-MI rats. Our findings indicate that the blockade of SK4 K+ channels using BA6b9 not only favors rhythm control but also remarkably reduces atrial structural remodeling, a property that is highly desirable for novel AF therapies, particularly in patients with comorbid HF.
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Affiliation(s)
- Shira Burg
- Department of Physiology & Pharmacology, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Or Levi
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Sigal Elyagon
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Shir Shapiro
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Michael Murninkas
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Sharon Etzion
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Gideon Gradwohl
- Medical Engineering Unit, The Jerusalem College of Technology, Jerusalem 9116001, Israel
| | - Daria Makarovsky
- Inter-Departmental Core Facility, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Alexandra Lichtenstein
- Inter-Departmental Core Facility, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yaara Gordon
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Bernard Attali
- Department of Physiology & Pharmacology, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yoram Etzion
- Cardiac Arrhythmia Research Laboratory, Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
- Regenerative Medicine & Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
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Shi R, Reichardt M, Fiegle DJ, Küpfer LK, Czajka T, Sun Z, Salditt T, Dendorfer A, Seidel T, Bruegmann T. Contractility measurements for cardiotoxicity screening with ventricular myocardial slices of pigs. Cardiovasc Res 2023; 119:2469-2481. [PMID: 37934066 PMCID: PMC10651213 DOI: 10.1093/cvr/cvad141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 05/22/2023] [Accepted: 07/10/2023] [Indexed: 11/08/2023] Open
Abstract
AIMS Cardiotoxicity is one major reason why drugs do not enter or are withdrawn from the market. Thus, approaches are required to predict cardiotoxicity with high specificity and sensitivity. Ideally, such methods should be performed within intact cardiac tissue with high relevance for humans and detect acute and chronic side effects on electrophysiological behaviour, contractility, and tissue structure in an unbiased manner. Herein, we evaluate healthy pig myocardial slices and biomimetic cultivation setups (BMCS) as a new cardiotoxicity screening approach. METHODS AND RESULTS Pig left ventricular samples were cut into slices and spanned into BMCS with continuous electrical pacing and online force recording. Automated stimulation protocols were established to determine the force-frequency relationship (FFR), frequency dependence of contraction duration, effective refractory period (ERP), and pacing threshold. Slices generated 1.3 ± 0.14 mN/mm2 force at 0.5 Hz electrical pacing and showed a positive FFR and a shortening of contraction duration with increasing pacing rates. Approximately 62% of slices were able to contract for at least 6 days while showing stable ERP, contraction duration-frequency relationship, and preserved cardiac structure confirmed by confocal imaging and X-ray diffraction analysis. We used specific blockers of the most important cardiac ion channels to determine which analysis parameters are influenced. To validate our approach, we tested five drug candidates selected from the Comprehensive in vitro Proarrhythmia Assay list as well as acetylsalicylic acid and DMSO as controls in a blinded manner in three independent laboratories. We were able to detect all arrhythmic drugs and their respective mode of action on cardiac tissue including inhibition of Na+, Ca2+, and hERG channels as well as Na+/Ca2+ exchanger. CONCLUSION We systematically evaluate this approach for cardiotoxicity screening, which is of high relevance for humans and can be upscaled to medium-throughput screening. Thus, our approach will improve the predictive value and efficiency of preclinical cardiotoxicity screening.
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Affiliation(s)
- Runzhu Shi
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- International Research Training Group 1816, University Medical Center Göttingen, Göttingen, Germany
| | - Marius Reichardt
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
| | - Dominik J Fiegle
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Linda K Küpfer
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Titus Czajka
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
| | - Zhengwu Sun
- Walter-Brendel-Centre of Experimental Medicine, Hospital of the University Munich, Munich, Germany
| | - Tim Salditt
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen, Germany
| | - Andreas Dendorfer
- Walter-Brendel-Centre of Experimental Medicine, Hospital of the University Munich, Munich, Germany
- German Centre of Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany
| | - Thomas Seidel
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Tobias Bruegmann
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner site Göttingen, Göttingen, Germany
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Alvarez JAE, Jafri MS, Ullah A. Local Control Model of a Human Ventricular Myocyte: An Exploration of Frequency-Dependent Changes and Calcium Sparks. Biomolecules 2023; 13:1259. [PMID: 37627324 PMCID: PMC10452762 DOI: 10.3390/biom13081259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/07/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Calcium (Ca2+) sparks are the elementary events of excitation-contraction coupling, yet they are not explicitly represented in human ventricular myocyte models. A stochastic ventricular cardiomyocyte human model that adapts to intracellular Ca2+ ([Ca2+]i) dynamics, spark regulation, and frequency-dependent changes in the form of locally controlled Ca2+ release was developed. The 20,000 CRUs in this model are composed of 9 individual LCCs and 49 RyRs that function as couplons. The simulated action potential duration at 1 Hz steady-state pacing is ~0.280 s similar to human ventricular cell recordings. Rate-dependence experiments reveal that APD shortening mechanisms are largely contributed by the L-type calcium channel inactivation, RyR open fraction, and [Ca2+]myo concentrations. The dynamic slow-rapid-slow pacing protocol shows that RyR open probability during high pacing frequency (2.5 Hz) switches to an adapted "nonconducting" form of Ca2+-dependent transition state. The predicted force was also observed to be increased in high pacing, but the SR Ca2+ fractional release was lower due to the smaller difference between diastolic and systolic [Ca2+]SR. Restitution analysis through the S1S2 protocol and increased LCC Ca2+-dependent activation rate show that the duration of LCC opening helps modulate its effects on the APD restitution at different diastolic intervals. Ultimately, a longer duration of calcium sparks was observed in relation to the SR Ca2+ loading at high pacing rates. Overall, this study demonstrates the spontaneous Ca2+ release events and ion channel responses throughout various stimuli.
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Affiliation(s)
| | - M. Saleet Jafri
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Aman Ullah
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA;
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van Weperen VYH, Ripplinger CM, Vaseghi M. Autonomic control of ventricular function in health and disease: current state of the art. Clin Auton Res 2023; 33:491-517. [PMID: 37166736 PMCID: PMC10173946 DOI: 10.1007/s10286-023-00948-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/20/2023] [Indexed: 05/12/2023]
Abstract
PURPOSE Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure. METHODS Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized. RESULTS A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain. CONCLUSIONS Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.
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Affiliation(s)
- Valerie Y H van Weperen
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA
| | | | - Marmar Vaseghi
- Division of Cardiology, Department of Medicine, UCLA Cardiac Arrythmia Center, University of California, 100 Medical Plaza, Suite 660, Los Angeles, CA, 90095, USA.
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6
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Cserne Szappanos H, Viola HM, Ito DW, Lim S, Mangala M, Holliday M, Barratt Ross S, Semsarian C, Hill A, Dixon RE, Hool LC. Cytoskeletal disarray increases arrhythmogenic vulnerability during sympathetic stimulation in a model of hypertrophic cardiomyopathy. Sci Rep 2023; 13:11296. [PMID: 37438479 PMCID: PMC10338442 DOI: 10.1038/s41598-023-38296-2] [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: 04/12/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023] Open
Abstract
Familial hypertrophic cardiomyopathy (FHC) patients are advised to avoid strenuous exercise due to increased risk of arrhythmias. Mice expressing the human FHC-causing mutation R403Q in the myosin heavy chain gene (MYH6) recapitulate the human phenotype, including cytoskeletal disarray and increased arrhythmia susceptibility. Following in vivo administration of isoproterenol, mutant mice exhibited tachyarrhythmias, poor recovery and fatigue. Arrhythmias were attenuated with the β-blocker atenolol and protein kinase A inhibitor PKI. Mutant cardiac myocytes had significantly prolonged action potentials and triggered automaticity due to reduced repolarization reserve and connexin 43 expression. Isoproterenol shortened cycle length, and escalated electrical instability. Surprisingly isoproterenol did not increase CaV1.2 current. We found alterations in CaV1.2-β1 adrenergic receptor colocalization assessed using super-resolution nanoscopy, and increased CaV1.2 phosphorylation in mutant hearts. Our results reveal for the first time that altered ion channel expression, co-localization and β-adrenergic receptor signaling associated with myocyte disarray contribute to electrical instability in the R403Q mutant heart.
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Affiliation(s)
| | - Helena M Viola
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia
| | - Danica W Ito
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA
| | - Seakcheng Lim
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Melissa Mangala
- Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
| | - Mira Holliday
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Samantha Barratt Ross
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
- Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Adam Hill
- Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA
| | - Livia C Hool
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia.
- Victor Chang Cardiac Research Institute, Sydney, NSW, Australia.
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Howlett LA, Stevenson-Cocks H, Colman MA, Lancaster MK, Benson AP. Ionic current changes underlying action potential repolarization responses to physiological pacing and adrenergic stimulation in adult rat ventricular myocytes. Physiol Rep 2023; 11:e15766. [PMID: 37495507 PMCID: PMC10371833 DOI: 10.14814/phy2.15766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/28/2023] Open
Abstract
This study aimed to simulate ventricular responses to elevations in myocyte pacing and adrenergic stimulation using a novel electrophysiological rat model and investigate ion channel responses underlying action potential (AP) modulations. Peak ion currents and AP repolarization to 50% and 90% of full repolarization (APD50-90 ) were recorded during simulations at 1-10 Hz pacing under control and adrenergic stimulation conditions. Further simulations were performed with incremental ion current block (L-type calcium current, ICa ; transient outward current, Ito ; slow delayed rectifier potassium current, IKs ; rapid delayed rectifier potassium current, IKr ; inward rectifier potassium current, IK1 ) to identify current influence on AP response to exercise. Simulated APD50-90 closely resembled experimental findings. Rate-dependent increases in IKs (6%-101%), IKr (141%-1339%), and ICa (0%-15%) and reductions in Ito (11%-57%) and IK1 (1%-9%) were observed. Meanwhile, adrenergic stimulation triggered moderate increases in all currents (23%-67%) except IK1 . Further analyses suggest AP plateau is most sensitive to modulations in Ito and ICa while late repolarization is most sensitive to IK1 , ICa , and IKs , with alterations in IKs predominantly stimulating the greatest magnitude of influence on late repolarization (35%-846% APD90 prolongation). The modified Leeds rat model (mLR) is capable of accurately modeling APs during physiological stress. This study highlights the importance of ICa , Ito , IK1, and IKs in controlling electrophysiological responses to exercise. This work will benefit the study of cardiac dysfunction, arrythmia, and disease, though future physiologically relevant experimental studies and model development are required.
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Affiliation(s)
- Luke A Howlett
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | | | | | | | - Alan P Benson
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
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Tajima K, Yamakawa K, Kuwabara Y, Miyazaki C, Sunaga H, Uezono S. Propofol anesthesia decreases the incidence of new-onset postoperative atrial fibrillation compared to desflurane in patients undergoing video-assisted thoracoscopic surgery: A retrospective single-center study. PLoS One 2023; 18:e0285120. [PMID: 37130135 PMCID: PMC10153745 DOI: 10.1371/journal.pone.0285120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/16/2023] [Indexed: 05/03/2023] Open
Abstract
BACKGROUND Postoperative atrial fibrillation (POAF) increases postoperative morbidity, mortality, and length of hospital stay. Propofol is reported to modulate atrial electrophysiology and the cardiac autonomic nervous system. Therefore, we retrospectively examined whether propofol suppresses POAF in patients undergoing video-assisted thoracoscopic surgery (VATS) compared to desflurane. METHODS We retrospectively recruited adult patients who underwent VATS during the period from January 2011 to May 2018 in an academic university hospital. Between continuous propofol and desflurane administration during anesthetic maintenance, we investigated the incidence of new-onset POAF (within 48 hours after surgery) before and after propensity score matching. RESULTS Of the 482 patients, 344 received propofol, and 138 received desflurane during anesthetic maintenance. The incidence of POAF in the propofol group was less than that in the desflurane group (4 [1.2%] vs. 8 patients [5.8%], odds ratio [OR]; 0.161, 95% confidence interval (CI), 0.040-0.653, p = 0.011) in the present study population. After adjustment for propensity score matching (n = 254, n = 127 each group), the incidence of POAF was still less in propofol group than desflurane group (1 [0.8%] vs. 8 patients [6.3%], OR; 0.068, 95% CI: 0.007-0.626, p = 0.018). CONCLUSIONS These retrospective data suggest propofol anesthesia significantly inhibits POAF compared to desflurane anesthesia in patients undergoing VATS. Further prospective studies are needed to elucidate the mechanism of propofol on the inhibition of POAF.
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Affiliation(s)
- Karin Tajima
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Yamakawa
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Yuki Kuwabara
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Chika Miyazaki
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroshi Sunaga
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Shoichi Uezono
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
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Saadeh K, Nantha Kumar N, Fazmin IT, Edling CE, Jeevaratnam K. Anti-malarial drugs: Mechanisms underlying their proarrhythmic effects. Br J Pharmacol 2022; 179:5237-5258. [PMID: 36165125 PMCID: PMC9828855 DOI: 10.1111/bph.15959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/06/2022] [Accepted: 04/28/2022] [Indexed: 01/12/2023] Open
Abstract
Malaria remains the leading cause of parasitic death in the world. Artemisinin resistance is an emerging threat indicating an imminent need for novel combination therapy. Given the key role of mass drug administration, it is pivotal that the safety of anti-malarial drugs is investigated thoroughly prior to widespread use. Cardiotoxicity, most prominently arrhythmic risk, has been a concern for anti-malarial drugs. We clarify the likely underlying mechanisms by which anti-malarial drugs predispose to arrhythmias. These relate to disruption of (1) action potential upstroke due to effects on the sodium currents, (2) action potential repolarisation due to effects on the potassium currents, (3) cellular calcium homeostasis, (4) mitochondrial function and reactive oxygen species production and (5) cardiac fibrosis. Together, these alterations promote arrhythmic triggers and substrates. Understanding these mechanisms is essential to assess the safety of these drugs, stratify patients based on arrhythmic risk and guide future anti-malarial drug development.
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Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordUK,School of Clinical Medicine, Addenbrooke's HospitalUniversity of CambridgeCambridgeUK
| | | | - Ibrahim Talal Fazmin
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordUK,School of Clinical Medicine, Addenbrooke's HospitalUniversity of CambridgeCambridgeUK
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Teng ACT, Gu L, Di Paola M, Lakin R, Williams ZJ, Au A, Chen W, Callaghan NI, Zadeh FH, Zhou YQ, Fatah M, Chatterjee D, Jourdan LJ, Liu J, Simmons CA, Kislinger T, Yip CM, Backx PH, Gourdie RG, Hamilton RM, Gramolini AO. Tmem65 is critical for the structure and function of the intercalated discs in mouse hearts. Nat Commun 2022; 13:6166. [PMID: 36257954 PMCID: PMC9579145 DOI: 10.1038/s41467-022-33303-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/07/2022] [Indexed: 12/24/2022] Open
Abstract
The intercalated disc (ICD) is a unique membrane structure that is indispensable to normal heart function, yet its structural organization is not completely understood. Previously, we showed that the ICD-bound transmembrane protein 65 (Tmem65) was required for connexin43 (Cx43) localization and function in cultured mouse neonatal cardiomyocytes. Here, we investigate the functional and cellular effects of Tmem65 reductions on the myocardium in a mouse model by injecting CD1 mouse pups (3-7 days after birth) with recombinant adeno-associated virus 9 (rAAV9) harboring Tmem65 shRNA, which reduces Tmem65 expression by 90% in mouse ventricles compared to scrambled shRNA injection. Tmem65 knockdown (KD) results in increased mortality which is accompanied by eccentric hypertrophic cardiomyopathy within 3 weeks of injection and progression to dilated cardiomyopathy with severe cardiac fibrosis by 7 weeks post-injection. Tmem65 KD hearts display depressed hemodynamics as measured echocardiographically as well as slowed conduction in optical recording accompanied by prolonged PR intervals and QRS duration in electrocardiograms. Immunoprecipitation and super-resolution microscopy demonstrate a physical interaction between Tmem65 and sodium channel β subunit (β1) in mouse hearts and this interaction appears to be required for both the establishment of perinexal nanodomain structure and the localization of both voltage-gated sodium channel 1.5 (NaV1.5) and Cx43 to ICDs. Despite the loss of NaV1.5 at ICDs, whole-cell patch clamp electrophysiology did not reveal reductions in Na+ currents but did show reduced Ca2+ and K+ currents in Tmem65 KD cardiomyocytes in comparison to control cells. We conclude that disrupting Tmem65 function results in impaired ICD structure, abnormal cardiac electrophysiology, and ultimately cardiomyopathy.
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Affiliation(s)
- Allen C T Teng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
| | - Liyang Gu
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Michelle Di Paola
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Zachary J Williams
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Roanoke, VA, 24016, USA
| | - Aaron Au
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Wenliang Chen
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Neal I Callaghan
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Farigol Hakem Zadeh
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
| | - Yu-Qing Zhou
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Meena Fatah
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Diptendu Chatterjee
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - L Jane Jourdan
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Jack Liu
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Craig A Simmons
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
| | - Thomas Kislinger
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M5G 1L7, Canada
| | - Christopher M Yip
- Institute of Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON, M5S 3G9, Canada
- Donnelly Centre, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, M3J 1P3, Canada
| | - Robert G Gourdie
- The Center for Heart and Reparative Medicine, Fralin Biomedical Research Institute at Virginia Tech. Carilion, Roanoke, VA, 24016, USA
- Virginia Tech Carilion School of Medicine, Roanoke, VA, 24016, USA
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Robert M Hamilton
- The Labatt Family Heart Centre (Dept. of Pediatrics) and Translational Medicine, The Hospital for Sick Children & Research Institute, University of Toronto, Toronto, ON., M5G 1X8, Canada
| | - Anthony O Gramolini
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, M5G 1M1, Canada.
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11
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vom Dahl C, Müller CE, Berisha X, Nagel G, Zimmer T. Coupling the Cardiac Voltage-Gated Sodium Channel to Channelrhodopsin-2 Generates Novel Optical Switches for Action Potential Studies. MEMBRANES 2022; 12:907. [PMID: 36295666 PMCID: PMC9607247 DOI: 10.3390/membranes12100907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Voltage-gated sodium (Na+) channels respond to short membrane depolarization with conformational changes leading to pore opening, Na+ influx, and action potential (AP) upstroke. In the present study, we coupled channelrhodopsin-2 (ChR2), the key ion channel in optogenetics, directly to the cardiac voltage-gated Na+ channel (Nav1.5). Fusion constructs were expressed in Xenopus laevis oocytes, and electrophysiological recordings were performed by the two-microelectrode technique. Heteromeric channels retained both typical Nav1.5 kinetics and light-sensitive ChR2 properties. Switching to the current-clamp mode and applying short blue-light pulses resulted either in subthreshold depolarization or in a rapid change of membrane polarity typically seen in APs of excitable cells. To study the effect of individual K+ channels on the AP shape, we co-expressed either Kv1.2 or hERG with one of the Nav1.5-ChR2 fusions. As expected, both delayed rectifier K+ channels shortened AP duration significantly. Kv1.2 currents remarkably accelerated initial repolarization, whereas hERG channel activity efficiently restored the resting membrane potential. Finally, we investigated the effect of the LQT3 deletion mutant ΔKPQ on the AP shape and noticed an extremely prolonged AP duration that was directly correlated to the size of the non-inactivating Na+ current fraction. In conclusion, coupling of ChR2 to a voltage-gated Na+ channel generates optical switches that are useful for studying the effect of individual ion channels on the AP shape. Moreover, our novel optogenetic approach provides the potential for an application in pharmacology and optogenetic tissue-engineering.
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Affiliation(s)
- Christian vom Dahl
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, 07740 Jena, Germany
| | - Christoph Emanuel Müller
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, 07740 Jena, Germany
| | - Xhevat Berisha
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, 07740 Jena, Germany
| | - Georg Nagel
- Institute of Physiology—Neurophysiology, Julius Maximilians University, 97070 Wuerzburg, Germany
| | - Thomas Zimmer
- Institute of Physiology II, University Hospital Jena, Friedrich Schiller University, 07740 Jena, Germany
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12
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Dong C, Li J, Ding W, Ueda R, Xie X, Wu J, Matsuura H, Horie M. Open channel block of Kv1.5 channels by HMQ1611. Front Pharmacol 2022; 13:965086. [PMID: 36188606 PMCID: PMC9524145 DOI: 10.3389/fphar.2022.965086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
Kv1.5 channels conduct the ultra-rapid delayed rectifier potassium current (IKur). Pharmacological blockade of human Kv1.5 (hKv1.5) has been regarded as an effective treatment of re-entrant based atrial fibrillation, because Kv1.5 is highly expressed in human cardiac atria but scarcely in ventricles. The Kv1.5 blockade is also expected to be used in cancer therapeutics since Kv1.5 is overexpressed in some types of human tumors. Here, we investigated the blockade of hKv1.5 channels by HMQ1611, a symmetrical biphenyl derivative. hKv1.5 channels were heterologously expressed in Chinese hamster ovary cells. The effects of HMQ1611 on wild-type and 13 hKv1.5 mutant channels were examined using the whole-cell patch-clamp method, and molecular docking simulation was conducted to predict the docking position of HMQ1611 within Kv1.5 channels. We showed that HMQ1611 reversibly inhibited the hKv1.5 current in a concentration-dependent manner (IC50 = 2.07 μM). HMQ1611 blockade of hKv1.5 current developed with time during depolarizing voltage-clamp steps, and this blockade was also voltage-dependent with a steep increase over the voltage range for channel openings. HMQ1611 inhibition was significantly reduced in the T479A, T480A, V505A, I508A, L510A, V512A, and V516A hKv1.5 mutant channels. Molecular docking analysis predicted that V505, V512, and T480 were involved in the blocking action of HMQ1611 on hKv1.5 channels. These results suggest that HMQ1611 inhibits hKv1.5 currents as an open channel blocker. Amino acid residues located at the base of the selectivity filter (T479 and T480) and in the S6 segment (V505, I508, L510, V512, and V516) of hKv1.5 appear to constitute potential binding sites for HMQ1611.
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Affiliation(s)
- Chao Dong
- Department of Pharmacology, School of Basic Medical Science, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
- Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an, Shaanxi, China
- Department of Pharmacy, The First Affiliated Hospital of Xi’an Medical University, Xi’an, China
- Department of Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Jiawei Li
- Department of Pharmacology, School of Basic Medical Science, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
- Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an, Shaanxi, China
| | - Weiguang Ding
- Department of Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Rika Ueda
- Department of Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Xiaolu Xie
- Department of Cardiovascular Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Jie Wu
- Department of Pharmacology, School of Basic Medical Science, Xi’an Jiaotong University Health Science Center, Xi’an, Shaanxi, China
- Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an, Shaanxi, China
- Department of Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
- *Correspondence: Jie Wu,
| | - Hiroshi Matsuura
- Department of Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan
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13
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Allosteric inhibitors targeting the calmodulin-PIP2 interface of SK4 K + channels for atrial fibrillation treatment. Proc Natl Acad Sci U S A 2022; 119:e2202926119. [PMID: 35969786 PMCID: PMC9407317 DOI: 10.1073/pnas.2202926119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Ca2+-activated SK4 K+ channel is gated by Ca2+-calmodulin (CaM) and is expressed in immune cells, brain, and heart. A cryoelectron microscopy (cryo-EM) structure of the human SK4 K+ channel recently revealed four CaM molecules per channel tetramer, where the apo CaM C-lobe and the holo CaM N-lobe interact with the proximal carboxyl terminus and the linker S4-S5, respectively, to gate the channel. Here, we show that phosphatidylinositol 4-5 bisphosphate (PIP2) potently activates SK4 channels by docking to the boundary of the CaM-binding domain. An allosteric blocker, BA6b9, was designed to act to the CaM-PIP2-binding domain, a previously untargeted region of SK4 channels, at the interface of the proximal carboxyl terminus and the linker S4-S5. Site-directed mutagenesis, molecular docking, and patch-clamp electrophysiology indicate that BA6b9 inhibits SK4 channels by interacting with two specific residues, Arg191 and His192 in the linker S4-S5, not conserved in SK1-SK3 subunits, thereby conferring selectivity and preventing the Ca2+-CaM N-lobe from properly interacting with the channel linker region. Immunohistochemistry of the SK4 channel protein in rat hearts showed a widespread expression in the sarcolemma of atrial myocytes, with a sarcomeric striated Z-band pattern, and a weaker occurrence in the ventricle but a marked incidence at the intercalated discs. BA6b9 significantly prolonged atrial and atrioventricular effective refractory periods in rat isolated hearts and reduced atrial fibrillation induction ex vivo. Our work suggests that inhibition of SK4 K+ channels by targeting drugs to the CaM-PIP2-binding domain provides a promising anti-arrhythmic therapy.
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14
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Heijman J, Dobrev D. Molecular determinants and therapeutic potential of focal ectopic activity: more than meets the Iti. Eur Heart J 2022; 43:4208-4210. [PMID: 35822877 DOI: 10.1093/eurheartj/ehac357] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University of Duisburg-Essen, Essen, Germany.,Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA.,Departments of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Canada
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15
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Electroacupuncture Ameliorates Acute Myocardial Ischemic Injury and Long QT Interval in Mice through the α1A-Adrenergic Receptor: Electrophysiological, Morphological, and Molecular Evidence. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1984706. [PMID: 35814274 PMCID: PMC9262560 DOI: 10.1155/2022/1984706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/10/2022] [Indexed: 11/18/2022]
Abstract
Acute myocardial ischemia (AMI) is a condition caused by a decrease in blood flow to the heart that can sometimes predispose to acquired long QT syndrome (LQTS), thereby resulting in sudden cardiac death. Recent evidence indicates that electroacupuncture (EA) can alleviate MI injury, but its specific mechanism remains unclear. This study was aimed at investigating the efficacy of EA, which utilizes α1A-adrenergic receptors (α1A-AR) in alleviating MI injury as well as the resulting LQTS. The AMI model was established by ligating the left anterior descending arteries (LAD) of both the wild-type and α1A gene-knockout mice and treating them with EA for three consecutive days. A PowerLab 16 physiological recorder was used to collect the electrocardiogram (ECG) while the serum creatine kinase isoenzymes (CK-MB), lactate dehydrogenase (LDH), and norepinephrine (NE) levels in myocardial tissue were determined by using the enzyme-linked immunosorbent assay (ELISA) kit. Moreover, TTC staining was used to observe the myocardial ischemic area, while H&E and TUNEL staining determined the pathological morphology of the myocardium. Quantitative real-time PCR (qRT-PCR) was used to detect the α1A mRNA, and Western blot was used to detect the specific proteins, such as α1A, cleaved caspase-3, Gq, PLC, p-PKCα, and p-hERG. Our results showed that EA could effectively reduce elevated ST-segment, shorten the extended QT interval, and reduce the serum myocardial enzyme content and the degree of pathological injury in wild mice with MI. EA can also decrease the expression of α1A-AR, PLC, p-PKCα, and NE content in myocardial tissues of wild mice, while those of p-hERG increased in ischemic myocardial tissue. These findings suggested that α1A-AR is involved in the development of MI as well as LQTS. Additionally, EA treatment improves the cardiac function and ischemic long QT interval and plays an important role in reducing the hERG inhibition through the α1A-AR-mediated Gq/PLC/PKCα pathway and myocardial apoptosis. Hence, it is suggested that α1A-AR might become a potential target for EA in treating AMI treatment of myocardial ischemia injury and acquired long QT intervals caused by MI.
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16
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Sarcoplasmic Reticulum Ca2+ Dysregulation in the Pathophysiology of Inherited Arrhythmia: An Update. Biochem Pharmacol 2022; 200:115059. [DOI: 10.1016/j.bcp.2022.115059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/19/2022]
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17
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Ross RL, Mavria G, Del Galdo F, Elies J. Downregulation of Vascular Hemeoxygenase-1 Leads to Vasculopathy in Systemic Sclerosis. Front Physiol 2022; 13:900631. [PMID: 35600300 PMCID: PMC9117635 DOI: 10.3389/fphys.2022.900631] [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: 03/21/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
Systemic sclerosis (SSc) is a terminal disease characterized by vasculopathy, tissue fibrosis, and autoimmunity. Although the exact etiology of SSc remains unknown, endothelial dysfunction, oxidative stress, and calcium handling dysregulation have been associated with a large number of SSc-related complications such as neointima formation, vasculogenesis, pulmonary arterial hypertension, impaired angiogenesis, and cardiac arrhythmias. Hemeoxygenase-1 (HO-1) is an antioxidant enzyme involved in multiple biological actions in the cardiovascular system including vascular tone, angiogenesis, cellular proliferation, apoptosis, and oxidative stress. The aim of this work was to investigate the physiological role of HO-1 and its relevance in the cardiovascular complications occurring in SSc. We found that, in early phases of SSc, the expression of HO-1 in dermal fibroblast is lower compared to those isolated from healthy control individuals. This is particularly relevant as reduction of the HO-1/CO signaling pathway is associated with endothelial dysfunction and vasculopathy. We show evidence of the role of HO-1/carbon monoxide (CO) signaling pathway in calcium handling. Using an in vitro model of pulmonary arterial hypertension (PAH) we investigated the role of HO-1 in Ca2+ mobilization from intracellular stores. Our results indicate that HO-1 regulates calcium release from intracellular stores of human pulmonary arterial endothelial cells. We interrogated the activity of HO-1 in angiogenesis using an organotypic co-culture of fibroblast-endothelial cell. Inhibition of HO-1 significantly reduced the ability of endothelial cells to form tubules. We further investigated if this could be associated with cell motility or migration of endothelial cells into the extracellular matrix synthesized by fibroblasts. By mean of holographic imaging, we studied the morphological and functional features of endothelial cells in the presence of an HO-1 activator and selective inhibitors. Our results demonstrate that inhibition of HO-1 significantly reduces cell proliferation and cell motility (migration) of cultured endothelial cells, whilst activation of HO-1 does not modify either morphology, proliferation or motility. In addition, we investigated the actions of CO on the Kv7.1 (KCQN1) channel current, an important component of the cardiac action potential repolarization. Using electrophysiology (whole-cell patch-clamp in a recombinant system overexpressing the KCQN1 channel), we assessed the regulation of KCQN1 by CO. CORM-2, a CO donor, significantly reduced the Kv7.1 current, suggesting that HO-1/CO signaling may play a role in the modulation of the cardiac action potential via regulation of this ion channel. In summary, our results indicate a clear link between: 1) downregulation of HO-1/CO signaling; and 2) pathophysiological processes occurring in early phases of SSc, such as calcium homeostasis dysregulation, impaired angiogenesis and cardiac arrhythmias. A better understanding of the canonical actions (mainly due to the biological actions of CO), and non-canonical actions of HO-1, as well as the interaction of HO-1/CO signaling with other gasotransmitters in SSc will contribute to the development of novel therapeutic approaches.
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Affiliation(s)
- Rebecca L Ross
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
- Scleroderma Programme, NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds, United Kingdom
| | - Georgia Mavria
- Signal Transduction and Tumour Microenvironment Group, Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, United Kingdom
| | - Francesco Del Galdo
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
- Scleroderma Programme, NIHR Leeds Musculoskeletal Biomedical Research Centre, Leeds, United Kingdom
| | - Jacobo Elies
- Cardiovascular Research Group, Faculty of Life Sciences, University of Bradford, Bradford, United Kingdom
- *Correspondence: Jacobo Elies,
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18
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Koponen M, Marjamaa A, Väänänen H, Tuiskula AM, Kontula K, Swan H, Viitasalo M. Effects of beta-blockers on ventricular repolarization documented by 24-h electrocardiography in long-QT syndrome type 2. Heart Rhythm 2022; 19:1491-1498. [PMID: 35525424 DOI: 10.1016/j.hrthm.2022.04.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/11/2022] [Accepted: 04/27/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Long QT syndrome (LQTS) is an inherited arrhythmia disorder characterized by ventricular repolarization abnormalities and a risk of sudden cardiac death. The electrophysiological components generating the high risk of arrhythmias in LQTS are prolonged repolarization, increased dispersion of repolarization, and early afterdepolarizations, which are clinically estimated as QT interval, T-wave peak to end (TPE) interval, and T2/T1-wave amplitude ratio, respectively. In experimental LQTS type 2 (LQT2) models, beta-blockers decrease dispersion of repolarization and prevent early afterdepolarizations. In clinical studies among LQT2 patients beta-blockers are more effective against exercise-induced than arousal-induced cardiac events. OBJECTIVES AND METHODS The aim of the study was to investigate the effects of beta-blocker therapy on QT and TPE intervals, and maximal T2/T1-wave amplitude ratios recorded by 24-h electrocardiograms (ECG) among 25 LQT2 patients. RESULTS Beta-blocker therapy decreased the maximal T2/T1-wave amplitude ratio from 2.9±1.1 to 1.8±0.7 (p<0.001), but did not change pause-induced T2/T1-wave amplitude ratio. Under medication abrupt maximal TPE intervals were shorter at heart rates of 75 beats/min or over, and maximal QT intervals were shorter at a heart rate of 100 beats/min. CONCLUSIONS Beta-blockers stabilize ventricular repolarization in LQT2 by reducing electrocardiographic early afterdepolarizations, and by reducing abrupt prolongation of electrocardiographic dispersion of repolarization and ventricular repolarization duration at elevated heart rates. The effect of beta-blockers on pause-induced electrocardiographic early afterdepolarizations is weak. The findings provide electrocardiographic explanation for the protective effects of beta-blockers against exercise-induced cardiac events in LQT2.
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Affiliation(s)
- Mikael Koponen
- Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland.
| | - Annukka Marjamaa
- Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland
| | - Heikki Väänänen
- Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Annukka M Tuiskula
- Department of Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland; HUS Diagnostic Center, Laboratory of Genetics, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Kimmo Kontula
- Department of Medicine, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Heikki Swan
- Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland
| | - Matti Viitasalo
- Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland
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19
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Morciano G, Rimessi A, Patergnani S, Vitto VAM, Danese A, Kahsay A, Palumbo L, Bonora M, Wieckowski MR, Giorgi C, Pinton P. Calcium dysregulation in heart diseases: Targeting calcium channels to achieve a correct calcium homeostasis. Pharmacol Res 2022; 177:106119. [PMID: 35131483 DOI: 10.1016/j.phrs.2022.106119] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/01/2022] [Accepted: 02/03/2022] [Indexed: 12/16/2022]
Abstract
Intracellular calcium signaling is a universal language source shared by the most part of biological entities inside cells that, all together, give rise to physiological and functional anatomical units, the organ. Although preferentially recognized as signaling between cell life and death processes, in the heart it assumes additional relevance considered the importance of calcium cycling coupled to ATP consumption in excitation-contraction coupling. The concerted action of a plethora of exchangers, channels and pumps inward and outward calcium fluxes where needed, to convert energy and electric impulses in muscle contraction. All this without realizing it, thousands of times, every day. An improper function of those proteins (i.e., variation in expression, mutations onset, dysregulated channeling, differential protein-protein interactions) being part of this signaling network triggers a short circuit with severe acute and chronic pathological consequences reported as arrhythmias, cardiac remodeling, heart failure, reperfusion injury and cardiomyopathies. By acting with chemical, peptide-based and pharmacological modulators of these players, a correction of calcium homeostasis can be achieved accompanied by an amelioration of clinical symptoms. This review will focus on all those defects in calcium homeostasis which occur in the most common cardiac diseases, including myocardial infarction, arrhythmia, hypertrophy, heart failure and cardiomyopathies. This part will be introduced by the state of the art on the proteins involved in calcium homeostasis in cardiomyocytes and followed by the therapeutic treatments that to date, are able to target them and to revert the pathological phenotype.
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Affiliation(s)
- Giampaolo Morciano
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; Maria Cecilia Hospital, GVM Care & Research, 48033 Cotignola, RA, Italy.
| | - Alessandro Rimessi
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Simone Patergnani
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Veronica A M Vitto
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Alberto Danese
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Asrat Kahsay
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Laura Palumbo
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Massimo Bonora
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism. Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies (LTTA), Section of Experimental Medicine, Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy; Maria Cecilia Hospital, GVM Care & Research, 48033 Cotignola, RA, Italy.
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20
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Abstract
PURPOSE OF REVIEW Total ceramide levels in cardiac tissue relate to cardiac dysfunction in animal models. However, emerging evidence suggests that the fatty acyl chain length of ceramides also impacts their relationship to cardiac function. This review explores evidence regarding the relationship between ceramides and left ventricular dysfunction and heart failure. It further explores possible mechanisms underlying these relationships. RECENT FINDINGS In large, community-based cohorts, a higher ratio of specific plasma ceramides, C16 : 0/C24 : 0, related to worse left ventricular dysfunction. Increased left ventricular mass correlated with plasma C16 : 0/C24 : 0, but this relationship became nonsignificant after adjustment for multiple comparisons. Decreased left atrial function and increased left atrial size also related to C16 : 0/C24 : 0. Furthermore, increased incident heart failure, overall cardiovascular disease (CVD) mortality and all-cause mortality were associated with higher C16 : 0/C24 : 0 (or lower C24 : 0/C16 : 0). Finally, a number of possible biological mechanisms are outlined supporting the link between C16 : 0/C24 : 0 ceramides, ceramide signalling and CVD. SUMMARY High cardiac levels of total ceramides are noted in heart failure. In the plasma, C16 : 0/C24 : 0 ceramides may be a valuable biomarker of preclinical left ventricular dysfunction, remodelling, heart failure and mortality. Continued exploration of the mechanisms underlying these profound relationships may help develop specific lipid modulators to combat cardiac dysfunction and heart failure.
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Affiliation(s)
- Lauren K. Park
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Valene Garr-Barry
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Juan Hong
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
| | - John Heebink
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Rajan Sah
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
| | - Linda R. Peterson
- Department of Medicine, Division of Cardiology, Washington University School of Medicine, Saint Louis, Missouri
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21
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Sirish P, Diloretto DA, Thai PN, Chiamvimonvat N. The Critical Roles of Proteostasis and Endoplasmic Reticulum Stress in Atrial Fibrillation. Front Physiol 2022; 12:793171. [PMID: 35058801 PMCID: PMC8764384 DOI: 10.3389/fphys.2021.793171] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 12/08/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) remains the most common arrhythmia seen clinically. The incidence of AF is increasing due to the aging population. AF is associated with a significant increase in morbidity and mortality, yet current treatment paradigms have proven largely inadequate. Therefore, there is an urgent need to develop new effective therapeutic strategies for AF. The endoplasmic reticulum (ER) in the heart plays critical roles in the regulation of excitation-contraction coupling and cardiac function. Perturbation in the ER homeostasis due to intrinsic and extrinsic factors, such as inflammation, oxidative stress, and ischemia, leads to ER stress that has been linked to multiple conditions including diabetes mellitus, neurodegeneration, cancer, heart disease, and cardiac arrhythmias. Recent studies have documented the critical roles of ER stress in the pathophysiological basis of AF. Using an animal model of chronic pressure overload, we demonstrate a significant increase in ER stress in atrial tissues. Moreover, we demonstrate that treatment with a small molecule inhibitor to inhibit the soluble epoxide hydrolase enzyme in the arachidonic acid metabolism significantly reduces ER stress as well as atrial electrical and structural remodeling. The current review article will attempt to provide a perspective on our recent understandings and current knowledge gaps on the critical roles of proteostasis and ER stress in AF progression.
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Affiliation(s)
- Padmini Sirish
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, United States.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, United States
| | - Daphne A Diloretto
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, United States
| | - Phung N Thai
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, United States.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, United States
| | - Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, United States.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, United States.,Department of Pharmacology, University of California, Davis, Davis, CA, United States
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22
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MicroRNA-365 regulates human cardiac action potential duration. Nat Commun 2022; 13:220. [PMID: 35017523 PMCID: PMC8752767 DOI: 10.1038/s41467-021-27856-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 12/16/2021] [Indexed: 12/21/2022] Open
Abstract
Abnormalities of ventricular action potential cause malignant cardiac arrhythmias and sudden cardiac death. Here, we aim to identify microRNAs that regulate the human cardiac action potential and ask whether their manipulation allows for therapeutic modulation of action potential abnormalities. Quantitative analysis of the microRNA targetomes in human cardiac myocytes identifies miR-365 as a primary microRNA to regulate repolarizing ion channels. Action potential recordings in patient-specific induced pluripotent stem cell-derived cardiac myocytes show that elevation of miR-365 significantly prolongs action potential duration in myocytes derived from a Short-QT syndrome patient, whereas specific inhibition of miR-365 normalizes pathologically prolonged action potential in Long-QT syndrome myocytes. Transcriptome analyses in these cells at bulk and single-cell level corroborate the key cardiac repolarizing channels as direct targets of miR-365, together with functionally synergistic regulation of additional action potential-regulating genes by this microRNA. Whole-cell patch-clamp experiments confirm miR-365-dependent regulation of repolarizing ionic current Iks. Finally, refractory period measurements in human myocardial slices substantiate the regulatory effect of miR-365 on action potential in adult human myocardial tissue. Our results delineate miR-365 to regulate human cardiac action potential duration by targeting key factors of cardiac repolarization.
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23
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Howlett LA, Kirton HM, Al‐Owais MM, Steele D, Lancaster MK. Action potential responses to changes in stimulation frequency and isoproterenol in rat ventricular myocytes. Physiol Rep 2022; 10:e15166. [PMID: 35076184 PMCID: PMC8787729 DOI: 10.14814/phy2.15166] [Citation(s) in RCA: 2] [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: 10/26/2021] [Revised: 12/16/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023] Open
Abstract
PURPOSE Current understanding of ventricular action potential adaptation to physiological stress is generally based on protocols using non-physiological rates and conditions isolating rate effects from escalating adrenergic stimulation. To permit refined understanding, ventricular action potentials were assessed across physiological pacing frequencies in the presence and absence of adrenergic stimuli. Isolated and combined effects were analyzed to assess their ability to replicate in-vivo responses. METHODS Steady-state action potentials from ventricular myocytes isolated from male Wistar rats (3 months; N = 8 animals) were recorded at 37°C with steady-state pacing at 1, 2, 4, 6, 8 and 10 Hz using whole-cell patch-clamp. Action potential repolarization to 25, 50, 75, 90 and 100% of full repolarization (APD25-100 ) was compared before and after 5 nM, 100 nM and 1 µM isoproterenol doses. RESULTS A Repeated measures ANOVA found APD50-90 shortened with 5 nM isoproterenol infusion by 6-25% (but comparable across doses) (p ≤ 0.03). Pacing frequencies emulating a normal rat heart rate (6 Hz) prolonged APD50 23% compared with 1 Hz pacing. Frequencies emulating exercise or stress (10 Hz) shortened APD90 (29%). CONCLUSION These results demonstrate modest action potential shortening in response to adrenergic stimulation and elevations in pacing beyond physiological resting rates. Our findings indicate changes in action potential plateau and late repolarization predominantly underlie simulated exercise responses in the rat heart. This work provides novel action potential reference data and will help model cardiac responses to physiological stimuli in the rat heart via computational techniques.
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Affiliation(s)
| | | | | | - Derek Steele
- Faculty of Biological SciencesUniversity of LeedsLeedsUK
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24
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Hegyi B, Ko CY, Bossuyt J, Bers DM. Two-hit mechanism of cardiac arrhythmias in diabetic hyperglycaemia: reduced repolarization reserve, neurohormonal stimulation, and heart failure exacerbate susceptibility. Cardiovasc Res 2021; 117:2781-2793. [PMID: 33483728 PMCID: PMC8683706 DOI: 10.1093/cvr/cvab006] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 01/10/2021] [Indexed: 12/11/2022] Open
Abstract
AIMS Diabetic hyperglycaemia is associated with increased arrhythmia risk. We aimed to investigate whether hyperglycaemia alone can be accountable for arrhythmias or whether it requires the presence of additional pathological factors. METHODS AND RESULTS Action potentials (APs) and arrhythmogenic spontaneous diastolic activities were measured in isolated murine ventricular, rabbit atrial, and ventricular myocytes acutely exposed to high glucose. Acute hyperglycaemia increased the short-term variability (STV) of action potential duration (APD), enhanced delayed afterdepolarizations, and the inducibility of APD alternans during tachypacing in both murine and rabbit atrial and ventricular myocytes. Hyperglycaemia also prolonged APD in mice and rabbit atrial cells but not in rabbit ventricular myocytes. However, rabbit ventricular APD was more strongly depressed by block of late Na+ current (INaL) during hyperglycaemia, consistent with elevated INaL in hyperglycaemia. All the above proarrhythmic glucose effects were Ca2+-dependent and abolished by CaMKII inhibition. Importantly, when the repolarization reserve was reduced by pharmacological inhibition of K+ channels (either Ito, IKr, IKs, or IK1) or hypokalaemia, acute hyperglycaemia further prolonged APD and further increased STV and alternans in rabbit ventricular myocytes. Likewise, when rabbit ventricular myocytes were pretreated with isoproterenol or angiotensin II, hyperglycaemia significantly prolonged APD, increased STV and promoted alternans. Moreover, acute hyperglycaemia markedly prolonged APD and further enhanced STV in failing rabbit ventricular myocytes. CONCLUSION We conclude that even though hyperglycaemia alone can enhance cellular proarrhythmic mechanisms, a second hit which reduces the repolarization reserve or stimulates G protein-coupled receptor signalling greatly exacerbates cardiac arrhythmogenesis in diabetic hyperglycaemia.
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Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Christopher Y Ko
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, 451 Health Sciences Drive, CA 95616, USA
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25
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Hou P, Du X, An H. Editorial: Ion Channels: Therapeutic Targets for Neurological Disease. Front Mol Neurosci 2021; 14:797327. [PMID: 34867195 PMCID: PMC8636780 DOI: 10.3389/fnmol.2021.797327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 10/25/2021] [Indexed: 11/20/2022] Open
Affiliation(s)
- Panpan Hou
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, Macau University of Science and Technology, Taipa, Macao SAR, China.,State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao SAR, China
| | - Xiaona Du
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, China
| | - Hailong An
- Key Laboratory of Molecular Biophysics of Hebei, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, China
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26
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Monteiro O, Bhaskar A, Ng AKM, Murdoch CE, Baptista-Hon DT. Computer-based virtual laboratory simulations: LabHEART cardiac physiology practical. ADVANCES IN PHYSIOLOGY EDUCATION 2021; 45:856-868. [PMID: 34473584 DOI: 10.1152/advan.00094.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Practical demonstration of cardiomyocyte function requires substantial preparation, a source of freshly isolated animal hearts, and specialized equipment. Even where such resources are available, it is not conducive for demonstration to any more than a few students at a time. These approaches are also not consistent with the 3R principle (replacement, reduction, and refinement) of ethical use of animals. We present an implementation of the LabHEART software, developed by Donald Bers and Jose Puglisi, for medical students. Prior to the activity, students had lectures covering the physiological and pharmacological aspects of cardiac excitation-contraction (EC) coupling. We used this problem-based activity to help students consolidate their knowledge and to allow a hands-on approach to explore the key features of EC coupling. Students simulate and measure action potentials, intracellular calcium changes, and cardiomyocyte contraction. They also apply drugs that target ion channels (e.g., nifedipine or tetrodotoxin) or sympathetic input (using isoproterenol) and explore changes to EC coupling. Furthermore, by modifying the biophysical parameters of key ion channels involved in the electrical activity of the heart, students also explore the effect of channelopathies such as long QT syndromes. We describe approaches to implement this activity in a flipped classroom format, with recorded lecture materials provided ahead of the practical to facilitate active learning. We also describe our experiences implementing this activity online. The content and difficulty of the activity can be altered to suit individual courses and is also amenable to promote peer-driven learning.
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Affiliation(s)
- Olivia Monteiro
- Department of Biomedical Sciences, Faculty of Medicine, Macau University of Science and Technology, Taipa, Macau S.A.R., China
| | - Anand Bhaskar
- Department of Biomedical Sciences, Faculty of Medicine, Macau University of Science and Technology, Taipa, Macau S.A.R., China
| | - Anna K M Ng
- Department of Biomedical Sciences, Faculty of Medicine, Macau University of Science and Technology, Taipa, Macau S.A.R., China
| | - Colin E Murdoch
- Systems Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Daniel T Baptista-Hon
- Department of Biomedical Sciences, Faculty of Medicine, Macau University of Science and Technology, Taipa, Macau S.A.R., China
- Systems Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
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27
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Cluitmans MJM, Bear LR, Nguyên UC, van Rees B, Stoks J, Ter Bekke RMA, Mihl C, Heijman J, Lau KD, Vigmond E, Bayer J, Belterman CNW, Abell E, Labrousse L, Rogier J, Bernus O, Haïssaguerre M, Hassink RJ, Dubois R, Coronel R, Volders PGA. Noninvasive detection of spatiotemporal activation-repolarization interactions that prime idiopathic ventricular fibrillation. Sci Transl Med 2021; 13:eabi9317. [PMID: 34788076 DOI: 10.1126/scitranslmed.abi9317] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Matthijs J M Cluitmans
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands.,Philips Research, 5656 AE Eindhoven, Netherlands
| | | | - Uyên C Nguyên
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
| | - Bianca van Rees
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
| | - Job Stoks
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
| | - Rachel M A Ter Bekke
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
| | - Casper Mihl
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands.,Department of Radiology, Maastricht University Medical Centre, 6200 MD Maastricht, Netherlands
| | - Jordi Heijman
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
| | - Kevin D Lau
- Philips Research, 5656 AE Eindhoven, Netherlands
| | | | | | - Charly N W Belterman
- Department of Experimental Cardiology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, Netherlands
| | | | - Louis Labrousse
- IHU LIRYC, 33600 Pessac, France.,University of Bordeaux, 33000 Bordeaux, France.,Hôpital Haut Lévêque, University Hospital of Bordeaux, 33604 Bordeaux, France
| | - Julien Rogier
- IHU LIRYC, 33600 Pessac, France.,University of Bordeaux, 33000 Bordeaux, France.,Hôpital Haut Lévêque, University Hospital of Bordeaux, 33604 Bordeaux, France
| | - Olivier Bernus
- IHU LIRYC, 33600 Pessac, France.,University of Bordeaux, 33000 Bordeaux, France
| | - Michel Haïssaguerre
- IHU LIRYC, 33600 Pessac, France.,University of Bordeaux, 33000 Bordeaux, France.,Hôpital Haut Lévêque, University Hospital of Bordeaux, 33604 Bordeaux, France
| | - Rutger J Hassink
- Department of Cardiology, University Medical Centre Utrecht, 3584 CX Utrecht, Netherlands
| | | | - Ruben Coronel
- IHU LIRYC, 33600 Pessac, France.,Department of Experimental Cardiology, Amsterdam University Medical Centre, 1105 AZ Amsterdam, Netherlands
| | - Paul G A Volders
- Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, Netherlands
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28
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Sung E, Prakosa A, Trayanova NA. Analyzing the Role of Repolarization Gradients in Post-infarct Ventricular Tachycardia Dynamics Using Patient-Specific Computational Heart Models. Front Physiol 2021; 12:740389. [PMID: 34658925 PMCID: PMC8514757 DOI: 10.3389/fphys.2021.740389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/06/2021] [Indexed: 11/20/2022] Open
Abstract
Aims: Disease-induced repolarization heterogeneity in infarcted myocardium contributes to VT arrhythmogenesis but how apicobasal and transmural (AB-TM) repolarization gradients additionally affect post-infarct VT dynamics is unknown. The goal of this study is to assess how AB-TM repolarization gradients impact post-infarct VT dynamics using patient-specific heart models. Method: 3D late gadolinium-enhanced cardiac magnetic resonance images were acquired from seven post-infarct patients. Models representing the patient-specific scar and infarct border zone distributions were reconstructed without (baseline) and with repolarization gradients along both the AB-TM axes. AB only and TM only models were created to assess the effects of each ventricular gradient on VT dynamics. VTs were induced in all models via rapid pacing. Results: Ten baseline VTs were induced. VT inducibility in AB-TM models was not significantly different from baseline (p>0.05). Reentry pathways in AB-TM models were different than baseline pathways due to alterations in the location of conduction block (p<0.05). VT exit sites in AB-TM models were different than baseline VT exit sites (p<0.05). VT inducibility of AB only and TM only models were not significantly different than that of baseline (p>0.05) or AB-TM models (p>0.05). Reentry pathways and VT exit sites in AB only and TM only models were different than in baseline (p<0.05). Lastly, repolarization gradients uncovered multiple VT morphologies with different reentrant pathways and exit sites within the same structural, conducting channels. Conclusion: VT inducibility was not impacted by the addition of AB-TM repolarization gradients, but the VT reentrant pathway and exit sites were greatly affected due to modulation of conduction block. Thus, during ablation procedures, physiological and pharmacological factors that impact the ventricular repolarization gradient might need to be considered when targeting the VTs.
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Affiliation(s)
- Eric Sung
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States.,Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, United States
| | - Adityo Prakosa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States.,Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, United States
| | - Natalia A Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States.,Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, United States
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29
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Chen L, He Y, Wang X, Ge J, Li H. Ventricular voltage-gated ion channels: Detection, characteristics, mechanisms, and drug safety evaluation. Clin Transl Med 2021; 11:e530. [PMID: 34709746 PMCID: PMC8516344 DOI: 10.1002/ctm2.530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac voltage-gated ion channels (VGICs) play critical roles in mediating cardiac electrophysiological signals, such as action potentials, to maintain normal heart excitability and contraction. Inherited or acquired alterations in the structure, expression, or function of VGICs, as well as VGIC-related side effects of pharmaceutical drug delivery can result in abnormal cellular electrophysiological processes that induce life-threatening cardiac arrhythmias or even sudden cardiac death. Hence, to reduce possible heart-related risks, VGICs must be acknowledged as important targets in drug discovery and safety studies related to cardiac disease. In this review, we first summarize the development and application of electrophysiological techniques that are employed in cardiac VGIC studies alone or in combination with other techniques such as cryoelectron microscopy, optical imaging and optogenetics. Subsequently, we describe the characteristics, structure, mechanisms, and functions of various well-studied VGICs in ventricular myocytes and analyze their roles in and contributions to both physiological cardiac excitability and inherited cardiac diseases. Finally, we address the implications of the structure and function of ventricular VGICs for drug safety evaluation. In summary, multidisciplinary studies on VGICs help researchers discover potential targets of VGICs and novel VGICs in heart, enrich their knowledge of the properties and functions, determine the operation mechanisms of pathological VGICs, and introduce groundbreaking trends in drug therapy strategies, and drug safety evaluation.
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Affiliation(s)
- Lulan Chen
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Yue He
- Department of CardiologyShanghai Xuhui District Central Hospital & Zhongshan‐xuhui HospitalShanghaiChina
| | - Xiangdong Wang
- Institute of Clinical Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
| | - Hua Li
- Department of Cardiology, Shanghai Institute of Cardiovascular DiseasesShanghai Xuhui District Central Hospital & Zhongshan‐xuhui Hospital, Zhongshan Hospital, Fudan UniversityShanghaiChina
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30
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Lind L, Araujo JA, Barchowsky A, Belcher S, Berridge BR, Chiamvimonvat N, Chiu WA, Cogliano VJ, Elmore S, Farraj AK, Gomes AV, McHale CM, Meyer-Tamaki KB, Posnack NG, Vargas HM, Yang X, Zeise L, Zhou C, Smith MT. Key Characteristics of Cardiovascular Toxicants. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:95001. [PMID: 34558968 PMCID: PMC8462506 DOI: 10.1289/ehp9321] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND The concept of chemical agents having properties that confer potential hazard called key characteristics (KCs) was first developed to identify carcinogenic hazards. Identification of KCs of cardiovascular (CV) toxicants could facilitate the systematic assessment of CV hazards and understanding of assay and data gaps associated with current approaches. OBJECTIVES We sought to develop a consensus-based synthesis of scientific evidence on the KCs of chemical and nonchemical agents known to cause CV toxicity along with methods to measure them. METHODS An expert working group was convened to discuss mechanisms associated with CV toxicity. RESULTS The group identified 12 KCs of CV toxicants, defined as exogenous agents that adversely interfere with function of the CV system. The KCs were organized into those primarily affecting cardiac tissue (numbers 1-4 below), the vascular system (5-7), or both (8-12), as follows: 1) impairs regulation of cardiac excitability, 2) impairs cardiac contractility and relaxation, 3) induces cardiomyocyte injury and death, 4) induces proliferation of valve stroma, 5) impacts endothelial and vascular function, 6) alters hemostasis, 7) causes dyslipidemia, 8) impairs mitochondrial function, 9) modifies autonomic nervous system activity, 10) induces oxidative stress, 11) causes inflammation, and 12) alters hormone signaling. DISCUSSION These 12 KCs can be used to help identify pharmaceuticals and environmental pollutants as CV toxicants, as well as to better understand the mechanistic underpinnings of their toxicity. For example, evidence exists that fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)] air pollution, arsenic, anthracycline drugs, and other exogenous chemicals possess one or more of the described KCs. In conclusion, the KCs could be used to identify potential CV toxicants and to define a set of test methods to evaluate CV toxicity in a more comprehensive and standardized manner than current approaches. https://doi.org/10.1289/EHP9321.
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Affiliation(s)
- Lars Lind
- Department of Medical Sciences, Clinical Epidemiology, University of Uppsala, Sweden
| | - Jesus A. Araujo
- Division of Cardiology, David Geffen School of Medicine at University of California Los Angeles (UCLA), UCLA, Los Angeles, California, USA
- Department of Environmental Health Sciences, Fielding School of Public Health and Molecular Biology Institute, UCLA, Los Angeles, California, USA
| | - Aaron Barchowsky
- Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pennsylvania, USA
| | - Scott Belcher
- Department of Biological Sciences, North Carolina State University, North Carolina, USA
| | - Brian R. Berridge
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Nipavan Chiamvimonvat
- Department of Internal Medicine, University of California, Davis, Davis, California, USA
| | - Weihsueh A. Chiu
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Vincent J. Cogliano
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency (EPA), Oakland, California, USA
| | - Sarah Elmore
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency (EPA), Oakland, California, USA
| | - Aimen K. Farraj
- Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Aldrin V. Gomes
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, Davis, California, USA
| | - Cliona M. McHale
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | | | - Nikki Gillum Posnack
- Children’s National Heart Institute and the Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Hospital, Washington, DC, USA
| | - Hugo M. Vargas
- Translational Safety & Bioanalytical Sciences, Amgen, Inc., Thousand Oaks, California, USA
| | - Xi Yang
- Division of Pharmacology and Toxicology, Office of Cardiology, Hematology, Endocrinology, and Nephrology, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency (EPA), Oakland, California, USA
| | - Changcheng Zhou
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, California, USA
| | - Martyn T. Smith
- Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California, USA
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31
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Gallego M, Zayas-Arrabal J, Alquiza A, Apellaniz B, Casis O. Electrical Features of the Diabetic Myocardium. Arrhythmic and Cardiovascular Safety Considerations in Diabetes. Front Pharmacol 2021; 12:687256. [PMID: 34305599 PMCID: PMC8295895 DOI: 10.3389/fphar.2021.687256] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/15/2021] [Indexed: 12/20/2022] Open
Abstract
Diabetes is a chronic metabolic disease characterized by hyperglycemia in the absence of treatment. Among the diabetes-associated complications, cardiovascular disease is the major cause of mortality and morbidity in diabetic patients. Diabetes causes a complex myocardial dysfunction, referred as diabetic cardiomyopathy, which even in the absence of other cardiac risk factors results in abnormal diastolic and systolic function. Besides mechanical abnormalities, altered electrical function is another major feature of the diabetic myocardium. Both type 1 and type 2 diabetic patients often show cardiac electrical remodeling, mainly a prolonged ventricular repolarization visible in the electrocardiogram as a lengthening of the QT interval duration. The underlying mechanisms at the cellular level involve alterations on the expression and activity of several cardiac ion channels and their associated regulatory proteins. Consequent changes in sodium, calcium and potassium currents collectively lead to a delay in repolarization that can increase the risk of developing life-threatening ventricular arrhythmias and sudden death. QT duration correlates strongly with the risk of developing torsade de pointes, a form of ventricular tachycardia that can degenerate into ventricular fibrillation. Therefore, QT prolongation is a qualitative marker of proarrhythmic risk, and analysis of ventricular repolarization is therefore required for the approval of new drugs. To that end, the Thorough QT/QTc analysis evaluates QT interval prolongation to assess potential proarrhythmic effects. In addition, since diabetic patients have a higher risk to die from cardiovascular causes than individuals without diabetes, cardiovascular safety of the new antidiabetic drugs must be carefully evaluated in type 2 diabetic patients. These cardiovascular outcome trials reveal that some glucose-lowering drugs actually reduce cardiovascular risk. The mechanism of cardioprotection might involve a reduction of the risk of developing arrhythmia.
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Affiliation(s)
- Mónica Gallego
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
| | - Julián Zayas-Arrabal
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
| | - Amaia Alquiza
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
| | - Beatriz Apellaniz
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
| | - Oscar Casis
- Department of Physiology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
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32
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Zayas-Arrabal J, Alquiza A, Tuncay E, Turan B, Gallego M, Casis O. Molecular and Electrophysiological Role of Diabetes-Associated Circulating Inflammatory Factors in Cardiac Arrhythmia Remodeling in a Metabolic-Induced Model of Type 2 Diabetic Rat. Int J Mol Sci 2021; 22:ijms22136827. [PMID: 34202017 PMCID: PMC8268936 DOI: 10.3390/ijms22136827] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 12/29/2022] Open
Abstract
Background: Diabetic patients have prolonged cardiac repolarization and higher risk of arrhythmia. Besides, diabetes activates the innate immune system, resulting in higher levels of plasmatic cytokines, which are described to prolong ventricular repolarization. Methods: We characterize a metabolic model of type 2 diabetes (T2D) with prolonged cardiac repolarization. Sprague-Dawley rats were fed on a high-fat diet (45% Kcal from fat) for 6 weeks, and a low dose of streptozotozin intraperitoneally injected at week 2. Body weight and fasting blood glucose were measured and electrocardiograms of conscious animals were recorded weekly. Plasmatic lipid profile, insulin, cytokines, and arrhythmia susceptibility were determined at the end of the experimental period. Outward K+ currents and action potentials were recorded in isolated ventricular myocytes by patch-clamp. Results: T2D animals showed insulin resistance, hyperglycemia, and elevated levels of plasma cholesterol, triglycerides, TNFα, and IL-1b. They also developed bradycardia and prolonged QTc-interval duration that resulted in increased susceptibility to severe ventricular tachycardia under cardiac challenge. Action potential duration (APD) was prolonged in control cardiomyocytes incubated 24 h with plasma isolated from diabetic rats. However, adding TNFα and IL-1b receptor blockers to the serum of diabetic animals prevented the increased APD. Conclusions: The elevation of the circulating levels of TNFα and IL-1b are responsible for impaired ventricular repolarization and higher susceptibility to cardiac arrhythmia in our metabolic model of T2D.
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Affiliation(s)
- Julian Zayas-Arrabal
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Amaia Alquiza
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, 06100 Ankara, Turkey;
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, 06510 Ankara, Turkey;
| | - Monica Gallego
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
| | - Oscar Casis
- Departament of Physiology, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, 01006 Vitoria-Gasteiz, Spain; (J.Z.-A.); (A.A.); (M.G.)
- Correspondence: ; Tel.: +34-945013033
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33
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Herrera-Pérez S, Campos-Ríos A, Rueda-Ruzafa L, Lamas JA. Contribution of K2P Potassium Channels to Cardiac Physiology and Pathophysiology. Int J Mol Sci 2021; 22:ijms22126635. [PMID: 34205717 PMCID: PMC8234311 DOI: 10.3390/ijms22126635] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 12/28/2022] Open
Abstract
Years before the first two-pore domain potassium channel (K2P) was cloned, certain ion channels had already been demonstrated to be present in the heart with characteristics and properties usually attributed to the TREK channels (a subfamily of K2P channels). K2P channels were later detected in cardiac tissue by RT-PCR, although the distribution of the different K2P subfamilies in the heart seems to depend on the species analyzed. In order to collect relevant information in this regard, we focus here on the TWIK, TASK and TREK cardiac channels, their putative roles in cardiac physiology and their implication in coronary pathologies. Most of the RNA expression data and electrophysiological recordings available to date support the presence of these different K2P subfamilies in distinct cardiac cells. Likewise, we show how these channels may be involved in certain pathologies, such as atrial fibrillation, long QT syndrome and Brugada syndrome.
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34
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Chang Y, Li YN, Bai R, Wu F, Ma S, Saleem A, Zhang S, Jiang Y, Dong T, Guo T, Hang C, Lu WJ, Jiang H, Lan F. hERG-deficient human embryonic stem cell-derived cardiomyocytes for modelling QT prolongation. Stem Cell Res Ther 2021; 12:278. [PMID: 33962658 PMCID: PMC8103639 DOI: 10.1186/s13287-021-02346-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/19/2021] [Indexed: 11/10/2022] Open
Abstract
Background Long-QT syndrome type 2 (LQT2) is a common malignant hereditary arrhythmia. Due to the lack of suitable animal and human models, the pathogenesis of LQT2 caused by human ether-a-go-go-related gene (hERG) deficiency is still unclear. In this study, we generated an hERG-deficient human cardiomyocyte (CM) model that simulates ‘human homozygous hERG mutations’ to explore the underlying impact of hERG dysfunction and the genotype–phenotype relationship of hERG deficiency. Methods The KCNH2 was knocked out in the human embryonic stem cell (hESC) H9 line using the CRISPR/Cas9 system. Using a chemically defined differentiation protocol, we obtained and verified hERG-deficient CMs. Subsequently, high-throughput microelectrode array (MEA) assays and drug interventions were performed to characterise the electrophysiological signatures of hERG-deficient cell lines. Results Our results showed that KCNH2 knockout did not affect the pluripotency or differentiation efficiency of H9 cells. Using high-throughput MEA assays, we found that the electric field potential duration and action potential duration of hERG-deficient CMs were significantly longer than those of normal CMs. The hERG-deficient lines also exhibited irregular rhythm and some early afterdepolarisations. Moreover, we used the hERG-deficient human CM model to evaluate the potency of agents (nifedipine and magnesium chloride) that may ameliorate the phenotype. Conclusions We established an hERG-deficient human CM model that exhibited QT prolongation, irregular rhythm and sensitivity to other ion channel blockers. This model serves as an important tool that can aid in understanding the fundamental impact of hERG dysfunction, elucidate the genotype–phenotype relationship of hERG deficiency and facilitate drug development. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02346-1.
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Affiliation(s)
- Yun Chang
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Ya-Nan Li
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Rui Bai
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Fujian Wu
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Shuhong Ma
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Amina Saleem
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Siyao Zhang
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Youxu Jiang
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Tao Dong
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Tianwei Guo
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Chengwen Hang
- Department of Cardiology, Peking University Third Hospital, Beijing, 100191, China
| | - Wen-Jing Lu
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China.,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China
| | - Hongfeng Jiang
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China. .,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China.
| | - Feng Lan
- Beijing Laboratory for Cardiovascular Precision Medicine, The Key Laboratory of Biomedical Engineering for Cardiovascular Disease Research, The Key Laboratory of Remodeling-Related Cardiovascular Disease, Ministry of Education, Beijing Anzhen Hospital, Capital Medical University, Research Institute Building, Room 323, 2 Anzhen Road, Chaoyang District, Beijing, 100029, China. .,Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, 100029, China. .,State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Key Laboratory of Application of Pluripotent Stem Cells in Heart Regeneration, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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35
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Targeting of Potassium Channels in Cardiac Arrhythmias. Trends Pharmacol Sci 2021; 42:491-506. [PMID: 33858691 DOI: 10.1016/j.tips.2021.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/14/2021] [Accepted: 03/17/2021] [Indexed: 02/07/2023]
Abstract
Cardiomyocytes are endowed with a complex repertoire of ion channels, responsible for the generation of action potentials (APs), travelling waves of electrical excitation, propagating throughout the heart and leading to cardiac contractions. Cardiac AP waveforms are shaped by a striking diversity of K+ channels. The pivotal role of K+ channels in cardiac health and disease is underscored by the dramatic impact that K+ channel dysfunction has on cardiac arrhythmias. The development of drugs targeted to specific K+ channels is expected to provide an optimized approach to antiarrhythmic therapy. Here, we review the functional roles of cardiac potassium channels under normal and diseased states. We survey current antiarrhythmic drugs (AADs) targeted to voltage-gated and Ca2+-activated K+ channels and highlight future research opportunities.
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36
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Miranda WE, Guo J, Mesa-Galloso H, Corradi V, Lees-Miller JP, Tieleman DP, Duff HJ, Noskov SY. Lipid regulation of hERG1 channel function. Nat Commun 2021; 12:1409. [PMID: 33658490 PMCID: PMC7930123 DOI: 10.1038/s41467-021-21681-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 01/29/2021] [Indexed: 01/31/2023] Open
Abstract
The lipid regulation of mammalian ion channel function has emerged as a fundamental mechanism in the control of electrical signalling and transport specificity in various cell types. In this work, we combine molecular dynamics simulations, mutagenesis, and electrophysiology to provide mechanistic insights into how lipophilic molecules (ceramide-sphingolipid probe) alter gating kinetics and K+ currents of hERG1. We show that the sphingolipid probe induced a significant left shift of activation voltage, faster deactivation rates, and current blockade comparable to traditional hERG1 blockers. Microseconds-long MD simulations followed by experimental mutagenesis elucidated ceramide specific binding locations at the interface between the pore and voltage sensing domains. This region constitutes a unique crevice present in mammalian channels with a non-swapped topology. The combined experimental and simulation data provide evidence for ceramide-induced allosteric modulation of the channel by a conformational selection mechanism.
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Affiliation(s)
- Williams E Miranda
- Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada
| | - Jiqing Guo
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, 3280 Hospital Dr., University of Calgary, Calgary, AB, Canada
| | - Haydee Mesa-Galloso
- Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada
| | - Valentina Corradi
- Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada
| | - James P Lees-Miller
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, 3280 Hospital Dr., University of Calgary, Calgary, AB, Canada
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada.
| | - Henry J Duff
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, 3280 Hospital Dr., University of Calgary, Calgary, AB, Canada.
| | - Sergei Yu Noskov
- Centre for Molecular Simulation and Department of Biological Sciences, 507 Campus Drive, University of Calgary, Calgary, AB, Canada.
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37
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Kabakov AY, Sengun E, Lu Y, Roder K, Bronk P, Baggett B, Turan NN, Moshal KS, Koren G. Three-Week-Old Rabbit Ventricular Cardiomyocytes as a Novel System to Study Cardiac Excitation and EC Coupling. Front Physiol 2021; 12:672360. [PMID: 34867432 PMCID: PMC8637404 DOI: 10.3389/fphys.2021.672360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/06/2021] [Indexed: 01/14/2023] Open
Abstract
Cardiac arrhythmias significantly contribute to cardiovascular morbidity and mortality. The rabbit heart serves as an accepted model system for studying cardiac cell excitation and arrhythmogenicity. Accordingly, primary cultures of adult rabbit ventricular cardiomyocytes serve as a preferable model to study molecular mechanisms of human cardiac excitation. However, the use of adult rabbit cardiomyocytes is often regarded as excessively costly. Therefore, we developed and characterized a novel low-cost rabbit cardiomyocyte model, namely, 3-week-old ventricular cardiomyocytes (3wRbCMs). Ventricular myocytes were isolated from whole ventricles of 3-week-old New Zealand White rabbits of both sexes by standard enzymatic techniques. Using wheat germ agglutinin, we found a clear T-tubule structure in acutely isolated 3wRbCMs. Cells were adenovirally infected (multiplicity of infection of 10) to express Green Fluorescent Protein (GFP) and cultured for 48 h. The cells showed action potential duration (APD90 = 253 ± 24 ms) and calcium transients similar to adult rabbit cardiomyocytes. Freshly isolated and 48-h-old-cultured cells expressed critical ion channel proteins: calcium voltage-gated channel subunit alpha1 C (Cavα1c), sodium voltage-gated channel alpha subunit 5 (Nav1.5), potassium voltage-gated channel subfamily D member 3 (Kv4.3), and subfamily A member 4 (Kv1.4), and also subfamily H member 2 (RERG. Kv11.1), KvLQT1 (K7.1) protein and inward-rectifier potassium channel (Kir2.1). The cells displayed an appropriate electrophysiological phenotype, including fast sodium current (I Na), transient outward potassium current (I to), L-type calcium channel peak current (I Ca,L), rapid and slow components of the delayed rectifier potassium current (I Kr and I Ks), and inward rectifier (I K1). Although expression of the channel proteins and some currents decreased during the 48 h of culturing, we conclude that 3wRbCMs are a new, low-cost alternative to the adult-rabbit-cardiomyocytes system, which allows the investigation of molecular mechanisms of cardiac excitation on morphological, biochemical, genetic, physiological, and biophysical levels.
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Affiliation(s)
- Anatoli Y Kabakov
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Elif Sengun
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States.,Department of Pharmacology, Institute of Graduate Studies in Health Sciences, Istanbul University, Istanbul, Türkiye
| | - Yichun Lu
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Karim Roder
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Peter Bronk
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Brett Baggett
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Nilüfer N Turan
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Karni S Moshal
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
| | - Gideon Koren
- Department of Medicine, Division of Cardiology, Cardiovascular Research Center, Rhode Island Hospital, The Warren Alpert Medical School of Brown University, Providence, RI, United States
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38
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Varró A, Tomek J, Nagy N, Virág L, Passini E, Rodriguez B, Baczkó I. Cardiac transmembrane ion channels and action potentials: cellular physiology and arrhythmogenic behavior. Physiol Rev 2020; 101:1083-1176. [PMID: 33118864 DOI: 10.1152/physrev.00024.2019] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Cardiac arrhythmias are among the leading causes of mortality. They often arise from alterations in the electrophysiological properties of cardiac cells and their underlying ionic mechanisms. It is therefore critical to further unravel the pathophysiology of the ionic basis of human cardiac electrophysiology in health and disease. In the first part of this review, current knowledge on the differences in ion channel expression and properties of the ionic processes that determine the morphology and properties of cardiac action potentials and calcium dynamics from cardiomyocytes in different regions of the heart are described. Then the cellular mechanisms promoting arrhythmias in congenital or acquired conditions of ion channel function (electrical remodeling) are discussed. The focus is on human-relevant findings obtained with clinical, experimental, and computational studies, given that interspecies differences make the extrapolation from animal experiments to human clinical settings difficult. Deepening the understanding of the diverse pathophysiology of human cellular electrophysiology will help in developing novel and effective antiarrhythmic strategies for specific subpopulations and disease conditions.
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Affiliation(s)
- András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - Jakub Tomek
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Norbert Nagy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary.,MTA-SZTE Cardiovascular Pharmacology Research Group, Hungarian Academy of Sciences, Szeged, Hungary
| | - László Virág
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
| | - Elisa Passini
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Blanca Rodriguez
- Department of Computer Science, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, Szeged, Hungary
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39
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Zhou HS, Peng DW, Lai YY, Li Q, Zhao JF, Deng CY, Yang H, Li T, Wang ZY, Xu YW, Xue YM, Wu SL, Guo HM, Rao F. Activation of PKCα participates in the reduction of Ikur in atrial myocytes induced by tumour necrosis factor-α. Clin Exp Pharmacol Physiol 2020; 48:435-442. [PMID: 32966616 DOI: 10.1111/1440-1681.13407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 11/30/2022]
Abstract
The atrial-specific ultra-rapid delayed rectifier K+ current (Ikur) plays an important role in the progression of atrial fibrillation (AF). Because inflammation is known to lead to the onset of AF, we aimed to investigate whether tumour necrosis factor-α (TNF-α) played a role in regulating Ikur and the potential signalling pathways involved. Whole-cell patch-clamp and biochemical assays were used to study the regulation and expression of Ikur in myocytes and in tissues from left atrial appendages (LAAs) obtained from patients with sinus rhythm (SR) or AF, as well as in rat cardiomyocytes (H9c2 cells) and mouse atrial myocytes (HL-1 cells). Ikur current density was markedly reduced in atrial myocytes from AF patients compared with SR controls. Reduction of Kv1.5 protein levels was accompanied by increased expression of TNF-α and protein kinase C (PKC)α activation in AF patients. Treatment with TNF-α dose-dependently reduced Ikur and protein expression of Kv1.5 but not Kv3.1b in H9c2 cells and HL-1 cells. TNF-α also increased activity of PKCα. Specific PKCα inhibitor Gö6976 alleviated the reduction in Ikur induced by TNF-α, but not the reduction in Kv1.5 protein. TNF-α was involved in the electrical remodelling associated with AF, probably by depressing Ikur in atrial myocytes via activation of PKCα.
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Affiliation(s)
- Hui-Shan Zhou
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Panyu Central Hospital, Guangzhou, China
| | - De-Wei Peng
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Ying-Yu Lai
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Qian Li
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Jun-Fei Zhao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Chun-Yu Deng
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Hui Yang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Teng Li
- Arrhythmia Department, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China
| | - Zhao-Yu Wang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Yu-Wen Xu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Yu-Mei Xue
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Shu-Lin Wu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Hui-Ming Guo
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Fang Rao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
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40
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Saadeh K, Shivkumar K, Jeevaratnam K. Targeting the β-adrenergic receptor in the clinical management of congenital long QT syndrome. Ann N Y Acad Sci 2020; 1474:27-46. [PMID: 32901453 DOI: 10.1111/nyas.14425] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/10/2020] [Accepted: 06/09/2020] [Indexed: 01/01/2023]
Abstract
The long QT syndrome (LQTS) is largely treated pharmacologically with β-blockers, despite the role of sympathetic activity in LQTS being poorly understood. Using the trigger-substrate model of cardiac arrhythmias in this review, we amalgamate current experimental and clinical data from both animal and human studies to explain the mechanism of adrenergic stimulation and blockade on LQT arrhythmic risk and hence assess the efficacy of β-adrenoceptor blockade in the management of LQTS. In LQTS1 and LQTS2, sympathetic stimulation increases arrhythmic risk by enhancing early afterdepolarizations and transmural dispersion of repolarization. β-Blockers successfully reduce cardiac events by reducing these triggers and substrates; however, these effects are less marked in LQTS2 compared with LQTS1. In LQTS3, clinical and experimental investigations of the effects of sympathetic stimulation and β-blocker use have produced contradictory findings, resulting in significant clinical uncertainty. We offer explanations for these contradicting results relating to study sample size, the dose of the β-blocker administered associated with its off-target Na+ channel effects, as well as the type of β-blocker used. We conclude that the antiarrhythmic efficacy of β-blockers is a genotype-specific phenomenon, and hence the use of β-blockers in clinical practice should be genotype dependent.
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Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Kalyanam Shivkumar
- UCLA Cardiac Arrhythmia Centre, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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41
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Mohindra R, Lin S. The drugs don’t matter: Cardiovascular drugs have minimal effects on amplitude spectral area during ventricular fibrillation. Resuscitation 2020; 151:205-207. [DOI: 10.1016/j.resuscitation.2020.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
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42
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Assiri AA, Mourad N, Shao M, Kiel P, Liu W, Skaar TC, Overholser BR. MicroRNA 362-3p Reduces hERG-related Current and Inhibits Breast Cancer Cells Proliferation. Cancer Genomics Proteomics 2020; 16:433-442. [PMID: 31659098 DOI: 10.21873/cgp.20147] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND/AIM hERG potassium channels enhance tumor invasiveness and breast cancer proliferation. MicroRNA (miRNA) dysregulation during cancer controls gene regulation. The objective of this study was to identify miRNAs that regulate hERG expression in breast cancer. MATERIALS AND METHODS Putative miRNAs targeting hERG were identified by bioinformatic approaches and screened using a 3'UTR luciferase assay. Functional assessments of endogenous hERG regulation were made using whole-cell electrophysiology, proliferation assays, and cell-cycle analyses following miRNA, hERG siRNA, or control transfection. RESULTS miR-362-3p targeted hERG 3'UTR and was associated with higher survival rates in patients with breast cancer (HR=0.39, 95%CI=0.18-0.82). Enhanced miR-362-3p expression reduced hERG expression, peak current, and cell proliferation in cultured breast cancer cells (p<0.05). CONCLUSION miR-362-3p mediates the transcriptional regulation of hERG and is associated with survival in breast cancer. The potential for miR-362-3p to serve as a biomarker and inform therapeutic strategies warrants further investigation.
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Affiliation(s)
- Abdullah A Assiri
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, IN, U.S.A.,Department of Clinical Pharmacy, King Khalid University, Abha, Kingdom of Saudi Arabia
| | - Noha Mourad
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, IN, U.S.A.,College of Pharmacy, Manchester University, Fort Wayne, IN, U.S.A
| | - Minghai Shao
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, IN, U.S.A
| | - Patrick Kiel
- Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, U.S.A
| | - Wanqing Liu
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, U.S.A
| | - Todd C Skaar
- Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, U.S.A
| | - Brian R Overholser
- Department of Pharmacy Practice, College of Pharmacy, Purdue University, West Lafayette, IN, U.S.A. .,Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, U.S.A
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43
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Gilbert G, Demydenko K, Dries E, Puertas RD, Jin X, Sipido K, Roderick HL. Calcium Signaling in Cardiomyocyte Function. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035428. [PMID: 31308143 DOI: 10.1101/cshperspect.a035428] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rhythmic increases in intracellular Ca2+ concentration underlie the contractile function of the heart. These heart muscle-wide changes in intracellular Ca2+ are induced and coordinated by electrical depolarization of the cardiomyocyte sarcolemma by the action potential. Originating at the sinoatrial node, conduction of this electrical signal throughout the heart ensures synchronization of individual myocytes into an effective cardiac pump. Ca2+ signaling pathways also regulate gene expression and cardiomyocyte growth during development and in pathology. These fundamental roles of Ca2+ in the heart are illustrated by the prevalence of altered Ca2+ homeostasis in cardiovascular diseases. Indeed, heart failure (an inability of the heart to support hemodynamic needs), rhythmic disturbances, and inappropriate cardiac growth all share an involvement of altered Ca2+ handling. The prevalence of these pathologies, contributing to a third of all deaths in the developed world as well as to substantial morbidity makes understanding the mechanisms of Ca2+ handling and dysregulation in cardiomyocytes of great importance.
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Affiliation(s)
- Guillaume Gilbert
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Kateryna Demydenko
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Eef Dries
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Rosa Doñate Puertas
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Xin Jin
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - Karin Sipido
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, BE3000 Leuven, Belgium
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44
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Kistamás K, Veress R, Horváth B, Bányász T, Nánási PP, Eisner DA. Calcium Handling Defects and Cardiac Arrhythmia Syndromes. Front Pharmacol 2020; 11:72. [PMID: 32161540 PMCID: PMC7052815 DOI: 10.3389/fphar.2020.00072] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
Abstract
Calcium ions (Ca2+) play a major role in the cardiac excitation-contraction coupling. Intracellular Ca2+ concentration increases during systole and falls in diastole thereby determining cardiac contraction and relaxation. Normal cardiac function also requires perfect organization of the ion currents at the cellular level to drive action potentials and to maintain action potential propagation and electrical homogeneity at the tissue level. Any imbalance in Ca2+ homeostasis of a cardiac myocyte can lead to electrical disturbances. This review aims to discuss cardiac physiology and pathophysiology from the elementary membrane processes that can cause the electrical instability of the ventricular myocytes through intracellular Ca2+ handling maladies to inherited and acquired arrhythmias. Finally, the paper will discuss the current therapeutic approaches targeting cardiac arrhythmias.
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Affiliation(s)
- Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Dental Physiology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - David A Eisner
- Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
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45
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Taylor KC, Kang PW, Hou P, Yang ND, Kuenze G, Smith JA, Shi J, Huang H, White KM, Peng D, George AL, Meiler J, McFeeters RL, Cui J, Sanders CR. Structure and physiological function of the human KCNQ1 channel voltage sensor intermediate state. eLife 2020; 9:e53901. [PMID: 32096762 PMCID: PMC7069725 DOI: 10.7554/elife.53901] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Voltage-gated ion channels feature voltage sensor domains (VSDs) that exist in three distinct conformations during activation: resting, intermediate, and activated. Experimental determination of the structure of a potassium channel VSD in the intermediate state has previously proven elusive. Here, we report and validate the experimental three-dimensional structure of the human KCNQ1 voltage-gated potassium channel VSD in the intermediate state. We also used mutagenesis and electrophysiology in Xenopus laevisoocytes to functionally map the determinants of S4 helix motion during voltage-dependent transition from the intermediate to the activated state. Finally, the physiological relevance of the intermediate state KCNQ1 conductance is demonstrated using voltage-clamp fluorometry. This work illuminates the structure of the VSD intermediate state and demonstrates that intermediate state conductivity contributes to the unusual versatility of KCNQ1, which can function either as the slow delayed rectifier current (IKs) of the cardiac action potential or as a constitutively active epithelial leak current.
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Affiliation(s)
- Keenan C Taylor
- Department of Biochemistry, Vanderbilt UniversityNashvilleUnited States
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
| | - Po Wei Kang
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Panpan Hou
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Nien-Du Yang
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Georg Kuenze
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
- Departments of Chemistry and Pharmacology, Vanderbilt UniversityNashvilleUnited States
| | - Jarrod A Smith
- Department of Biochemistry, Vanderbilt UniversityNashvilleUnited States
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
| | - Jingyi Shi
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Hui Huang
- Department of Biochemistry, Vanderbilt UniversityNashvilleUnited States
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
| | - Kelli McFarland White
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Dungeng Peng
- Department of Biochemistry, Vanderbilt UniversityNashvilleUnited States
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
- Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical CenterNashvilleUnited States
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
- Departments of Chemistry and Pharmacology, Vanderbilt UniversityNashvilleUnited States
- Department of Bioinformatics, Vanderbilt University Medical CenterNashvilleUnited States
| | - Robert L McFeeters
- Department of Chemistry, University of Alabama in HuntsvilleHuntsvilleUnited States
| | - Jianmin Cui
- Department of Biomedical Engineering, Center for the Investigation of Membrane Excitability Disorders, and Cardiac Bioelectricity, and Arrhythmia Center, Washington University in St. LouisSt. LouisUnited States
| | - Charles R Sanders
- Department of Biochemistry, Vanderbilt UniversityNashvilleUnited States
- Center for Structural Biology, Vanderbilt UniversityNashvilleUnited States
- Department of Medicine, Vanderbilt University Medical CenterNashvilleUnited States
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46
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Two-stage electro-mechanical coupling of a K V channel in voltage-dependent activation. Nat Commun 2020; 11:676. [PMID: 32015334 PMCID: PMC6997178 DOI: 10.1038/s41467-020-14406-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/18/2019] [Indexed: 01/04/2023] Open
Abstract
In voltage-gated potassium (KV) channels, the voltage-sensing domain (VSD) undergoes sequential activation from the resting state to the intermediate state and activated state to trigger pore opening via electro-mechanical (E-M) coupling. However, the spatial and temporal details underlying E-M coupling remain elusive. Here, utilizing KV7.1's unique two open states, we report a two-stage E-M coupling mechanism in voltage-dependent gating of KV7.1 as triggered by VSD activations to the intermediate and then activated state. When the S4 segment transitions to the intermediate state, the hand-like C-terminus of the VSD-pore linker (S4-S5L) interacts with the pore in the same subunit. When S4 then proceeds to the fully-activated state, the elbow-like hinge between S4 and S4-S5L engages with the pore of the neighboring subunit to activate conductance. This two-stage hand-and-elbow gating mechanism elucidates distinct tissue-specific modulations, pharmacology, and disease pathogenesis of KV7.1, and likely applies to numerous domain-swapped KV channels.
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47
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Bers DM, Kohl P, Chen-Izu Y. Mechanics and energetics in cardiac arrhythmias and heart failure. J Physiol 2020; 598:1275-1277. [PMID: 31998965 DOI: 10.1113/jp279385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Donald M Bers
- Department of Pharmacology and Cardiovascular Research Institute, University of California, Davis, CA, USA
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Centre, and Faculty of Medicine, University of Freiburg, Freiburg, D-79110, Germany
| | - Ye Chen-Izu
- Department of Pharmacology and Cardiovascular Research Institute, University of California, Davis, CA, USA
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48
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Zhang H, Zhang H, Wang C, Wang Y, Zou R, Shi C, Guan B, Gamper N, Xu Y. Auxiliary subunits control biophysical properties and response to compound NS5806 of the Kv4 potassium channel complex. FASEB J 2019; 34:807-821. [PMID: 31914636 PMCID: PMC6972550 DOI: 10.1096/fj.201902010rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 12/19/2022]
Abstract
Kv4 pore‐forming subunits co‐assemble with β‐subunits including KChIP2 and DPP6 and the resultant complexes conduct cardiac transient outward K+ current (Ito). Compound NS5806 has been shown to potentate Ito in canine cardiomyocytes; however, its effects on Ito in other species yet to be determined. We found that NS5806 inhibited native Ito in a concentration‐dependent manner (0.1~30 μM) in both mouse ventricular cardiomyocytes and human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs), but potentiated Ito in the canine cardiomyocytes. In HEK293 cells co‐transfected with cloned Kv4.3 (or Kv4.2) and β‐subunit KChIP2, NS5806 significantly increased the peak current amplitude and slowed the inactivation. In contrast, NS5806 suppressed the current and accelerated inactivation of the channels when cells were co‐transfected with Kv4.3 (or Kv4.2), KChIP2 and another β‐subunit, DPP6‐L (long isoform). Western blot analysis showed that DPP6‐L was dominantly expressed in both mouse ventricular myocardium and hiPSC‐CMs, while it was almost undetectable in canine ventricular myocardium. In addition, low level of DPP6‐S expression was found in canine heart, whereas levels of KChIP2 expression were comparable among all three species. siRNA knockdown of DPP6 antagonized the Ito inhibition by NS5806 in hiPSC‐CMs. Molecular docking simulation suggested that DPP6‐L may associate with KChIP2 subunits. Mutations of putative KChIP2‐interacting residues of DPP6‐L reversed the inhibitory effect of NS5806 into potentiation of the current. We conclude that a pharmacological modulator can elicit opposite regulatory effects on Kv4 channel complex among different species, depending on the presence of distinct β‐subunits. These findings provide novel insight into the molecular design and regulation of cardiac Ito. Since Ito is a potential therapeutic target for treatment of multiple cardiovascular diseases, our data will facilitate the development of new therapeutic Ito modulators.
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Affiliation(s)
- Hongxue Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Hua Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chanjuan Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Yuhong Wang
- Institute of Masteria Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ruya Zou
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Chenxia Shi
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Bingcai Guan
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
| | - Nikita Gamper
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Yanfang Xu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China
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49
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Souza DSD, Menezes-Filho JERD, Santos-Miranda A, Jesus ICGD, Silva Neto JA, Guatimosim S, Cruz JS, Vasconcelos CMLD. Calcium overload-induced arrhythmia is suppressed by farnesol in rat heart. Eur J Pharmacol 2019; 859:172488. [DOI: 10.1016/j.ejphar.2019.172488] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 01/01/2023]
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50
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Hou P, Shi J, White KM, Gao Y, Cui J. ML277 specifically enhances the fully activated open state of KCNQ1 by modulating VSD-pore coupling. eLife 2019; 8:e48576. [PMID: 31329101 PMCID: PMC6684268 DOI: 10.7554/elife.48576] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/22/2019] [Indexed: 12/16/2022] Open
Abstract
Upon membrane depolarization, the KCNQ1 potassium channel opens at the intermediate (IO) and activated (AO) states of the stepwise voltage-sensing domain (VSD) activation. In the heart, KCNQ1 associates with KCNE1 subunits to form IKs channels that regulate heart rhythm. KCNE1 suppresses the IO state so that the IKs channel opens only to the AO state. Here, we tested modulations of human KCNQ1 channels by an activator ML277 in Xenopus oocytes. It exclusively changes the pore opening properties of the AO state without altering the IO state, but does not affect VSD activation. These observations support a distinctive mechanism responsible for the VSD-pore coupling at the AO state that is sensitive to ML277 modulation. ML277 provides insights and a tool to investigate the gating mechanism of KCNQ1 channels, and our study reveals a new strategy for treating long QT syndrome by specifically enhancing the AO state of native IKs currents.
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Affiliation(s)
- Panpan Hou
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | - Jingyi Shi
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | - Kelli McFarland White
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
| | | | - Jianmin Cui
- Department of Biomedical EngineeringWashington UniversitySt. LouisUnited States
- Center for the Investigation of Membrane Excitability DisordersWashington UniversitySt. LouisUnited States
- Cardiac Bioelectricity and Arrhythmia CenterWashington UniversitySt. LouisUnited States
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