1
|
Saponaro A, Krumbach JH, Chaves-Sanjuan A, Sharifzadeh AS, Porro A, Castelli R, Hamacher K, Bolognesi M, DiFrancesco D, Clarke OB, Thiel G, Moroni A. Structural determinants of ivabradine block of the open pore of HCN4. Proc Natl Acad Sci U S A 2024; 121:e2402259121. [PMID: 38917012 PMCID: PMC11228525 DOI: 10.1073/pnas.2402259121] [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: 02/07/2024] [Accepted: 05/26/2024] [Indexed: 06/27/2024] Open
Abstract
HCN1-4 channels are the molecular determinants of the If/Ih current that crucially regulates cardiac and neuronal cell excitability. HCN dysfunctions lead to sinoatrial block (HCN4), epilepsy (HCN1), and chronic pain (HCN2), widespread medical conditions awaiting subtype-specific treatments. Here, we address the problem by solving the cryo-EM structure of HCN4 in complex with ivabradine, to date the only HCN-specific drug on the market. Our data show ivabradine bound inside the open pore at 3 Å resolution. The structure unambiguously proves that Y507 and I511 on S6 are the molecular determinants of ivabradine binding to the inner cavity, while F510, pointing outside the pore, indirectly contributes to the block by controlling Y507. Cysteine 479, unique to the HCN selectivity filter (SF), accelerates the kinetics of block. Molecular dynamics simulations further reveal that ivabradine blocks the permeating ion inside the SF by electrostatic repulsion, a mechanism previously proposed for quaternary ammonium ions.
Collapse
Affiliation(s)
- Andrea Saponaro
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan 20133, Italy
| | - Jan H Krumbach
- Department of Physics, Technische Universität Darmstadt, Darmstadt 64289, Germany
- Department of Biology and Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
| | | | | | - Alessandro Porro
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Roberta Castelli
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Kay Hamacher
- Department of Physics, Technische Universität Darmstadt, Darmstadt 64289, Germany
- Department of Biology and Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
| | | | - Dario DiFrancesco
- Department of Biosciences, University of Milan, Milan 20133, Italy
- Institute of Biophysics-Milan, Consiglio Nazionale delle Ricerche, Milan 20133, Italy
| | - Oliver B Clarke
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY 10032
- Irving Institute for Clinical and Translational Research, Columbia University, New York, NY 10032
| | - Gerhard Thiel
- Department of Biology and Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Anna Moroni
- Department of Biosciences, University of Milan, Milan 20133, Italy
- Institute of Biophysics-Milan, Consiglio Nazionale delle Ricerche, Milan 20133, Italy
| |
Collapse
|
2
|
Guedes MR, de Noronha SISR, Chírico MTT, da Costa GDC, de Freitas Castro T, de Brito RCF, Vieira LG, Reis TO, Ribeiro MC, Reis AB, Carneiro CM, Bezerra FS, Montano N, da Silva VJD, de Menezes RCA, Chianca-Jr DA, Silva FCDS. Ivabradine restores tonic cardiovascular autonomic control and reduces tachycardia, hypertension and left ventricular inflammation in post-weaning protein malnourished rats. Life Sci 2024; 346:122636. [PMID: 38614307 DOI: 10.1016/j.lfs.2024.122636] [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: 01/25/2024] [Revised: 03/22/2024] [Accepted: 04/10/2024] [Indexed: 04/15/2024]
Abstract
Malnutrition results in autonomic imbalance and heart hypertrophy. Overexpression of hyperpolarization-activated cyclic nucleotide-gated channels (HCN) in the left ventricles (LV) is linked to hypertrophied hearts and abnormal myocardium automaticity. Given that ivabradine (IVA) has emerging pleiotropic effects, in addition to the widely known bradycardic response, this study evaluated if IVA treatment could repair the autonomic control and cardiac damages in malnourished rats. AIM Assess the impact of IVA on tonic cardiovascular autonomic control and its relationship with hemodynamics regulation, LV inflammation, and HCN gene expression in post-weaning protein malnutrition condition. MAIN METHODS After weaning, male rats were divided into control (CG; 22 % protein) and malnourished (MG; 6 % protein) groups. At 35 days, groups were subdivided into CG-PBS, CG-IVA, MG-PBS and MG-IVA (PBS 1 ml/kg or IVA 1 mg/kg) received during 8 days. We performed jugular vein cannulation and electrode implant for drug delivery and ECG registration to assess tonic cardiovascular autonomic control; femoral cannulation for blood pressure (BP) and heart rate (HR) assessment; and LV collection to evaluate ventricular remodeling and HCN gene expression investigation. KEY FINDINGS Malnutrition induced BP and HR increases, sympathetic system dominance, and LV remodeling without affecting HCN gene expression. IVA reversed the cardiovascular autonomic imbalance; prevented hypertension and tachycardia; and inhibited the LV inflammatory process and fiber thickening caused by malnutrition. SIGNIFICANCE Our findings suggest that ivabradine protects against malnutrition-mediated cardiovascular damage. Moreover, our results propose these effects were not attributed to HCN expression changes, but rather to IVA pleiotropic effects on autonomic control and inflammation.
Collapse
Affiliation(s)
- Mariana Reis Guedes
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Sylvana Izaura Salyba Rendeiro de Noronha
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Máira Tereza Talma Chírico
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Gabriela Dias Carvalho da Costa
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Thalles de Freitas Castro
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Rory Cristiane Fortes de Brito
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Lucas Gabriel Vieira
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Thayane Oliveira Reis
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Marcelo Carlos Ribeiro
- Statistics Department, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Alexandre Barbosa Reis
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Cláudia Martins Carneiro
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Frank Silva Bezerra
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Nicola Montano
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
| | - Valdo José Dias da Silva
- Department of Biochemistry, Pharmacology and Physiology, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil; Graduate Program in Physiological Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil.
| | - Rodrigo Cunha Alvim de Menezes
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Deoclécio Alves Chianca-Jr
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Fernanda Cacilda Dos Santos Silva
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| |
Collapse
|
3
|
Hennis K, Piantoni C, Biel M, Fenske S, Wahl-Schott C. Pacemaker Channels and the Chronotropic Response in Health and Disease. Circ Res 2024; 134:1348-1378. [PMID: 38723033 PMCID: PMC11081487 DOI: 10.1161/circresaha.123.323250] [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
Loss or dysregulation of the normally precise control of heart rate via the autonomic nervous system plays a critical role during the development and progression of cardiovascular disease-including ischemic heart disease, heart failure, and arrhythmias. While the clinical significance of regulating changes in heart rate, known as the chronotropic effect, is undeniable, the mechanisms controlling these changes remain not fully understood. Heart rate acceleration and deceleration are mediated by increasing or decreasing the spontaneous firing rate of pacemaker cells in the sinoatrial node. During the transition from rest to activity, sympathetic neurons stimulate these cells by activating β-adrenergic receptors and increasing intracellular cyclic adenosine monophosphate. The same signal transduction pathway is targeted by positive chronotropic drugs such as norepinephrine and dobutamine, which are used in the treatment of cardiogenic shock and severe heart failure. The cyclic adenosine monophosphate-sensitive hyperpolarization-activated current (If) in pacemaker cells is passed by hyperpolarization-activated cyclic nucleotide-gated cation channels and is critical for generating the autonomous heartbeat. In addition, this current has been suggested to play a central role in the chronotropic effect. Recent studies demonstrate that cyclic adenosine monophosphate-dependent regulation of HCN4 (hyperpolarization-activated cyclic nucleotide-gated cation channel isoform 4) acts to stabilize the heart rate, particularly during rapid rate transitions induced by the autonomic nervous system. The mechanism is based on creating a balance between firing and recently discovered nonfiring pacemaker cells in the sinoatrial node. In this way, hyperpolarization-activated cyclic nucleotide-gated cation channels may protect the heart from sinoatrial node dysfunction, secondary arrhythmia of the atria, and potentially fatal tachyarrhythmia of the ventricles. Here, we review the latest findings on sinoatrial node automaticity and discuss the physiological and pathophysiological role of HCN pacemaker channels in the chronotropic response and beyond.
Collapse
Affiliation(s)
- Konstantin Hennis
- Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center Munich, Walter Brendel Centre of Experimental Medicine, Faculty of Medicine (K.H., C.P., C.W.-S.), Ludwig-Maximilians-Universität München, Germany
| | - Chiara Piantoni
- Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center Munich, Walter Brendel Centre of Experimental Medicine, Faculty of Medicine (K.H., C.P., C.W.-S.), Ludwig-Maximilians-Universität München, Germany
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research (M.B., S.F.), Ludwig-Maximilians-Universität München, Germany
- German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Germany (M.B., S.F.)
| | - Stefanie Fenske
- Department of Pharmacy, Center for Drug Research (M.B., S.F.), Ludwig-Maximilians-Universität München, Germany
- German Centre for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Germany (M.B., S.F.)
| | - Christian Wahl-Schott
- Institute of Cardiovascular Physiology and Pathophysiology, Biomedical Center Munich, Walter Brendel Centre of Experimental Medicine, Faculty of Medicine (K.H., C.P., C.W.-S.), Ludwig-Maximilians-Universität München, Germany
| |
Collapse
|
4
|
Harde E, Hierl M, Weber M, Waiz D, Wyler R, Wach JY, Haab R, Gundlfinger A, He W, Schnider P, Paina M, Rolland JF, Greiter-Wilke A, Gasser R, Reutlinger M, Dupont A, Roberts S, O'Connor EC, Bartels B, Hall BJ. Selective and brain-penetrant HCN1 inhibitors reveal links between synaptic integration, cortical function, and working memory. Cell Chem Biol 2024; 31:577-592.e23. [PMID: 38042151 DOI: 10.1016/j.chembiol.2023.11.004] [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: 06/29/2023] [Revised: 09/28/2023] [Accepted: 11/07/2023] [Indexed: 12/04/2023]
Abstract
Hyperpolarization-activated and cyclic-nucleotide-gated 1 (HCN1) ion channels are proposed to be critical for cognitive function through regulation of synaptic integration. However, resolving the precise role of HCN1 in neurophysiology and exploiting its therapeutic potential has been hampered by minimally selective antagonists with poor potency and limited in vivo efficiency. Using automated electrophysiology in a small-molecule library screen and chemical optimization, we identified a primary carboxamide series of potent and selective HCN1 inhibitors with a distinct mode of action. In cognition-relevant brain circuits, selective inhibition of native HCN1 produced on-target effects, including enhanced excitatory postsynaptic potential summation, while administration of a selective HCN1 inhibitor to rats recovered decrement working memory. Unlike prior non-selective HCN antagonists, selective HCN1 inhibition did not alter cardiac physiology in human atrial cardiomyocytes or in rats. Collectively, selective HCN1 inhibitors described herein unmask HCN1 as a potential target for the treatment of cognitive dysfunction in brain disorders.
Collapse
Affiliation(s)
- Eva Harde
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
| | - Markus Hierl
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Michael Weber
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - David Waiz
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Roger Wyler
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Jean-Yves Wach
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Rachel Haab
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Anja Gundlfinger
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Weiping He
- WuXi AppTec (Wuhan) Co., Ltd, 666 Gaoxin Road, Wuhan East Lake High-Tech Development Zone, Wuhan, Huibei, China
| | - Patrick Schnider
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | | | | | - Andrea Greiter-Wilke
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Rodolfo Gasser
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Michael Reutlinger
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Amanda Dupont
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Sonia Roberts
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Eoin C O'Connor
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
| | - Björn Bartels
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
| | - Benjamin J Hall
- Roche Pharma Research and Early Development, Neuroscience and Rare Diseases Discovery and Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| |
Collapse
|
5
|
Pettini F, Spiga O, Furini S, Fusi F. Electrophysiology, molecular modelling, and functional analysis of the effects of dietary quercetin and flavonoid analogues on K ir6.1 channels in rat stomach fundus smooth muscle. Biochem Pharmacol 2024; 220:115969. [PMID: 38086489 DOI: 10.1016/j.bcp.2023.115969] [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: 11/01/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/17/2023]
Abstract
Flavonoids, ubiquitously distributed in the plant world, are regularly ingested with diets rich in fruit, vegetables, wine, and tea. During digestion, they are partially absorbed in the stomach. The present work aimed to assess the in vitro effects of quercetin and ten structurally related flavonoids on the rat gastric fundus smooth muscle, focussing on ATP-dependent K+ (Kir6.1) channels, which play a central role in the regulation of resting membrane potential, membrane excitability and, consequently, of gastric motility. Whole-cell currents through Kir6.1 channels (IKir6.1) were recorded with the patch-clamp technique and the mechanical activity of gastric fundus smooth muscle strips was studied under isometric conditions. Galangin ≈ tamarixetin > quercetin > kaempferol > isorhamnetin ≈ luteolin ≈ fisetin > (±)-taxifolin inhibited pinacidil-evoked, glibenclamide-sensitive IKir6.1 in a concentration-dependent manner. Morin, rutin, and myricetin were ineffective. The steric hindrance of the molecule and the number and position of hydroxyl groups on the B ring played an important role in the activity of the molecule. Molecular docking simulations revealed a possible binding site for flavonoids in the C-terminal domain of the Kir6.1 channel subunit SUR2B, in a flexible loop formed by residues 251 to 254 of chains C and D. Galangin and tamarixetin, but not rutin relaxed both high K+- and carbachol-induced contraction of fundus strips in a concentration-dependent manner. Furthermore, both flavonoids shifted to the right the concentration-relaxation curves to either pinacidil or L-cysteine constructed in strips pre-contracted by high K+, rutin being ineffective. In conclusion, IKir6.1 inhibition exerted by dietary flavonoids might counterbalance their myorelaxant activity, affect gastric accommodation or, at least, some stages of digestion.
Collapse
Affiliation(s)
- Francesco Pettini
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro 2, 53100 Siena, Italy.
| | - Ottavia Spiga
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro 2, 53100 Siena, Italy.
| | - Simone Furini
- Department of Electrical, Electronic and Information Engineering ″Guglielmo Marconi", University of Bologna, via dell'Università 50, 47521, Cesena, (FC), Italy.
| | - Fabio Fusi
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università di Siena, Via A. Moro 2, 53100 Siena, Italy.
| |
Collapse
|
6
|
Mujaddadi A, Zaki S, M Noohu M, Naqvi IH, Veqar Z. Predictors of Cardiac Autonomic Dysfunction in Obesity-Related Hypertension. High Blood Press Cardiovasc Prev 2024; 31:77-91. [PMID: 38345729 DOI: 10.1007/s40292-024-00623-7] [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: 09/20/2023] [Accepted: 01/04/2024] [Indexed: 03/12/2024] Open
Abstract
INTRODUCTION Cardiac Autonomic Dysfunction (CAD) is an overlooked cardiovascular risk factor in individuals with obesity-related hypertension. Despite its clinical significance, there is a notable lack of clarity regarding the pathophysiological correlates involved in its onset and progression. AIM The present study aimed to identify potential predictors of CAD in obesity-related hypertension. METHODS A total of 72 participants (34 men and 38 women) were enrolled. Comprehensive evaluations were conducted, including cardiac autonomic function assessments, body composition estimation and biochemical analysis. Participants were categorized as CAD-positive or CAD-negative based on Ewing's criteria for autonomic dysfunction. Univariate logistic regression analysis was performed to identify potential predictors for CAD. Multivariate logistic regression models were further constructed by adjusting clinically relevant covariates to identify independent predictors of CAD. RESULTS Multivariate logistic regression analysis revealed that resting heart rate (HRrest), (odds ratio, confidence interval: 0.85, 0.78-0.93; p = 0.001) and percentage body fat (BF%), (odds ratio, confidence interval: 0.78, 0.64-0.96; p = 0.018) were significant independent predictors of CAD. Receiver Operating Characteristic curve analysis depicted optimal cut-off values for HRrest and BF% as > 74.1 bpm and > 33.6%, respectively. Multicolinearity analysis showed variance inflation factors (VIF) below the cautionary threshold of 3. CONCLUSIONS The HRrest and BF% emerged as significant independent predictors of CAD in obesity-related hypertension. Therapeutic strategies should target HRrest < 74.1 bpm and BF% < 33.6% to mitigate CAD risk in this population. Future trials are required to establish causal relationships and may consider additional confounding variables in obesity-related hypertension.
Collapse
Affiliation(s)
- Aqsa Mujaddadi
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, 110025, India
| | - Saima Zaki
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, 110025, India
| | - Majumi M Noohu
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, 110025, India
| | - Irshad Husain Naqvi
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, 110025, India
- Dr. M.A. Ansari Health Centre, Jamia Millia Islamia (A Central University), New Delhi, 110025, India
| | - Zubia Veqar
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia (A Central University), New Delhi, 110025, India.
| |
Collapse
|
7
|
Boerhout C, Feenstra R, van de Hoef T, Piek J, Beijk M. Pharmacotherapy in patients with vasomotor disorders. IJC HEART & VASCULATURE 2023; 48:101267. [PMID: 37727753 PMCID: PMC10505589 DOI: 10.1016/j.ijcha.2023.101267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/23/2023] [Accepted: 09/03/2023] [Indexed: 09/21/2023]
Abstract
Background Anginal symptoms in patients with non-obstructive coronary artery disease are frequently related to vasomotor disorders of the coronary circulation. Although frequently overlooked, a distinct diagnosis of different vasomotor disorders can be made by intracoronary function testing. Early detection and treatment seems beneficial, but little evidence is available for the medical treatment of these disorders. Nevertheless, there are several pharmacotherapeutic options available to treat these patients and improve quality of life. Methods & findings We performed an extensive yet non-systematic literature search to explore available pharmacotherapeutic strategies for addressing vasomotor disorders in individuals experiencing angina and non-obstructive coronary artery disease. This article presents a comprehensive overview of therapeutic possibilities for patients exhibiting abnormal vasoconstriction (such as spasm) and abnormal vasodilation (like coronary microvascular dysfunction). Conclusion Treatment of vasomotor disorders can be very challenging, but a general treatment algorithm based on the existing evidence and the best available current practice is feasible.
Collapse
Affiliation(s)
| | | | - T.P. van de Hoef
- Heart Center, Amsterdam UMC, Amsterdam, the Netherlands
- Department of Cardiology, University Medical Centre Utrecht, Utrecht, the Netherlands
| | - J.J. Piek
- Heart Center, Amsterdam UMC, Amsterdam, the Netherlands
| | - M.A.M. Beijk
- Heart Center, Amsterdam UMC, Amsterdam, the Netherlands
| |
Collapse
|
8
|
Ricci E, Bartolucci C, Severi S. The virtual sinoatrial node: What did computational models tell us about cardiac pacemaking? PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 177:55-79. [PMID: 36374743 DOI: 10.1016/j.pbiomolbio.2022.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022]
Abstract
Since its discovery, the sinoatrial node (SAN) has represented a fascinating and complex matter of research. Despite over a century of discoveries, a full comprehension of pacemaking has still to be achieved. Experiments often produced conflicting evidence that was used either in support or against alternative theories, originating intense debates. In this context, mathematical descriptions of the phenomena underlying the heartbeat have grown in importance in the last decades since they helped in gaining insights where experimental evaluation could not reach. This review presents the most updated SAN computational models and discusses their contribution to our understanding of cardiac pacemaking. Electrophysiological, structural and pathological aspects - as well as the autonomic control over the SAN - are taken into consideration to reach a holistic view of SAN activity.
Collapse
Affiliation(s)
- Eugenio Ricci
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena (FC), Italy
| | - Chiara Bartolucci
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena (FC), Italy
| | - Stefano Severi
- Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, Cesena (FC), Italy.
| |
Collapse
|
9
|
Peters CH, Rickert C, Morotti S, Grandi E, Aronow KA, Beam KG, Proenza C. The funny current If is essential for the fight-or-flight response in cardiac pacemaker cells. J Gen Physiol 2022; 154:e202213193. [PMID: 36305844 PMCID: PMC9812006 DOI: 10.1085/jgp.202213193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/22/2022] [Accepted: 10/04/2022] [Indexed: 01/07/2023] Open
Abstract
The sympathetic nervous system fight-or-flight response is characterized by a rapid increase in heart rate, which is mediated by an increase in the spontaneous action potential (AP) firing rate of pacemaker cells in the sinoatrial node. Sympathetic neurons stimulate sinoatrial myocytes (SAMs) by activating β adrenergic receptors (βARs) and increasing cAMP. The funny current (If) is among the cAMP-sensitive currents in SAMs. If is critical for pacemaker activity, however, its role in the fight-or-flight response remains controversial. In this study, we used AP waveform analysis, machine learning, and dynamic clamp experiments in acutely isolated SAMs from mice to quantitatively define the AP waveform changes and role of If in the fight-or-flight increase in AP firing rate. We found that while βAR stimulation significantly altered nearly all AP waveform parameters, the increase in firing rate was only correlated with changes in a subset of parameters (diastolic duration, late AP duration, and diastolic depolarization rate). Dynamic clamp injection of the βAR-sensitive component of If showed that it accounts for ∼41% of the fight-or-flight increase in AP firing rate and 60% of the decrease in the interval between APs. Thus, If is an essential contributor to the fight-or-flight increase in heart rate.
Collapse
Affiliation(s)
- Colin H. Peters
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Christian Rickert
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, School of Medicine, Davis, CA
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, School of Medicine, Davis, CA
| | | | - Kurt G. Beam
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Catherine Proenza
- Department of Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO
| |
Collapse
|
10
|
Li J, Wiesinger A, Fokkert L, Boukens BJ, Verkerk AO, Christoffels VM, Boink GJ, Devalla HD. Molecular and electrophysiological evaluation of human cardiomyocyte subtypes to facilitate generation of composite cardiac models. J Tissue Eng 2022; 13:20417314221127908. [PMID: 36277058 PMCID: PMC9583221 DOI: 10.1177/20417314221127908] [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: 03/02/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022] Open
Abstract
Paucity of physiologically relevant cardiac models has limited the widespread application of human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes in drug development. Here, we performed comprehensive characterization of hiPSC-derived cardiomyocyte subtypes from 2D and 3D cultures and established a novel 3D model to study impulse initiation and propagation. Directed differentiation approaches were used to generate sinoatrial nodal (SANCM), atrial (ACM) and ventricular cardiomyocytes (VCM). Single cell RNA sequencing established that the protocols yield distinct cell populations in line with expected identities, which was also confirmed by electrophysiological characterization. In 3D EHT cultures of all subtypes, we observed prominent expression of stretch-responsive genes such as NPPA. Response to rate modulating drugs noradrenaline, carbachol and ivabradine were comparable in single cells and EHTs. Differences in the speed of impulse propagation between the subtypes were more pronounced in EHTs compared with 2D monolayers owing to a progressive increase in conduction velocities in atrial and ventricular cardiomyocytes, in line with a more mature phenotype. In a novel binary EHT model of pacemaker-atrial interface, the SANCM end of the tissue consistently paced the EHTs under baseline conditions, which was inhibited by ivabradine. Taken together, our data provide comprehensive insights into molecular and electrophysiological properties of hiPSC-derived cardiomyocyte subtypes, facilitating the creation of next generation composite cardiac models for drug discovery, disease modeling and cell-based regenerative therapies.
Collapse
Affiliation(s)
- Jiuru Li
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Alexandra Wiesinger
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Lianne Fokkert
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Bastiaan J. Boukens
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Arie O. Verkerk
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands,Department of Experimental Cardiology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Vincent M. Christoffels
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Gerard J.J. Boink
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands,Department of Cardiology, Amsterdam
University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands
| | - Harsha D. Devalla
- Department of Medical Biology,
Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The
Netherlands,Harsha D Devalla, Department of Medical
Biology, Amsterdam University Medical Centers, University of Amsterdam,
Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
| |
Collapse
|
11
|
Wiesinger A, Li J, Fokkert L, Bakker P, Verkerk AO, Christoffels VM, Boink GJJ, Devalla HD. A single cell transcriptional roadmap of human pacemaker cell differentiation. eLife 2022; 11:76781. [PMID: 36217819 PMCID: PMC9553210 DOI: 10.7554/elife.76781] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 08/16/2022] [Indexed: 12/26/2022] Open
Abstract
Each heartbeat is triggered by the sinoatrial node (SAN), the primary pacemaker of the heart. Studies in animal models have revealed that pacemaker cells share a common progenitor with the (pro)epicardium, and that the pacemaker cardiomyocytes further diversify into ‘transitional’, ‘tail’, and ‘head’ subtypes. However, the underlying molecular mechanisms, especially of human pacemaker cell development, are poorly understood. Here, we performed single cell RNA sequencing (scRNA-seq) and trajectory inference on human induced pluripotent stem cells (hiPSCs) differentiating to SAN-like cardiomyocytes (SANCMs) to construct a roadmap of transcriptional changes and lineage decisions. In differentiated SANCM, we identified distinct clusters that closely resemble different subpopulations of the in vivo SAN. Moreover, the presence of a side population of proepicardial cells suggested their shared ontogeny with SANCM, as also reported in vivo. Our results demonstrate that the divergence of SANCM and proepicardial lineages is determined by WNT signaling. Furthermore, we uncovered roles for TGFβ and WNT signaling in the branching of transitional and head SANCM subtypes, respectively. These findings provide new insights into the molecular processes involved in human pacemaker cell differentiation, opening new avenues for complex disease modeling in vitro and inform approaches for cell therapy-based regeneration of the SAN.
Collapse
Affiliation(s)
- Alexandra Wiesinger
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Jiuru Li
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Lianne Fokkert
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Priscilla Bakker
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Arie O Verkerk
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Department of Experimental Cardiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Vincent M Christoffels
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Gerard J J Boink
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Department of Cardiology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Harsha D Devalla
- Department of Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| |
Collapse
|
12
|
Liu J, Kasuya G, Zempo B, Nakajo K. Two HCN4 Channels Play Functional Roles in the Zebrafish Heart. Front Physiol 2022; 13:901571. [PMID: 35846012 PMCID: PMC9281569 DOI: 10.3389/fphys.2022.901571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
The HCN4 channel is essential for heart rate regulation in vertebrates by generating pacemaker potentials in the sinoatrial node. HCN4 channel abnormality may cause bradycardia and sick sinus syndrome, making it an important target for clinical research and drug discovery. The zebrafish is a popular animal model for cardiovascular research. They are potentially suitable for studying inherited heart diseases, including cardiac arrhythmia. However, it has not been determined how similar the ion channels that underlie cardiac automaticity are in zebrafish and humans. In the case of HCN4, humans have one gene, whereas zebrafish have two ortholog genes (DrHCN4 and DrHCN4L; ‘Dr’ referring to Danio rerio). However, it is not known whether the two HCN4 channels have different physiological functions and roles in heart rate regulation. In this study, we characterized the biophysical properties of the two zebrafish HCN4 channels in Xenopus oocytes and compared them to those of the human HCN4 channel. We found that they showed different gating properties: DrHCN4L currents showed faster activation kinetics and a more positively shifted G-V curve than did DrHCN4 and human HCN4 currents. We made chimeric channels of DrHCN4 and DrHCN4L and found that cytoplasmic domains were determinants for the faster activation and the positively shifted G-V relationship in DrHCN4L. The use of a dominant-negative HCN4 mutant confirmed that DrHCN4 and DrHCN4L can form a heteromultimeric channel in Xenopus oocytes. Next, we confirmed that both are sensitive to common HCN channel inhibitors/blockers including Cs+, ivabradine, and ZD7288. These HCN inhibitors successfully lowered zebrafish heart rate during early embryonic stages. Finally, we knocked down the HCN4 genes using antisense morpholino and found that knocking down either or both of the HCN4 channels caused a temporal decrease in heart rate and tended to cause pericardial edema. These findings suggest that both DrHCN4 and DrHCN4L play a significant role in zebrafish heart rate regulation.
Collapse
|
13
|
Hackl B, Lukacs P, Ebner J, Pesti K, Haechl N, Földi MC, Lilliu E, Schicker K, Kubista H, Stary-Weinzinger A, Hilber K, Mike A, Todt H, Koenig X. The Bradycardic Agent Ivabradine Acts as an Atypical Inhibitor of Voltage-Gated Sodium Channels. Front Pharmacol 2022; 13:809802. [PMID: 35586063 PMCID: PMC9108390 DOI: 10.3389/fphar.2022.809802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/24/2022] [Indexed: 12/19/2022] Open
Abstract
Background and purpose: Ivabradine is clinically administered to lower the heart rate, proposedly by inhibiting hyperpolarization-activated cyclic nucleotide-gated cation channels in the sinoatrial node. Recent evidence suggests that voltage-gated sodium channels (VGSC) are inhibited within the same concentration range. VGSCs are expressed within the sinoatrial node and throughout the conduction system of the heart. A block of these channels thus likely contributes to the established and newly raised clinical indications of ivabradine. We, therefore, investigated the pharmacological action of ivabradine on VGSCs in sufficient detail in order to gain a better understanding of the pro- and anti-arrhythmic effects associated with the administration of this drug. Experimental Approach: Ivabradine was tested on VGSCs in native cardiomyocytes isolated from mouse ventricles and the His-Purkinje system and on human Nav1.5 in a heterologous expression system. We investigated the mechanism of channel inhibition by determining its voltage-, frequency-, state-, and temperature-dependence, complemented by a molecular drug docking to the recent Nav1.5 cryoEM structure. Automated patch-clamp experiments were used to investigate ivabradine-mediated changes in Nav1.5 inactivation parameters and inhibition of different VGSC isoforms. Key results: Ivabradine inhibited VGSCs in a voltage- and frequency-dependent manner, but did not alter voltage-dependence of activation and fast inactivation, nor recovery from fast inactivation. Cardiac (Nav1.5), neuronal (Nav1.2), and skeletal muscle (Nav1.4) VGSC isoforms were inhibited by ivabradine within the same concentration range, as were sodium currents in native cardiomyocytes isolated from the ventricles and the His-Purkinje system. Molecular drug docking suggested an interaction of ivabradine with the classical local anesthetic binding site. Conclusion and Implications: Ivabradine acts as an atypical inhibitor of VGSCs. Inhibition of VGSCs likely contributes to the heart rate lowering effect of ivabradine, in particular at higher stimulation frequencies and depolarized membrane potentials, and to the observed slowing of intra-cardiac conduction. Inhibition of VGSCs in native cardiomyocytes and across channel isoforms may provide a potential basis for the anti-arrhythmic potential as observed upon administration of ivabradine.
Collapse
Affiliation(s)
- Benjamin Hackl
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Peter Lukacs
- ELKH, Plant Protection Institute, Centre for Agricultural Research, Martonvásár, Hungary
| | - Janine Ebner
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Krisztina Pesti
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
- Semmelweis University, School of Ph.D. Studies, Budapest, Hungary
| | - Nicholas Haechl
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Mátyás C Földi
- ELKH, Plant Protection Institute, Centre for Agricultural Research, Martonvásár, Hungary
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Elena Lilliu
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Klaus Schicker
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Helmut Kubista
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | | | - Karlheinz Hilber
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Arpad Mike
- ELKH, Plant Protection Institute, Centre for Agricultural Research, Martonvásár, Hungary
- Department of Biochemistry, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Hannes Todt
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
| | - Xaver Koenig
- Department of Neurophysiology and Neuropharmacology, Medical University of Vienna, Vienna, Austria
- *Correspondence: Xaver Koenig,
| |
Collapse
|
14
|
Frequency-Dependent Properties of the Hyperpolarization-Activated Cation Current, I f, in Adult Mouse Heart Primary Pacemaker Myocytes. Int J Mol Sci 2022; 23:ijms23084299. [PMID: 35457119 PMCID: PMC9024942 DOI: 10.3390/ijms23084299] [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] [Received: 02/28/2022] [Revised: 04/05/2022] [Accepted: 04/11/2022] [Indexed: 02/04/2023] Open
Abstract
A number of distinct electrophysiological mechanisms that modulate the myogenic spontaneous pacemaker activity in the sinoatrial node (SAN) of the mammalian heart have been investigated extensively. There is agreement that several (3 or 4) different transmembrane ionic current changes (referred to as the voltage clock) are involved; and that the resulting net current interacts with direct and indirect effects of changes in intracellular Ca2+ (the calcium clock). However, significant uncertainties, and important knowledge gaps, remain concerning the functional roles in SAN spontaneous pacing of many of the individual ion channel- or exchanger-mediated transmembrane current changes. We report results from patch clamp studies and mathematical modeling of the hyperpolarization-activated current, If, in the generation/modulation of the diastolic depolarization, or pacemaker potential, produced by individual myocytes that were enzymatically isolated from the adult mouse sinoatrial node (SAN). Amphotericin-mediated patch microelectrode recordings at 35 °C were made under control conditions and in the presence of 5 or 10 nM isoproterenol (ISO). These sets of results were complemented and integrated with mathematical modeling of the current changes that take place in the range of membrane potentials (−70 to −50 mV), which corresponds to the ‘pacemaker depolarization’ in the adult mouse SAN. Our results reveal a very small, but functionally important, approximately steady-state or time-independent current generated by residual activation of If channels that are expressed in these pacemaker myocytes. Recordings of the pacemaker depolarization and action potential, combined with measurements of changes in If, and the well-known increases in the L-type Ca2+ current, ICaL, demonstrated that ICaL activation, is essential for myogenic pacing. Moreover, after being enhanced (approximately 3-fold) by 5 or 10 nM ISO, ICaL contributes significantly to the positive chronotropic effect. Our mathematical model has been developed in an attempt to better understand the underlying mechanisms for the pacemaker depolarization and action potential in adult mouse SAN myocytes. After being updated with our new experimental data describing If, our simulations reveal a novel functional component of If in adult mouse SAN. Computational work carried out with this model also confirms that in the presence of ISO the residual activation of If and opening of ICaL channels combine to generate a net current change during the slow diastolic depolarization phase that is essential for the observed accelerated pacemaking rate of these SAN myocytes.
Collapse
|
15
|
Ammer G, Vieira RM, Fendl S, Borst A. Anatomical distribution and functional roles of electrical synapses in Drosophila. Curr Biol 2022; 32:2022-2036.e4. [DOI: 10.1016/j.cub.2022.03.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 02/16/2022] [Accepted: 03/14/2022] [Indexed: 10/18/2022]
|
16
|
Piantoni C, Paina M, Molla D, Liu S, Bertoli G, Jiang H, Wang Y, Wang Y, Wang Y, DiFrancesco D, Barbuti A, Bucchi A, Baruscotti M. Chinese natural compound decreases pacemaking of rabbit cardiac sinoatrial cells by targeting second messenger regulation of f-channels. eLife 2022; 11:75119. [PMID: 35315774 PMCID: PMC8940175 DOI: 10.7554/elife.75119] [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: 10/29/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Tongmai Yangxin (TMYX) is a complex compound of the Traditional Chinese Medicine (TCM) used to treat several cardiac rhythm disorders; however, no information regarding its mechanism of action is available. In this study we provide a detailed characterization of the effects of TMYX on the electrical activity of pacemaker cells and unravel its mechanism of action. Single-cell electrophysiology revealed that TMYX elicits a reversible and dose-dependent (2/6 mg/ml) slowing of spontaneous action potentials rate (−20.8/–50.2%) by a selective reduction of the diastolic phase (−50.1/–76.0%). This action is mediated by a negative shift of the If activation curve (−6.7/–11.9 mV) and is caused by a reduction of the cyclic adenosine monophosphate (cAMP)-induced stimulation of pacemaker channels. We provide evidence that TMYX acts by directly antagonizing the cAMP-induced allosteric modulation of the pacemaker channels. Noticeably, this mechanism functionally resembles the pharmacological actions of muscarinic stimulation or β-blockers, but it does not require generalized changes in cytoplasmic cAMP levels thus ensuring a selective action on rate. In agreement with a competitive inhibition mechanism, TMYX exerts its maximal antagonistic action at submaximal cAMP concentrations and then progressively becomes less effective thus ensuring a full contribution of If to pacemaker rate during high metabolic demand and sympathetic stimulation.
Collapse
Affiliation(s)
- Chiara Piantoni
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - David Molla
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Sheng Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Giorgia Bertoli
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Hongmei Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Yanyan Wang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi Wang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Traditional Chinese Medicine Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Dario DiFrancesco
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| |
Collapse
|
17
|
The Inhibition of the Small-Conductance Ca2+-Activated Potassium Channels Decreases the Sinus Node Pacemaking during Beta-Adrenergic Activation. Pharmaceuticals (Basel) 2022; 15:ph15030313. [PMID: 35337111 PMCID: PMC8948633 DOI: 10.3390/ph15030313] [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: 10/31/2021] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 11/17/2022] Open
Abstract
Sinus pacemaking is based on tight cooperation of intracellular Ca2+ handling and surface membrane ion channels. An important player of this synergistic crosstalk could be the small-conductance Ca2+-activated K+-channel (ISK) that could contribute to the sinoatrial node (SAN) pacemaking driven by the intracellular Ca2+ changes under normal conditions and beta-adrenergic activation, however, the exact role is not fully clarified. SK2 channel expression was verified by immunoblot technique in rabbit SAN cells. Ionic currents and action potentials were measured by patch-clamp technique. The ECG R-R intervals were obtained by Langendorff-perfusion method on a rabbit heart. Apamin, a selective inhibitor of SK channels, was used during the experiments. Patch-clamp experiments revealed an apamin-sensitive current. When 100 nM apamin was applied, we found no change in the action potential nor in the ECG R-R interval. In experiments where isoproterenol was employed, apamin increased the cycle length of the SAN action potentials and enhanced the ECG R-R interval. Apamin did not amplify the cycle length variability or ECG R-R interval variability. Our data indicate that ISK has no role under normal condition, however, it moderately contributes to the SAN automaticity under beta-adrenergic activation.
Collapse
|
18
|
Bertero E, Heusch G, Münzel T, Maack C. A pathophysiological compass to personalize antianginal drug treatment. Nat Rev Cardiol 2021; 18:838-852. [PMID: 34234310 DOI: 10.1038/s41569-021-00573-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/24/2021] [Indexed: 02/06/2023]
Abstract
Myocardial ischaemia results from coronary macrovascular or microvascular dysfunction compromising the supply of oxygen and nutrients to the myocardium. The underlying pathophysiological processes are manifold and encompass atherosclerosis of epicardial coronary arteries, vasospasm of large or small vessels and microvascular dysfunction - the clinical relevance of which is increasingly being appreciated. Myocardial ischaemia can have a broad spectrum of clinical manifestations, together denoted as chronic coronary syndromes. The most common antianginal medications relieve symptoms by eliciting coronary vasodilatation and modulating the determinants of myocardial oxygen consumption, that is, heart rate, myocardial wall stress and ventricular contractility. In addition, cardiac substrate metabolism can be altered to alleviate ischaemia by modulating the efficiency of myocardial oxygen use. Although a universal agreement exists on the prognostic importance of lifestyle interventions and event prevention with aspirin and statin therapy, the optimal antianginal treatment for patients with chronic coronary syndromes is less well defined. The 2019 guidelines of the ESC recommend a personalized approach, in which antianginal medications are tailored towards an individual patient's comorbidities and haemodynamic profile. Although no antianginal medication improves survival, their efficacy for reducing symptoms profoundly depends on the underlying mechanism of the angina. In this Review, we provide clinicians with a rationale for when to use which compound or combination of drugs on the basis of the pathophysiology of the angina and the mode of action of antianginal medications.
Collapse
Affiliation(s)
- Edoardo Bertero
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Gerd Heusch
- Institute for Pathophysiology, West German Heart and Vascular Center, University of Duisburg-Essen, Essen, Germany
| | - Thomas Münzel
- Department of Cardiology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
- German Center for Cardiovascular Research (DZHK), Partner site Rhine-Main, Mainz, Germany.
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany.
- Department of Internal Medicine 1, University Clinic Würzburg, Würzburg, Germany.
| |
Collapse
|
19
|
Rodríguez-Angulo HO, Colombet-Naranjo D, Maza MC, Poveda C, Herreros-Cabello A, Mendoza I, Perera JC, Goyo JD, Gironès N, Fresno M. Molecular Remodeling of Cardiac Sinus Node Associated with Acute Chagas Disease Myocarditis. Microorganisms 2021; 9:microorganisms9112208. [PMID: 34835334 PMCID: PMC8620628 DOI: 10.3390/microorganisms9112208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 01/04/2023] Open
Abstract
Chagas disease principally affects Latin-American people, but it currently has worldwide distribution due to migration. Death among those with Chagas disease can occur suddenly and without warning, even in those who may not have evidence of clinical or structural cardiac disease and who are younger than 60 years old. HCN4 channels, one of the principal elements responsible for pacemaker currents, are associated with cardiac fetal reprogramming and supraventricular and ventricular arrhythmias, but their role in chagasic arrhythmias is not clear. We found that a single-dose administration of ivabradine, which blocks HCN4, caused QTc and QRS enlargement and an increase in P-wave amplitude and was associated with ventricular and supraventricular arrhythmias in mice challenged with isoproterenol, a chronotropic/ionotropic positive agent. Continuous treatment with ivabradine did not alter the QTc interval, but P-wave morphology was deeply modified, generating supraventricular arrhythmias. In addition, we found that repolarization parameters improved with ivabradine treatment. These effects could have been caused by the high HCN4 expression observed in auricular and ventricular tissue in infected mice. Thus, we suggest, for the first time, that molecular remodeling by overexpression of HCN4 channels may be related to supraventricular arrhythmias in acute Chagas disease, causing ivabradine over-response. Thus, ivabradine treatment should be administered with caution, while HCN4 overexpression may be an indicator of heart failure and/or sudden death risk.
Collapse
Affiliation(s)
- Héctor O. Rodríguez-Angulo
- Instituto Venezolano de Investigaciones Científicas, Caracas 1020A, Venezuela; (H.O.R.A.); (D.C.-N.)
- Unidad de Biología Celular, Departamento de Ciencias Morfológicas, Programa de Medicina, Facultad de Ciencias de la vida, Universidad Centroccidental Lisandro Alvarado, Barquisimeto 3001, Venezuela; (J.C.P.); (J.D.G.)
| | - Diana Colombet-Naranjo
- Instituto Venezolano de Investigaciones Científicas, Caracas 1020A, Venezuela; (H.O.R.A.); (D.C.-N.)
| | - María C. Maza
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (M.C.M.); (C.P.); (A.-H.C.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain
| | - Cristina Poveda
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (M.C.M.); (C.P.); (A.-H.C.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain
| | - Alfonso Herreros-Cabello
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (M.C.M.); (C.P.); (A.-H.C.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain
| | - Iván Mendoza
- Instituto de Medicina Tropical, Universidad Central de Venezuela, Caracas 1060, Venezuela;
| | - Juan C. Perera
- Unidad de Biología Celular, Departamento de Ciencias Morfológicas, Programa de Medicina, Facultad de Ciencias de la vida, Universidad Centroccidental Lisandro Alvarado, Barquisimeto 3001, Venezuela; (J.C.P.); (J.D.G.)
| | - Juan D. Goyo
- Unidad de Biología Celular, Departamento de Ciencias Morfológicas, Programa de Medicina, Facultad de Ciencias de la vida, Universidad Centroccidental Lisandro Alvarado, Barquisimeto 3001, Venezuela; (J.C.P.); (J.D.G.)
| | - Núria Gironès
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (M.C.M.); (C.P.); (A.-H.C.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, 28009 Madrid, Spain
- Correspondence: (N.G.); (M.F.)
| | - Manuel Fresno
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (M.C.M.); (C.P.); (A.-H.C.)
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, 28049 Madrid, Spain
- Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, 28009 Madrid, Spain
- Correspondence: (N.G.); (M.F.)
| |
Collapse
|
20
|
Bai X, Wang K, Boyett MR, Hancox JC, Zhang H. The Functional Role of Hyperpolarization Activated Current ( I f) on Cardiac Pacemaking in Human vs. in the Rabbit Sinoatrial Node: A Simulation and Theoretical Study. Front Physiol 2021; 12:582037. [PMID: 34489716 PMCID: PMC8417414 DOI: 10.3389/fphys.2021.582037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 07/23/2021] [Indexed: 01/01/2023] Open
Abstract
The cardiac hyperpolarization-activated “funny” current (If), which contributes to sinoatrial node (SAN) pacemaking, has a more negative half-maximal activation voltage and smaller fully-activated macroscopic conductance in human than in rabbit SAN cells. The consequences of these differences for the relative roles of If in the two species, and for their responses to the specific bradycardic agent ivabradine at clinical doses have not been systematically explored. This study aims to address these issues, through incorporating rabbit and human If formulations developed by Fabbri et al. into the Severi et al. model of rabbit SAN cells. A theory was developed to correlate the effect of If reduction with the total inward depolarising current (Itotal) during diastolic depolarization. Replacing the rabbit If formulation with the human one increased the pacemaking cycle length (CL) from 355 to 1,139 ms. With up to 20% If reduction (a level close to the inhibition of If by ivabradine at clinical concentrations), a modest increase (~5%) in the pacemaking CL was observed with the rabbit If formulation; however, the effect was doubled (~12.4%) for the human If formulation, even though the latter has smaller If density. When the action of acetylcholine (ACh, 0.1 nM) was considered, a 20% If reduction markedly increased the pacemaking CL by 37.5% (~27.3% reduction in the pacing rate), which is similar to the ivabradine effect at clinical concentrations. Theoretical analysis showed that the resultant increase of the pacemaking CL is inversely proportional to the magnitude of Itotal during diastolic depolarization phase: a smaller If in the model resulted in a smaller Itotal amplitude, resulting in a slower pacemaking rate; and the same reduction in If resulted in a more significant change of CL in the cell model with a smaller Itotal. This explained the mechanism by which a low dose of ivabradine slows pacemaking rate more in humans than in the rabbit. Similar results were seen in the Fabbri et al. model of human SAN cells, suggesting our observations are model-independent. Collectively, the results of study explain why low dose ivabradine at clinically relevant concentrations acts as an effective bradycardic agent in modulating human SAN pacemaking.
Collapse
Affiliation(s)
- Xiangyun Bai
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom.,School of Computer Science and Technology, Xi'an University of Posts and Telecommunications, Xi'an, China.,School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Mark R Boyett
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, København, Denmark
| | - Jules C Hancox
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom.,School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, United Kingdom
| | - Henggui Zhang
- Biological Physics Group, Department of Physics and Astronomy, The University of Manchester, Manchester, United Kingdom.,Peng Cheng Laboratory, Shenzhen, China.,Key Laboratory of Medical Electrophysiology of Ministry of Education, Medical Electrophysiological Key Laboratory of Sichuan, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China
| |
Collapse
|
21
|
The HCN channel as a pharmacological target: Why, where, and how to block it. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:173-181. [PMID: 34303730 DOI: 10.1016/j.pbiomolbio.2021.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 06/22/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022]
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, expressed in a variety of cell types and in all tissues, control excitation and rhythm. Since their discovery in neurons and cardiac pacemaker cells, they attracted the attention of medicinal chemistry and pharmacology as novel targets to shape (patho)physiological mechanisms. To date, ivabradine represents the first-in-class drug as specific bradycardic agent in cardiac diseases; however, new applications are emerging in parallel with the demonstration of the involvement of different HCN isoforms in central and peripheral nervous system. Hence, the possibility to target specific isoforms represents an attractive development in this field; indeed, HCN1, HCN2 or HCN4 specific blockers have shown promising features in vitro and in vivo, with remarkable pharmacological differences likely depending on the diverse functional role and tissue distribution. Here, we show a recently developed compound with high potency as HCN2-HCN4 blocker; because of its unique profile, this compound may deserve further investigation.
Collapse
|
22
|
Peters CH, Liu PW, Morotti S, Gantz SC, Grandi E, Bean BP, Proenza C. Bidirectional flow of the funny current (I f) during the pacemaking cycle in murine sinoatrial node myocytes. Proc Natl Acad Sci U S A 2021; 118:e2104668118. [PMID: 34260402 PMCID: PMC8285948 DOI: 10.1073/pnas.2104668118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Sinoatrial node myocytes (SAMs) act as cardiac pacemaker cells by firing spontaneous action potentials (APs) that initiate each heartbeat. The funny current (If) is critical for the generation of these spontaneous APs; however, its precise role during the pacemaking cycle remains unresolved. Here, we used the AP-clamp technique to quantify If during the cardiac cycle in mouse SAMs. We found that If is persistently active throughout the sinoatrial AP, with surprisingly little voltage-dependent gating. As a consequence, it carries both inward and outward current around its reversal potential of -30 mV. Despite operating at only 2 to 5% of its maximal conductance, If carries a substantial fraction of both depolarizing and repolarizing net charge movement during the firing cycle. We also show that β-adrenergic receptor stimulation increases the percentage of net depolarizing charge moved by If, consistent with a contribution of If to the fight-or-flight increase in heart rate. These properties were confirmed by heterologously expressed HCN4 channels and by mathematical models of If Modeling further suggested that the slow rates of activation and deactivation of the HCN4 isoform underlie the persistent activity of If during the sinoatrial AP. These results establish a new conceptual framework for the role of If in pacemaking, in which it operates at a very small fraction of maximal activation but nevertheless drives membrane potential oscillations in SAMs by providing substantial driving force in both inward and outward directions.
Collapse
Affiliation(s)
- Colin H Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Pin W Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, CA 95616
| | - Stephanie C Gantz
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, CA 95616
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| |
Collapse
|
23
|
Mesirca P, Nakao S, Nissen SD, Forte G, Anderson C, Trussell T, Li J, Cox C, Zi M, Logantha S, Yaar S, Cartensen H, Bidaud I, Stuart L, Soattin L, Morris GM, da Costa Martins PA, Cartwright EJ, Oceandy D, Mangoni ME, Jespersen T, Buhl R, Dobrzynski H, Boyett MR, D'Souza A. Intrinsic Electrical Remodeling Underlies Atrioventricular Block in Athletes. Circ Res 2021; 129:e1-e20. [PMID: 33849278 DOI: 10.1161/circresaha.119.316386] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Pietro Mesirca
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Shu Nakao
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Department of Biomedical Sciences, Ritsumeikan University, Japan (S.N.)
| | - Sarah Dalgas Nissen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Gabriella Forte
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Cali Anderson
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Tariq Trussell
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Jue Li
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Charlotte Cox
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Min Zi
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Sunil Logantha
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Liverpool Centre for Cardiovascular Sciences, University of Liverpool, United Kingdom (S.L.)
| | - Sana Yaar
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Helena Cartensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Isabelle Bidaud
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Luke Stuart
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | | | - Gwilym M Morris
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | | | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Delvac Oceandy
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| | - Matteo E Mangoni
- IGF, Université de Montpellier, CNRS, INSERM, France (P.M., I.B., M.E.M.)
| | - Thomas Jespersen
- Department of Biomedical Sciences (T.J., M.R.B.), University of Copenhagen, Denmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences (S.D.N., H.C., R.B.), University of Copenhagen, Denmark
| | - Halina Dobrzynski
- Department of Anatomy, Jagiellonian University Medical College, Poland (H.D.)
| | - Mark R Boyett
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
- Department of Biomedical Sciences (T.J., M.R.B.), University of Copenhagen, Denmark
| | - Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, United Kingdom (S.N., G.F., C.A., T.T., J.L., C.C., M.Z., S.L., S.Y., L. Stuart, L. Soattin, G.M.M., E.J.C., D.O., H.D., M.R.B., A.D.)
| |
Collapse
|
24
|
Dwivedi D, Bhalla US. Physiology and Therapeutic Potential of SK, H, and M Medium AfterHyperPolarization Ion Channels. Front Mol Neurosci 2021; 14:658435. [PMID: 34149352 PMCID: PMC8209339 DOI: 10.3389/fnmol.2021.658435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/13/2021] [Indexed: 12/19/2022] Open
Abstract
SK, HCN, and M channels are medium afterhyperpolarization (mAHP)-mediating ion channels. The three channels co-express in various brain regions, and their collective action strongly influences cellular excitability. However, significant diversity exists in the expression of channel isoforms in distinct brain regions and various subcellular compartments, which contributes to an equally diverse set of specific neuronal functions. The current review emphasizes the collective behavior of the three classes of mAHP channels and discusses how these channels function together although they play specialized roles. We discuss the biophysical properties of these channels, signaling pathways that influence the activity of the three mAHP channels, various chemical modulators that alter channel activity and their therapeutic potential in treating various neurological anomalies. Additionally, we discuss the role of mAHP channels in the pathophysiology of various neurological diseases and how their modulation can alleviate some of the symptoms.
Collapse
Affiliation(s)
- Deepanjali Dwivedi
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States.,Stanley Center at the Broad, Cambridge, MA, United States
| | - Upinder S Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India
| |
Collapse
|
25
|
Nakashima K, Nakao K, Matsui H. Discovery of Novel HCN4 Blockers with Unique Blocking Kinetics and Binding Properties. SLAS DISCOVERY 2021; 26:896-908. [PMID: 34041946 PMCID: PMC8293762 DOI: 10.1177/24725552211013824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) channel underlies the pacemaker currents, called “If,” in sinoatrial nodes (SANs), which regulate heart rhythm. Some HCN4 blockers such as ivabradine have been extensively studied for treating various heart diseases. Studies have shown that these blockers have diverse state dependencies and binding sites, suggesting the existence of potential chemical and functional diversity among HCN4 blockers. Here we report approaches for the identification of novel HCN4 blockers through a random screening campaign among 16,000 small-molecule compounds using an automated patch-clamp system. These molecules exhibited various blockade profiles, and their blocking kinetics and associating amino acids were determined by electrophysiological studies and site-directed mutagenesis analysis, respectively. The profiles of these blockers were distinct from those of the previously reported HCN channel blockers ivabradine and ZD7288. Notably, the mutagenesis analysis showed that blockers with potencies that were increased when the channel was open involved a C478 residue, located at the pore cavity region near the cellular surface of the plasma membrane, while those with potencies that were decreased when the channel was open involved residues Y506 and I510, located at the intracellular region of the pore gate. Thus, this study reported for the first time the discovery of novel HCN4 blockers by screening, and their profiling analysis using an automated patch-clamp system provided chemical tools that will be useful to obtain unique molecular insights into the drug-binding modes of HCN4 and may contribute to the expansion of therapeutic options in the future.
Collapse
Affiliation(s)
- Kosuke Nakashima
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kenji Nakao
- Biomolecular Research Laboratories, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan.,Seedsupply Inc., Fujisawa, Kanagawa, Japan
| | - Hideki Matsui
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| |
Collapse
|
26
|
Abstract
Ivabradine is a unique agent that is distinct from beta-blockers and calcium channel blockers as it reduces heart rate without affecting myocardial contractility or vascular tone. Ivabradine is a use-dependent inhibitor targeting the sinoatrial node. It is approved for use in the United States as an adjunct therapy for heart rate reduction in patients with heart failure with reduced ejection fraction. In this scenario, ivabradine has demonstrated improved clinical outcomes due to reduction in heart failure readmissions. However, there has been conflicting evidence from prospective studies and randomized controlled trials for its use in stable ischemic heart disease regarding efficacy in symptom reduction and mortality benefit. Ivabradine may also play a role in the treatment of patients with inappropriate sinus tachycardia, who often cannot tolerate beta-blockers and/or calcium channel blockers. In this review, we highlight the evidence for the nuances of using ivabradine in heart failure, stable ischemic heart disease, and inappropriate sinus tachycardia to raise awareness for its vital role in the treatment of select populations.
Collapse
|
27
|
Sohrabi C, Saberwal B, Lim WY, Tousoulis D, Ahsan S, Papageorgiou N. Heart Failure in Diabetes Mellitus: An Updated Review. Curr Pharm Des 2020; 26:5933-5952. [PMID: 33213313 DOI: 10.2174/1381612826666201118091659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus (DM) and heart failure (HF) are comorbid conditions associated with significant morbidity and mortality worldwide. Despite the availability of novel and effective therapeutic options and intensive glycaemic control strategies, mortality and hospitalisation rates continue to remain high and the incidence of HF persists. In this review, we described the impact of currently available glucose-lowering therapies in DM with a focus on HF clinical outcomes. Non-conventional modes of management and alternative pathophysiological mechanisms with the potential for therapeutic targeting are also discussed.
Collapse
Affiliation(s)
- Catrin Sohrabi
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Bunny Saberwal
- Electrophysiology Department, Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom
| | - Wei-Yao Lim
- Electrophysiology Department, Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom
| | - Dimitris Tousoulis
- First Cardiology Department, Hippokration Hospital, Athens University Medical School, Athens, Greece
| | - Syed Ahsan
- Electrophysiology Department, Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom
| | - Nikolaos Papageorgiou
- Electrophysiology Department, Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London, United Kingdom
| |
Collapse
|
28
|
Hemodynamic effects of ivabradine use in combination with intravenous inotropic therapy in advanced heart failure. Heart Fail Rev 2020; 26:355-361. [PMID: 32997214 DOI: 10.1007/s10741-020-10029-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/15/2020] [Indexed: 12/28/2022]
Abstract
Intravenous inotropic therapy can be used in patients with advanced heart failure, as palliative therapy or as a bridge to cardiac transplantation or mechanical circulatory support, as well as in cardiogenic shock. Their use is limited to increasing cardiac output in low cardiac output states and reducing ventricular filling pressures to alleviate patient symptoms and improve functional class. Many advanced heart failure patients have sinus tachycardia as a compensatory mechanism to maintain cardiac output. However, excessive sinus tachycardia caused by intravenous inotropes can increase myocardial oxygen consumption, decrease coronary perfusion, and at extreme heart rates decrease ventricular filling and stroke volume. The limited available hemodynamic studies support the hypothesis that adding ivabradine, a rate control agent without negative inotropic effect, may blunt inotrope-induced tachycardia and its associated deleterious effects, while optimizing cardiac output by increasing stroke volume. This review analyzes the intriguing pathophysiology of combined intravenous inotropes and ivabradine to optimize the hemodynamic profile of patients in advanced heart failure. Graphical abstract Illustration of the beneficial and deleterious hemodynamic effects of intravenous inotropes in advanced heart failure, and the positive effects of adding ivabradine.
Collapse
|
29
|
Stanko P, Baka T, Repova K, Aziriova S, Krajcirovicova K, Barta A, Janega P, Adamcova M, Paulis L, Simko F. Ivabradine Ameliorates Kidney Fibrosis in L-NAME-Induced Hypertension. Front Med (Lausanne) 2020; 7:325. [PMID: 32754607 PMCID: PMC7365878 DOI: 10.3389/fmed.2020.00325] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/03/2020] [Indexed: 12/12/2022] Open
Abstract
Hypertension-induced renal injury is characterized by structural kidney alterations and function deterioration. Therapeutics for kidney protection are limited, thus novel renoprotectives in hypertension are being continuously sought out. Ivabradine, an inhibitor of the If current in the sinoatrial node reducing heart rate (HR), was shown to be of benefit in various cardiovascular pathologies. Yet, data regarding potential renoprotection by ivabradine in hypertension are sparse. Thirty-six adult male Wistar rats were divided into non-diseased controls and rats with NG-nitro-L-arginine methyl ester (L-NAME)-induced hypertension to assess ivabradine's site-specific effect on kidney fibrosis. After 4 weeks of treatment, L-NAME increased the average systolic blood pressure (SBP) (by 27%), decreased glomerular density (by 28%) and increased glomerular tuft area (by 44%). Moreover, L-NAME induced glomerular, tubulointerstitial, and vascular/perivascular fibrosis by enhancing type I collagen volume (16-, 19- and 25-fold, respectively). L-NAME also increased the glomerular type IV collagen volume and the tubular injury score (3- and 8-fold, respectively). Ivabradine decreased average SBP and HR (by 8 and 12%, respectively), increased glomerular density (by 57%) and reduced glomerular tuft area (by 30%). Importantly, ivabradine decreased type I collagen volume at all three of the investigated sites (by 33, 38, and 72%, respectively) and enhanced vascular/perivascular type III collagen volume (by 67%). Furthermore, ivabradine decreased the glomerular type IV collagen volume and the tubular injury score (by 63 and 34%, respectively). We conclude that ivabradine attenuated the alterations of glomerular density and tuft area and modified renal fibrosis in a site-specific manner in L-NAME-hypertension. It is suggested that ivabradine may be renoprotective in hypertensive kidney disease.
Collapse
Affiliation(s)
- Peter Stanko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Tomas Baka
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Kristina Repova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Silvia Aziriova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Kristina Krajcirovicova
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Andrej Barta
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Pavol Janega
- Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia.,Institute of Pathological Anatomy, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Michaela Adamcova
- Department of Physiology, School of Medicine, Charles University, Prague, Czechia
| | - Ludovit Paulis
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.,Institute of Normal and Pathological Physiology, Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Fedor Simko
- Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.,3rd Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia.,Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| |
Collapse
|
30
|
Abstract
Ivabradine is a pure heart-rate lowering drug that is nowadays used, accordingly to the last ESC Guidelines, to reduce mortality and heart failure (HF) hospitalization in patients with HF with reduced ejection fraction and in symptomatic patiens with inappropriate sinus tachycardia. Moreover, interesting effect of ivabradine on endothelial and myocardial function and on oxidative stress and inflamation pathways are progressively emerging. The aim of this paper is to highlight newer evidences about ivabradine effect (and consequently possible future application of the drug) in pathological settings different from guidelines-based clinical practice.
Collapse
Affiliation(s)
- Lucia Dallapellegrina
- Cardio-Thoracic Department, ASST Spedali Civili, Piazzale Spedali Civili 1, Brescia, 25128, Italy.,Department of Medical and Surgical Specialties, Cardiology Unit, Radiological Sciences and Public Health, University of Brescia, Italy
| | - Edoardo Sciatti
- Department of Medical and Surgical Specialties, Cardiology Unit, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy.,Cardio-Thoracic Department, ASST Spedali Civili, Brescia, Italy
| | - Enrico Vizzardi
- Department of Medical and Surgical Specialties, Cardiology Unit, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy.,Cardio-Thoracic Department, ASST Spedali Civili, Brescia, Italy
| |
Collapse
|
31
|
Abstract
BACKGROUND Ivabradine is a unique medication that reduces the intrinsic heart rate by specifically blocking the inward funny current that controls the pacemaker activity of the sinus node. We conducted a retrospective cohort study to assess the efficacy of ivabradine in children suffering from postural orthostatic tachycardia syndrome. METHODS A chart review was conducted of patients less than 18 years of age who were diagnosed with postural orthostatic tachycardia syndrome who had received ivabradine as treatment from January 2015 to February 2019 at our institution. Twenty-seven patients (25 females, 92.5%) were identified for the study. The outcomes which were assessed included a change in the severity and frequency of symptoms, heart rate, and blood pressure before and after starting ivabradine. RESULTS There was an improvement in the symptoms of 18 (67%) out of 27 patients. The most notable symptom affected was syncope/presyncope with a reduction in 90%, followed by lightheadedness (85%) and fatigue (81%). The vital signs of the patients showed an overall significant lowering of the heart rate during sitting (89.7 ± 17.9 versus 73.2 ± 12.1; p-value <0.05) and standing (100.5 ± 18.1 versus 80.9 ± 10.1; p-value <0.05) without a significant change in the blood pressure. Two patients had visual disturbances (luminous phenomena). Severe bradycardia and excessive flushing were seen in two patients, respectively. Another one patient reported joint pain and fatigue. CONCLUSION This study indicates that 67% of children treated with ivabradine report an improvement in symptoms.
Collapse
|
32
|
Chen H, Chen Y, Yang J, Wu P, Wang X, Huang C. Effect of Ginkgo biloba extract on pacemaker channels encoded by HCN gene. Herz 2020; 46:255-261. [PMID: 32435840 DOI: 10.1007/s00059-020-04933-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/19/2020] [Accepted: 04/25/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND In the present study, the electropharmacological activity of traditional Chinese medicine, Ginkgo biloba extract (GBE), on human hyperpolarization-activated nucleotide-gated (HCN) channels and the underlying "funny" currents was investigated. METHODS Standard two-electrode voltage-clamp recordings were employed to examine the properties of cloned HCN subunit currents expressed in Xenopus oocytes under controlled conditions and GBE administration. RESULTS We found that GBE irreversibly inhibited the HCN2 and HCN4 channel currents in a concentration-dependent fashion and that the HCN4 current was more sensitive to GBE compared with HCN2. In addition, GBE inhibition of the current amplitudes of HCN2 and HCN4 currents was accompanied by a decrease in the activation and deactivation kinetics. CONCLUSION The results of this study contribute toward illustrating the antiarrhythmic mechanism of GBE, which might be useful for the treatment of arrhythmia.
Collapse
Affiliation(s)
- Hui Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China
| | - Yongjun Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China
| | - Jing Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China
| | - Pan Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China
| | - Xin Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China
| | - Congxin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuchang District, 430060, Wuhan, Hubei Province, China.
- Cardiovascular Research Institute, Wuhan University, 430060, Wuhan, China.
- Hubei Key Laboratory of Cardiology, 430060, Wuhan, China.
| |
Collapse
|
33
|
Wu W, Zhang L, Zhao J, Guo Y, Liu J, Shi D, Yang J, Liu Y, Lai J, Shen Z. Early short-term ivabradine treatment in new-onset acute systolic heart failure and sinus tachycardia patients with inflammatory rheumatic disease. Exp Ther Med 2019; 18:305-311. [PMID: 31258666 PMCID: PMC6566021 DOI: 10.3892/etm.2019.7531] [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: 09/01/2018] [Accepted: 04/05/2019] [Indexed: 11/06/2022] Open
Abstract
Acute heart failure (AHF) is a common complication of inflammatory rheumatic disease (IRD) and usually coexists with tachycardia. Ivabradine, a direct sinus node inhibitor, which was proven to have favorable effects in patients with chronic HF (CHF), has not been sufficiently evaluated in AHF patients regarding its efficacy and safety. The present study sought to explore the effectiveness of early short-term ivabradine treatment in new-onset AHF and concurrent sinus tachycardia in patients with IRD. A total of 12 consecutive patients with IRD, who had new-onset AHF and concurrent sinus tachycardia, were prescribed ivabradine and were retrospectively recruited. Standard medication therapy for AHF was also administered. The heart rate (HR), left ventricular ejection fraction (LVEF), biomarkers of HF and New York Heart Association (NYHA) classification score were compared prior to and after ivabradine treatment. After 48 h of treatment with ivabradine, the mean resting HR decreased from 118.0±13.8 to 83.3±7.3 bpm (P<0.001). Transthoracic echocardiography indicated a significant improvement in the LVEF on an average of 2 weeks after ivabradine prescription when compared with the baseline evaluation (51.2±8.4 vs. 38.0±9.0%; P<0.001). In addition, ivabradine treatment resulted in significantly decreased N-terminal proB-type natriuretic peptide (4,900±3,672 vs. 16,806±16,130 pg/ml; P=0.045) and improvement of the NYHA classification score (2.3±0.6 vs. 3.5±0.5; P<0.001) at 2 weeks when compared with the baseline. Overall, the results of the present study suggested that early use of ivabradine is safe in IRD patients with new-onset AHF and enhances the sinus rate reduction, which may improve heart function.
Collapse
Affiliation(s)
- Wei Wu
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Lixi Zhang
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Jiuliang Zhao
- Department of Rheumatology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Yuchao Guo
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Jinjing Liu
- Department of Rheumatology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Di Shi
- Department of Emergency, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, P.R. China
| | - Jing Yang
- Department of Emergency, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, P.R. China
| | - Yingxian Liu
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Jinzhi Lai
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Zhujun Shen
- Department of Cardiology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, P.R. China
| |
Collapse
|
34
|
Sattar Y, Neisani Samani E, Zafrullah F, Latchana S, Patel NB. Ivabradine in Congestive Heart Failure: Patient Selection and Perspectives. Cureus 2019; 11:e4448. [PMID: 31205834 PMCID: PMC6561528 DOI: 10.7759/cureus.4448] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Heart failure (HF) is the fourth-most frequent cause of death and remains a challenge for public health. Therapy goals for HF with reduced ejection fraction (HFrEF) are the improvement in the quality of life, prolonged survival, a reduction of signs and symptoms, and the prevention of hospitalization. Angiotensin-converting enzyme inhibitors, beta‐blockers, and mineralocorticoid receptor antagonists are the treatments of choice for HFrEF. Although ivabradine is not available in all countries, it is likely a new promising approach to improve outcomes in patients with HFrEF, either alone or with beta-blockers. Here, we review the current knowledge about ivabradine in HFrEF and assess its effect on outcomes in HF.
Collapse
Affiliation(s)
- Yasar Sattar
- Internal Medicine, Icahn School of Medicine at Mount Sinai, New York, USA
| | | | - Fnu Zafrullah
- Internal Medicine, Steward Carney Hospital, Tufts University School of Medicine, Boston, USA
| | - Sharaad Latchana
- Internal Medicine, American University of Integrative Sciences, Tucker, BRB
| | | |
Collapse
|
35
|
Hsiao HT, Liu YC, Liu PY, Wu SN. Concerted suppression of I h and activation of I K(M) by ivabradine, an HCN-channel inhibitor, in pituitary cells and hippocampal neurons. Brain Res Bull 2019; 149:11-20. [PMID: 30951796 DOI: 10.1016/j.brainresbull.2019.03.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 11/24/2022]
Abstract
Ivabradine (IVA), a heart-rate reducing agent, is recognized as an inhibitor of hyperpolarization-activated cation current (Ih) and also reported to ameliorate inflammatory or neuropathic pain. However, to what extent this agent can perturb another types of membrane ion currents in neurons or endocrine cells remains to be largely unknown. Therefore, the Ih or other types of ionic currents in pituitary tumor (GH3) cells and in hippocampal mHippoE-14 neurons was studied with or without the presence of IVA or other related compounds. The IVA addition caused a time- and concentration-dependent reduction in the amplitude of Ih with an IC50 value of 0.64 μM and a KD value of 0.68 μM. IVA (0.3 μM) shifted the Ih activation curve to a more negative potential by approximately 8 mV, despite no concomitant change in the gating charge. Additionally, IVA was found to increase M-type K+ current (IK(M)) together with a rightward shift in the activation curve. In cell-attached current recordings, IVA (3 μM) applied to the bath increased the open probability of M-type K+ channels; however, it did not modify single-channel conductance of the channel. In current-clamp voltage recordings, IVA suppressed the firing of spontaneous action potentials in GH3 cells; and, further addition of linopirdine attenuated its suppression of firing. In hippocampal mHippoE-14 neurons, IVA also effectively increased IK(M) amplitude. In summary, both inhibition of Ih and activation of IK(M) caused by IVA can synergistically combine to influence electrical behaviors in different types of electrically excitable cells occurring in vivo.
Collapse
Affiliation(s)
- Hung-Tsung Hsiao
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Taiwan
| | - Yen-Chin Liu
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Taiwan
| | - Ping-Yen Liu
- Division of Cardiovascular Medicine, National Cheng Kung University Medical College, Tainan City, Taiwan
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, Taiwan; Department of Physiology, National Cheng Kung University Medical College, Tainan City, Taiwan.
| |
Collapse
|
36
|
Fragasso G, Margonato A, Spoladore R, Lopaschuk GD. Metabolic effects of cardiovascular drugs. Trends Cardiovasc Med 2019; 29:176-187. [DOI: 10.1016/j.tcm.2018.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/12/2018] [Accepted: 08/03/2018] [Indexed: 01/04/2023]
|
37
|
Tanguay J, Callahan KM, D'Avanzo N. Characterization of drug binding within the HCN1 channel pore. Sci Rep 2019; 9:465. [PMID: 30679654 PMCID: PMC6345760 DOI: 10.1038/s41598-018-37116-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/29/2018] [Indexed: 11/09/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediate rhythmic electrical activity of cardiac pacemaker cells, and in neurons play important roles in setting resting membrane potentials, dendritic integration, neuronal pacemaking, and establishing action potential threshold. Block of HCN channels slows the heart rate and is currently used to treat angina. However, HCN block also provides a promising approach to the treatment of neuronal disorders including epilepsy and neuropathic pain. While several molecules that block HCN channels have been identified, including clonidine and its derivative alinidine, lidocaine, mepivacaine, bupivacaine, ZD7288, ivabradine, zatebradine, and cilobradine, their low affinity and lack of specificity prevents wide-spread use. Different studies suggest that the binding sites of these inhibitors are located in the inner vestibule of HCN channels, but the molecular details of their binding remain unknown. We used computational docking experiments to assess the binding sites and mode of binding of these inhibitors against the recently solved atomic structure of human HCN1 channels, and a homology model of the open pore derived from a closely related CNG channel. We identify a possible hydrophobic groove in the pore cavity that plays an important role in conformationally restricting the location and orientation of drugs bound to the inner vestibule. Our results also help explain the molecular basis of the low-affinity binding of these inhibitors, paving the way for the development of higher affinity molecules.
Collapse
Affiliation(s)
- Jérémie Tanguay
- Department of Physics, Université de Montréal, Montréal, Canada
| | - Karen M Callahan
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada.
| |
Collapse
|
38
|
Dini L, Del Lungo M, Resta F, Melchiorre M, Spinelli V, Di Cesare Mannelli L, Ghelardini C, Laurino A, Sartiani L, Coppini R, Mannaioni G, Cerbai E, Romanelli MN. Selective Blockade of HCN1/HCN2 Channels as a Potential Pharmacological Strategy Against Pain. Front Pharmacol 2018; 9:1252. [PMID: 30467478 PMCID: PMC6237106 DOI: 10.3389/fphar.2018.01252] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 10/15/2018] [Indexed: 12/25/2022] Open
Abstract
A prominent role of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels has been suggested based on their expression and (dys)function in dorsal root ganglion (DRG) neurons, being likely involved in peripheral nociception. Using HCN blockers as antinociceptive drugs is prevented by the widespread distribution of these channels. However, tissue-specific expression of HCN isoforms varies significantly, HCN1 and HCN2 being considered as major players in DRG excitability. We characterized the pharmacological effect of a novel compound, MEL55A, able to block selectively HCN1/HCN2 isoforms, on DRG neuron excitability in-vitro and for its antiallodynic properties in-vivo. HEK293 cells expressing HCN1, HCN2, or HCN4 isoforms were used to verify drug selectivity. The pharmacological profile of MEL55A was tested on mouse DRG neurons by patch-clamp recordings, and in-vivo in oxaliplatin-induced neuropathy by means of thermal hypersensitivity. Results were compared to the non-isoform-selective drug, ivabradine. MEL55A showed a marked preference toward HCN1 and HCN2 isoforms expressed in HEK293, with respect to HCN4. In cultured DRG, MEL55A reduced I h amplitude, both in basic conditions and after stimulation by forskolin, and cell excitability, its effect being quantitatively similar to that observed with ivabradine. MEL55A was able to relieve chemotherapy-induced neuropathic pain. In conclusion, selective blockade of HCN1/HCN2 channels, over HCN4 isoform, was able to modulate electrophysiological properties of DRG neurons similarly to that reported for classical I h blockers, ivabradine, resulting in a pain-relieving activity. The availability of small molecules with selectivity toward HCN channel isoforms involved in nociception might represent a safe and effective strategy against chronic pain.
Collapse
Affiliation(s)
- Leonardo Dini
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Martina Del Lungo
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Francesco Resta
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Michele Melchiorre
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Valentina Spinelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Lorenzo Di Cesare Mannelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Carla Ghelardini
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Annunziatina Laurino
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Laura Sartiani
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Raffaele Coppini
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Guido Mannaioni
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| | - Maria Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NeuroFarBa), University of Florence, Florence, Italy
| |
Collapse
|
39
|
Cao Y, Chen S, Liang Y, Wu T, Pang J, Liu S, Zhou P. Inhibition of hyperpolarization-activated cyclic nucleotide-gated channels by β-blocker carvedilol. Br J Pharmacol 2018; 175:3963-3975. [PMID: 30098004 DOI: 10.1111/bph.14469] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 07/02/2018] [Accepted: 07/30/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Carvedilol is a clinically effective β-blocker broadly used for treating congestive heart failure (CHF), and several clinical trials have demonstrated that it shows a favourable effect compared with other β-blockers in patients with CHF. The mechanism underlying this beneficial effect of carvedilol compared to other β-blockers is not clearly understood. In addition to β-blockers, inhibitors of hyperpolarization-activated cyclic nucleotide (HCN)-gated channels, which play a critical role in spontaneous rhythmic activity in the heart, have also been proposed to be suitable drugs for reducing heart rate and, therefore, beneficial for treating CHF. In the present study, we investigated the effect of carvedilol on HCN channels. EXPERIMENTAL APPROACH Whole-cell patch-clamp recordings were used to assess the effect of carvedilol on currents from wild-type and mutant HCN1, HCN2 and HCN4 channels expressed in CHO cells. KEY RESULTS Carvedilol was the only β-blocker tested that showed inhibitory effects on the major sinoatrial HCN channel isoform HCN4. Carvedilol inhibited HCN4 in a concentration-dependent manner with an EC50 of 4.4 μM. In addition, carvedilol also inhibited HCN1 and HCN2 channels. Carvedilol blocked HCN channels by decelerating the rate of channel activation and increasing that of deactivation, and shifted the voltage-dependence of activation leftwards. Our data also showed that carvedilol, unlike other inhibitors of this channel (ivabradine and ZD7288), is not an 'open-channel' inhibitor of HCN4. CONCLUSIONS AND IMPLICATIONS Carvedilol is a negative gating modulator of HCN channels. It represents a novel structure for future drug design of HCN channel inhibitors.
Collapse
Affiliation(s)
- Ying Cao
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Shujun Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Yemei Liang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Ting Wu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Jianxin Pang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Shuwen Liu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.,State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Southern Medical University, Guangzhou, China
| | - Pingzheng Zhou
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| |
Collapse
|
40
|
Xie A, Zhou A, Liu H, Shi G, Liu M, Boheler KR, Dudley SC. Mitochondrial Ca2+ flux modulates spontaneous electrical activity in ventricular cardiomyocytes. PLoS One 2018; 13:e0200448. [PMID: 30001390 PMCID: PMC6042741 DOI: 10.1371/journal.pone.0200448] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/26/2018] [Indexed: 11/23/2022] Open
Abstract
Introduction Ca2+ release from sarcoplasmic reticulum (SR) is known to contribute to automaticity via the cytoplasmic Na+-Ca2+ exchanger (NCX). Mitochondria participate in Ca2+ cycling. We studied the role of mitochondrial Ca2+ flux in ventricular spontaneous electrical activity. Methods Spontaneously contracting mouse embryonic stem cells (ESC)-derived ventricular cardiomyocytes (CMs) were differentiated from wild type and ryanodine receptor type 2 (RYR2) knockout mouse ESCs and differentiated for 19–21 days. Automaticity was also observed in human induced pluripotent stem cell (hiPSC)-derived ventricular CMs differentiated for 30 days, and acute isolated adult mouse ventricular cells in ischemic simulated buffer. Action potentials (APs) were recorded by perforated whole cell current-clamp. Cytoplasmic and mitochondrial Ca2+ transients were determined by fluorescent imaging. Results In mouse ESC-derived ventricular CMs, spontaneous beating was dependent on the L-type Ca2+ channel, cytoplasmic NCX and mitochondrial NCX. Spontaneous beating was modulated by SR Ca2+ release from RYR2 or inositol trisphosphate receptors (IP3R), the pacemaker current (If) and mitochondrial Ca2+ uptake by the mitochondrial Ca2+ uniporter (MCU). In RYR2 knockout mouse ESC-derived ventricular CMs, mitochondrial Ca2+ flux influenced spontaneous beating independently of the SR Ca2+ release from RYR2, and the mitochondrial effect was dependent on IP3R SR Ca2+ release. Depolarization of mitochondria and preservation of ATP could terminate spontaneous beating. A contribution of mitochondrial Ca2+ flux to automaticity was confirmed in hiPSC-derived ventricular CMs and ischemic adult mouse ventricular CMs, confirming the findings across species and cell maturity levels. Conclusions Mitochondrial and sarcolemma NCX fluxes are required for ventricular automaticity. Mitochondrial Ca2+ uptake plays a modulatory role. Mitochondrial Ca2+ uptake through MCU is influenced by IP3R-dependent SR Ca2+ release.
Collapse
Affiliation(s)
- An Xie
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Anyu Zhou
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Hong Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Guangbin Shi
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Man Liu
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
| | - Kenneth R. Boheler
- Stem Cell and Regenerative Medicine Consortium, LKS Faculty of Medicine, Hong Kong University, Hong Kong, P.R. China
| | - Samuel C. Dudley
- Department of Medicine, Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, United States of America
- * E-mail:
| |
Collapse
|
41
|
Badu-Boateng C, Jennings R, Hammersley D. The therapeutic role of ivabradine in heart failure. Ther Adv Chronic Dis 2018; 9:199-207. [PMID: 30364460 DOI: 10.1177/2040622318784556] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 05/30/2018] [Indexed: 12/18/2022] Open
Abstract
Heart failure represents a major global cause of morbidity and mortality. Ivabradine is a selective funny current (If) inhibitor, which acts on the sinoatrial node, resulting in a reduction in heart rate. Ivabradine is currently licensed for use in patients with symptomatic heart failure with reduced ejection fraction and a heart rate persistently at least 70 beats per minute in spite of otherwise optimal prognostic heart failure pharmacotherapy. In this review article, we examine the mechanism of action of ivabradine, evaluate the clinical trials underpinning its application in heart failure and discuss its current recommended clinical use in this capacity.
Collapse
Affiliation(s)
| | - Robert Jennings
- Department of Medicine, Frimley Park Hospital, Frimley, Camberley, UK
| | - Daniel Hammersley
- Department of Cardiology, Kings College Hospital NHS Foundation Trust, Denmark Hill, London SE5 9RS, UK
| |
Collapse
|
42
|
Meyer M, Rambod M, LeWinter M. Pharmacological heart rate lowering in patients with a preserved ejection fraction-review of a failing concept. Heart Fail Rev 2018; 23:499-506. [PMID: 29098508 PMCID: PMC5934348 DOI: 10.1007/s10741-017-9660-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Epidemiological studies have demonstrated that high resting heart rates are associated with increased mortality. Clinical studies in patients with heart failure and reduced ejection fraction have shown that heart rate lowering with beta-blockers and ivabradine improves survival. It is therefore often assumed that heart rate lowering is beneficial in other patients as well. Here, we critically appraise the effects of pharmacological heart rate lowering in patients with both normal and reduced ejection fraction with an emphasis on the effects of pharmacological heart rate lowering in hypertension and heart failure. Emerging evidence from recent clinical trials and meta-analyses suggest that pharmacological heart rate lowering is not beneficial in patients with a normal or preserved ejection fraction. This has just begun to be reflected in some but not all guideline recommendations. The detrimental effects of pharmacological heart rate lowering are due to an increase in central blood pressures, higher left ventricular systolic and diastolic pressures, and increased ventricular wall stress. Therefore, we propose that heart rate lowering per se reproduces the hemodynamic effects of diastolic dysfunction and imposes an increased arterial load on the left ventricle, which combine to increase the risk of heart failure and atrial fibrillation. Pharmacologic heart rate lowering is clearly beneficial in patients with a dilated cardiomyopathy but not in patients with normal chamber dimensions and normal systolic function. These conflicting effects can be explained based on a model that considers the hemodynamic and ventricular structural effects of heart rate changes.
Collapse
Affiliation(s)
- Markus Meyer
- Department of Medicine, Cardiology Division, Larner College of Medicine at the University of Vermont, UVMMC, McClure 1, Cardiology, 111 Colchester Avenue, Burlington, VT, 05401, USA.
- Department of Medicine, Cardiology Division, Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA.
| | - Mehdi Rambod
- Department of Medicine, Cardiology Division, Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA
| | - Martin LeWinter
- Department of Medicine, Cardiology Division, Larner College of Medicine at the University of Vermont, Burlington, VT, 05405, USA
| |
Collapse
|
43
|
Chow SL, Page RL, Depre C. Role of ivabradine and heart rate lowering in chronic heart failure: guideline update. Expert Rev Cardiovasc Ther 2018; 16:515-526. [PMID: 29902387 DOI: 10.1080/14779072.2018.1489235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION This review summarizes the current management of heart failure (HF) in patients with reduced ejection fraction and the potential role of heart rate lowering agents in select populations, as recommended in the updated guidelines. Areas covered: PubMed was searched for studies that evaluated the role of heart rate lowering or ivabradine in HF management. Expert commentary: Targeting heart rate may offer benefit when added to renin-angiotensin aldosterone antagonists, and beta-blockers. Ivabradine is a heart rate lowering agent that acts on the funny current (If) in the sinoatrial node, thereby reducing heart rate without directly affecting cardiac contraction and relaxation. Clinical data from a phase III trial demonstrated that ivabradine reduced the composite end point of cardiovascular death or hospital admission for worsening systolic HF, while maintaining an acceptable safety profile in patients receiving standard of care therapy. These data, in addition to more recently published guidelines, suggest ivabradine as a promising new treatment option for lowering heart rate after optimizing standard therapy in select patients with chronic HF.
Collapse
Affiliation(s)
- Sheryl L Chow
- a Department of Pharmacy , Western University of Health Sciences , Pomona , CA , USA
| | - Robert L Page
- b Department of Clinical Pharmacy , University of Colorado , Denver , CO , USA
| | - Christophe Depre
- c Clinical Research Medical Director , Amgen Inc ., Thousand Oaks , CA , USA
| |
Collapse
|
44
|
Cardiac pacemaker channel (HCN4) inhibition and atrial arrhythmogenesis after releasing cardiac sympathetic activation. Sci Rep 2018; 8:7748. [PMID: 29773827 PMCID: PMC5958126 DOI: 10.1038/s41598-018-26099-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/24/2018] [Indexed: 01/22/2023] Open
Abstract
Clinical trials and studies with ivabradine implicate cardiac pacemaker channels (HCN4) in the pathogenesis of atrial arrhythmias. Because acute changes in cardiac autonomic tone predispose to atrial arrhythmias, we studied humans in whom profound cardiac sympathetic activation was rapidly relieved to test influences of HCN4 inhibition with ivabradine on atrial arrhythmias. We tested 19 healthy participants with ivabradine, metoprolol, or placebo in a double blind, randomized, cross-over fashion on top of selective norepinephrine reuptake inhibition with reboxetine. Subjects underwent combined head up tilt plus lower body negative pressure testing followed by rapid return to the supine position. In the current secondary analysis with predefined endpoints before data unblinding, continuous finger blood pressure and ECG recordings were analyzed by two experienced cardiac electrophysiologists and a physician, blinded for treatment assignment. The total atrial premature activity (referred to as atrial events) at baseline did not differ between treatments. After backwards tilting, atrial events were significantly higher with ivabradine compared with metoprolol or with placebo. Unlike beta-adrenoreceptor blockade, HCN4 inhibition while lowering heart rate does not protect from atrial arrhythmias under conditions of experimental cardiac sympathetic activation. The model in addition to providing insight in the role of HCN4 in human atrial arrhythmogenesis may have utility in gauging potential atrial pro-arrhythmic drug properties.
Collapse
|
45
|
Kaski JC, Gloekler S, Ferrari R, Fox K, Lévy BI, Komajda M, Vardas P, Camici PG. Role of ivabradine in management of stable angina in patients with different clinical profiles. Open Heart 2018; 5:e000725. [PMID: 29632676 PMCID: PMC5888443 DOI: 10.1136/openhrt-2017-000725] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/29/2017] [Accepted: 02/14/2018] [Indexed: 12/12/2022] Open
Abstract
In chronic stable angina, elevated heart rate contributes to the development of symptoms and signs of myocardial ischaemia by increasing myocardial oxygen demand and reducing diastolic perfusion time. Accordingly, heart rate reduction is a well-known strategy for improving both symptoms of myocardial ischaemia and quality of life (QOL). The heart rate-reducing agent ivabradine, a direct and selective inhibitor of the If current, decreases myocardial oxygen consumption while increasing diastolic time, without affecting myocardial contractility or coronary vasomotor tone. Ivabradine is indicated for treatment of stable angina and chronic heart failure (HF). This review examines available evidence regarding the efficacy and safety of ivabradine in stable angina, when used as monotherapy or in combination with beta-blockers, in particular angina subgroups and in patients with stable angina with left ventricular systolic dysfunction (LVSD) or HF. Trials involving more than 45 000 patients receiving treatment with ivabradine have shown that this agent has antianginal and anti-ischaemic effects, regardless of age, sex, severity of angina, revascularisation status or comorbidities. This heart rate-lowering agent might also improve prognosis, reduce hospitalisation rates and improve QOL in angina patients with chronic HF and LVSD.
Collapse
Affiliation(s)
- Juan Carlos Kaski
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK
| | - Steffen Gloekler
- Department of Cardiology, Schwarzwald-Baar Klinikum, Villingen-Schwenningen, Germany.,Cardiology, Cardiovascular Department, Bern University Hospital, Bern, Switzerland
| | - Roberto Ferrari
- Centro Cardiologico Universitario di Ferrara, University of Ferrara, Ferrara, Italy.,Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy
| | - Kim Fox
- National Heart and Lung Institute, Imperial College, Institute of Cardiovascular Medicine and Science, Royal Brompton Hospital, London, UK
| | - Bernard I Lévy
- PARCC, INSERM U970, Vessels and Blood Institute, Hôpital Lariboisière, Paris, France
| | - Michel Komajda
- Department of Cardiology, Université Pierre et Marie Curie Paris VI, La Pitié-Salpêtrière Hospital, Paris, France
| | - Panos Vardas
- Cardiology Department, University Hospital of Heraklion, Heraklion, Greece
| | - Paolo G Camici
- Cardiology Department, Vita Salute University and San Raffaele Hospital, Milan, Italy
| |
Collapse
|
46
|
Role of the Funny Current Inhibitor Ivabradine in Cardiac Pharmacotherapy: A Systematic Review. Am J Ther 2018; 25:e247-e266. [DOI: 10.1097/mjt.0000000000000388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
47
|
Abstract
OBJECTIVE Ivabradine is a selective and specific inhibitor of the I(f) current in the sinoatrial and atrioventricular nodes. It decreases heart rate and myocardial oxygen consumption at rest and during exercise. It is used in adults for management of heart failure and angina, but promising results have been obtained in postural orthostatic tachycardia syndrome (POTS). There is little experience of ivabradine in childhood, although it is used on a compassionate basis. Our aim was to review our experience of ivabradine in a retrospective evaluation of pediatric patients with POTS. METHODS We evaluated all patients younger than 18 years for whom ivabradine had been prescribed for this indication, from February 2008 to June 2014. RESULTS Twenty-two patients were identified (15 female). Median age was 14.5 years (11-17 years). The ivabradine dosage after up-titration was 0.1 mg/kg per dose twice daily. In 15 (68%) symptoms improved. Ivabradine was suspended in five, but only in one for worsening of symptoms. There was a reduction in heart rate on resting electrocardiogram (EKG) from a mean (standard deviation) of 82.5 (13.6) bpm to a mean of 71 (16.5) bpm (p = 0.007). No patient had increased duration of QTc (p = 0.44). One (4.5%) experienced phosphenes. CONCLUSIONS From this initial experience, ivabradine is safe in patients younger than 18 years with POTS. We observed improvement of symptoms in 68% and phosphenes in less than 5%. Further studies are needed to assess the safety in a randomized control setting.
Collapse
|
48
|
|
49
|
Mengesha HG, Tafesse TB, Bule MH. If Channel as an Emerging Therapeutic Target for Cardiovascular Diseases: A Review of Current Evidence and Controversies. Front Pharmacol 2017; 8:874. [PMID: 29225577 PMCID: PMC5705549 DOI: 10.3389/fphar.2017.00874] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 11/13/2017] [Indexed: 01/09/2023] Open
Abstract
In 2015, non-communicable diseases accounted for 39.5 million (70%) of the total 56.4 million deaths that occurred globally, of which 17.7 million (45%) were due to cardiovascular diseases. An elevated heart rate is considered to be one of the independent predictors and markers of future cardiovascular diseases. A variety of experimental and epidemiological studies have found that atherosclerosis, heart failure, coronary artery disease, stroke, and arrhythmia are linked to elevated heart rate. Although there are established drugs to reduce the heart rate, these drugs have undesirable side effects. Hence, the development of new drugs that selectively inhibit the heart rate is considered necessary. In the search for such drugs, almost four decades ago the If channel, also known as the “funny channel,” emerged as a novel site for the selective inhibition of heart rate. These If channels, with a mixed sodium and potassium inward current, have been identified in the sinoatrial node of the heart, which mediates the slow diastolic depolarization of the pacemaker of the spontaneous rhythmic cells. The hyperpolarization-activated cyclic nucleotide-gated (HCN) subfamily is primarily articulated in the heart and neurons that are encoded by a family of four genes (HCN1-4) and they identify the funny channel. Of these, HCN-4 is the principal protein in the sinoatrial node. Currently, funny channel inhibition is being targeted for the treatment and prevention of cardiovascular diseases such as atherosclerosis and stroke. A selective If channel inhibitor named ivabradine was discovered for clinical use in treating heart failure and coronary artery disease. However, inconsistencies regarding the clinical effects of ivabradine have been reported in the literature, suggesting the need for a rigorous analysis of the available evidence. The objective of this review is therefore to assess the current advances in targeting the If channel associated with ivabradine and related challenges.
Collapse
Affiliation(s)
- Hayelom G Mengesha
- Pharmacology and Toxicology Research Unit, School of Pharmacy, Mekelle University, Mekelle, Ethiopia.,College of Medicine and Health Science, Adigrat University, Adigrat, Ethiopia
| | - Tadesse B Tafesse
- School of Pharmacy, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Mohammed H Bule
- Department of Pharmacy, College of Medicine and Health Sciences, Ambo University, Ambo, Ethiopia
| |
Collapse
|
50
|
Bagliani G, Leonelli F, Padeletti L. P Wave and the Substrates of Arrhythmias Originating in the Atria. Card Electrophysiol Clin 2017; 9:365-382. [PMID: 28838546 DOI: 10.1016/j.ccep.2017.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The sinus node is the primary cardiac pacemaker from which the wavefront of activation proceeds through bundles of atrial fibers to the atrioventricular node. Left atrial activation proceeds along the Bachmann bundle and lower right atrium, determining P-wave morphology. Electrocardiogram reveals ectopic or retrograde atrial activation, wandering pacemaker activity, or artificial pacemaker-mediated atrial depolarization. Vectorcardiography and transesophageal recording are complementary methods. Atrial anatomic structure and automatic cells outside the sinus node constitute the mechanisms of focal and reentrant atrial arrhythmias. Arrhythmias with specific arrhythmogenic mechanisms correspond to precise electrocardiographic morphology for accurate diagnosis.
Collapse
Affiliation(s)
- Giuseppe Bagliani
- Arrhythmology Unit, Cardiology Department, Foligno General Hospital, Via Massimo Arcamone, 06034 Foligno (PG), Italy; Cardiovascular Diseases Department, University of Perugia, Piazza Menghini 1, 06129 Perugia, Italy.
| | - Fabio Leonelli
- Cardiology Department James A. Haley Veterans' Hospital, University South Florida, 13000 Bruce B Down Boulevard, Tampa, FL 33612, USA
| | - Luigi Padeletti
- Heart and Vessels Department, University of Florence, Largo Brambilla, 3, 50134 Florence, Italy; IRCCS Multimedica, Cardiology Department, Via Milanese, 300, 20099 Sesto San Giovanni, Italy
| |
Collapse
|