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Dorey TW, McRae MD, Belke DD, Rose RA. PDE4D mediates impaired β-adrenergic receptor signalling in the sinoatrial node in mice with hypertensive heart disease. Cardiovasc Res 2023; 119:2697-2711. [PMID: 37643895 PMCID: PMC10757582 DOI: 10.1093/cvr/cvad138] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 06/06/2023] [Accepted: 07/18/2023] [Indexed: 08/31/2023] Open
Abstract
AIMS The sympathetic nervous system increases HR by activating β-adrenergic receptors (β-ARs) and increasing cAMP in sinoatrial node (SAN) myocytes while phosphodiesterases (PDEs) degrade cAMP. Chronotropic incompetence, the inability to regulate heart rate (HR) in response to sympathetic nervous system activation, is common in hypertensive heart disease; however, the basis for this is poorly understood. The objective of this study was to determine the mechanisms leading to chronotropic incompetence in mice with angiotensin II (AngII)-induced hypertensive heart disease. METHODS AND RESULTS C57BL/6 mice were infused with saline or AngII (2.5 mg/kg/day for 3 weeks) to induce hypertensive heart disease. HR and SAN function in response to the β-AR agonist isoproterenol (ISO) were studied in vivo using telemetry and electrocardiography, in isolated atrial preparations using optical mapping, in isolated SAN myocytes using patch-clamping, and using molecular biology. AngII-infused mice had smaller increases in HR in response to physical activity and during acute ISO injection. Optical mapping of the SAN in AngII-infused mice demonstrated impaired increases in conduction velocity and altered conduction patterns in response to ISO. Spontaneous AP firing responses to ISO in isolated SAN myocytes from AngII-infused mice were impaired due to smaller increases in diastolic depolarization (DD) slope, hyperpolarization-activated current (If), and L-type Ca2+ current (ICa,L). These changes were due to increased localization of PDE4D surrounding β1- and β2-ARs in the SAN, increased SAN PDE4 activity, and reduced cAMP generation in response to ISO. Knockdown of PDE4D using a virus-delivered shRNA or inhibition of PDE4 with rolipram normalized SAN sensitivity to β-AR stimulation in AngII-infused mice. CONCLUSIONS AngII-induced hypertensive heart disease results in impaired HR responses to β-AR stimulation due to up-regulation of PDE4D and reduced effects of cAMP on spontaneous AP firing in SAN myocytes.
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Affiliation(s)
- Tristan W Dorey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Megan D McRae
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
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Dorey TW, Liu Y, Jansen HJ, Bohne LJ, Mackasey M, Atkinson L, Prasai S, Belke DD, Fatehi-Hassanabad A, Fedak PWM, Rose RA. Natriuretic Peptide Receptor B Protects Against Atrial Fibrillation by Controlling Atrial cAMP Via Phosphodiesterase 2. Circ Arrhythm Electrophysiol 2023; 16:e012199. [PMID: 37933567 DOI: 10.1161/circep.123.012199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/19/2023] [Indexed: 11/08/2023]
Abstract
BACKGROUND β-AR (β-adrenergic receptor) stimulation regulates atrial electrophysiology and Ca2+ homeostasis via cAMP-dependent mechanisms; however, enhanced β-AR signaling can promote atrial fibrillation (AF). CNP (C-type natriuretic peptide) can also regulate atrial electrophysiology through the activation of NPR-B (natriuretic peptide receptor B) and cGMP-dependent signaling. Nevertheless, the role of NPR-B in regulating atrial electrophysiology, Ca2+ homeostasis, and atrial arrhythmogenesis is incompletely understood. METHODS Studies were performed using atrial samples from human patients with AF or sinus rhythm and in wild-type and NPR-B-deficient (NPR-B+/-) mice. Studies were conducted in anesthetized mice by intracardiac electrophysiology, in isolated mouse atrial preparations using high-resolution optical mapping, in isolated mouse and human atrial myocytes using patch-clamping and Ca2+ imaging, and in mouse and human atrial tissues using molecular biology. RESULTS Atrial NPR-B protein levels were reduced in patients with AF, and NPR-B+/- mice were more susceptible to AF. Atrial cGMP levels and PDE2 (phosphodiesterase 2) activity were reduced in NPR-B+/- mice leading to larger increases in atrial cAMP in the presence of the β-AR agonist isoproterenol. NPR-B+/- mice displayed larger increases in action potential duration and L-type Ca2+ current in the presence of isoproterenol. This resulted in the occurrence of spontaneous sarcoplasmic reticulum Ca2+ release events and delayed afterdepolarizations in NPR-B+/- atrial myocytes. Phosphorylation of the RyR2 (ryanodine receptor) and phospholamban was increased in NPR-B+/- atria in the presence of isoproterenol compared with the wildtypes. C-type natriuretic peptide inhibited isoproterenol-stimulated L-type Ca2+ current through PDE2 in mouse and human atrial myocytes. CONCLUSIONS NPR-B protects against AF by preventing enhanced atrial responses to β-adrenergic receptor agonists.
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Affiliation(s)
- Tristan W Dorey
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Yingjie Liu
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Hailey J Jansen
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Loryn J Bohne
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Martin Mackasey
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Logan Atkinson
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada (L.A.)
| | - Shuvam Prasai
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Darrell D Belke
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Ali Fatehi-Hassanabad
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Paul W M Fedak
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
| | - Robert A Rose
- Department of Cardiac Sciences (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., D.D.B, A.F.-H., P.W.M.F., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
- Department of Physiology and Pharmacology (T.W.D., Y.L., H.J.J., L.J.B., M.M., S.P., R.A.R.), Libin Cardiovascular Institute, Cumming School of Medicine University of Calgary, Alberta, Canada
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Tibbo AJ, Mika D, Dobi S, Ling J, McFall A, Tejeda GS, Blair C, MacLeod R, MacQuaide N, Gök C, Fuller W, Smith BO, Smith GL, Vandecasteele G, Brand T, Baillie GS. Phosphodiesterase type 4 anchoring regulates cAMP signaling to Popeye domain-containing proteins. J Mol Cell Cardiol 2022; 165:86-102. [PMID: 34999055 PMCID: PMC8986152 DOI: 10.1016/j.yjmcc.2022.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/16/2021] [Accepted: 01/03/2022] [Indexed: 12/04/2022]
Abstract
Cyclic AMP is a ubiquitous second messenger used to transduce intracellular signals from a variety of Gs-coupled receptors. Compartmentalisation of protein intermediates within the cAMP signaling pathway underpins receptor-specific responses. The cAMP effector proteins protein-kinase A and EPAC are found in complexes that also contain phosphodiesterases whose presence ensures a coordinated cellular response to receptor activation events. Popeye domain containing (POPDC) proteins are the most recent class of cAMP effectors to be identified and have crucial roles in cardiac pacemaking and conduction. We report the first observation that POPDC proteins exist in complexes with members of the PDE4 family in cardiac myocytes. We show that POPDC1 preferentially binds the PDE4A sub-family via a specificity motif in the PDE4 UCR1 region and that PDE4s bind to the Popeye domain of POPDC1 in a region known to be susceptible to a mutation that causes human disease. Using a cell-permeable disruptor peptide that displaces the POPDC1-PDE4 complex we show that PDE4 activity localized to POPDC1 modulates cycle length of spontaneous Ca2+ transients firing in intact mouse sinoatrial nodes. POPDC1 forms a complex with type 4 phosphodiesterases (PDE4s) in cardiac myocytes. POPDC1 binds PDE4 enzymes in the Upstream Conserved Region 1 (UCR1) domain. The PDE4 binding motif within the Popeye domain lies in a region that harbours a mutation, which underpins human disease. Disruption of the POPDC1-PDE4 complex modulates the cycle length of spontaneous Ca2+ transients in the sinoatrial node. Disruption of the POPDC1-PDE4 complex causes a significant prolongation of the action potential repolarization phase.
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Affiliation(s)
- Amy J Tibbo
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Delphine Mika
- Université Paris-Saclay, Inserm, Signaling and Cardiovascular Pathophysiology, UMR-S 1180, 92296 Châtenay-Malabry, France
| | - Sara Dobi
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Jiayue Ling
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Aisling McFall
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Gonzalo S Tejeda
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Connor Blair
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Ruth MacLeod
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Niall MacQuaide
- School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Caglar Gök
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - William Fuller
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Brian O Smith
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Godfrey L Smith
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK
| | - Grégoire Vandecasteele
- Université Paris-Saclay, Inserm, Signaling and Cardiovascular Pathophysiology, UMR-S 1180, 92296 Châtenay-Malabry, France
| | - Thomas Brand
- National Heart and Lung Institute, Imperial College, W12 0NN, London
| | - George S Baillie
- College of Veterinary, Medical and Life Sciences, University of Glasgow, Glasgow G128QQ, UK.
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Agarwal SR, Sherpa RT, Moshal KS, Harvey RD. Compartmentalized cAMP signaling in cardiac ventricular myocytes. Cell Signal 2022; 89:110172. [PMID: 34687901 PMCID: PMC8602782 DOI: 10.1016/j.cellsig.2021.110172] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/15/2021] [Accepted: 10/17/2021] [Indexed: 01/03/2023]
Abstract
Activation of different receptors that act by generating the common second messenger cyclic adenosine monophosphate (cAMP) can elicit distinct functional responses in cardiac myocytes. Selectively sequestering cAMP activity to discrete intracellular microdomains is considered essential for generating receptor-specific responses. The processes that control this aspect of compartmentalized cAMP signaling, however, are not completely clear. Over the years, technological innovations have provided critical breakthroughs in advancing our understanding of the mechanisms underlying cAMP compartmentation. Some of the factors identified include localized production of cAMP by differential distribution of receptors, localized breakdown of this second messenger by targeted distribution of phosphodiesterase enzymes, and limited diffusion of cAMP by protein kinase A (PKA)-dependent buffering or physically restricted barriers. The aim of this review is to provide a discussion of our current knowledge and highlight some of the gaps that still exist in the field of cAMP compartmentation in cardiac myocytes.
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Vinogradova TM, Lakatta EG. Dual Activation of Phosphodiesterase 3 and 4 Regulates Basal Cardiac Pacemaker Function and Beyond. Int J Mol Sci 2021. [PMID: 34445119 DOI: 10.3390/ijms22168414.pmid:34445119;pmcid:pmc8395138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
The sinoatrial (SA) node is the physiological pacemaker of the heart, and resting heart rate in humans is a well-known risk factor for cardiovascular disease and mortality. Consequently, the mechanisms of initiating and regulating the normal spontaneous SA node beating rate are of vital importance. Spontaneous firing of the SA node is generated within sinoatrial nodal cells (SANC), which is regulated by the coupled-clock pacemaker system. Normal spontaneous beating of SANC is driven by a high level of cAMP-mediated PKA-dependent protein phosphorylation, which rely on the balance between high basal cAMP production by adenylyl cyclases and high basal cAMP degradation by cyclic nucleotide phosphodiesterases (PDEs). This diverse class of enzymes includes 11 families and PDE3 and PDE4 families dominate in both the SA node and cardiac myocardium, degrading cAMP and, consequently, regulating basal cardiac pacemaker function and excitation-contraction coupling. In this review, we will demonstrate similarities between expression, distribution, and colocalization of various PDE subtypes in SANC and cardiac myocytes of different species, including humans, focusing on PDE3 and PDE4. Here, we will describe specific targets of the coupled-clock pacemaker system modulated by dual PDE3 + PDE4 activation and provide evidence that concurrent activation of PDE3 + PDE4, operating in a synergistic manner, regulates the basal cardiac pacemaker function and provides control over normal spontaneous beating of SANCs through (PDE3 + PDE4)-dependent modulation of local subsarcolemmal Ca2+ releases (LCRs).
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Affiliation(s)
- Tatiana M Vinogradova
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institute of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institute of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
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Dual Activation of Phosphodiesterase 3 and 4 Regulates Basal Cardiac Pacemaker Function and Beyond. Int J Mol Sci 2021; 22:ijms22168414. [PMID: 34445119 PMCID: PMC8395138 DOI: 10.3390/ijms22168414] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/01/2021] [Accepted: 08/02/2021] [Indexed: 11/17/2022] Open
Abstract
The sinoatrial (SA) node is the physiological pacemaker of the heart, and resting heart rate in humans is a well-known risk factor for cardiovascular disease and mortality. Consequently, the mechanisms of initiating and regulating the normal spontaneous SA node beating rate are of vital importance. Spontaneous firing of the SA node is generated within sinoatrial nodal cells (SANC), which is regulated by the coupled-clock pacemaker system. Normal spontaneous beating of SANC is driven by a high level of cAMP-mediated PKA-dependent protein phosphorylation, which rely on the balance between high basal cAMP production by adenylyl cyclases and high basal cAMP degradation by cyclic nucleotide phosphodiesterases (PDEs). This diverse class of enzymes includes 11 families and PDE3 and PDE4 families dominate in both the SA node and cardiac myocardium, degrading cAMP and, consequently, regulating basal cardiac pacemaker function and excitation-contraction coupling. In this review, we will demonstrate similarities between expression, distribution, and colocalization of various PDE subtypes in SANC and cardiac myocytes of different species, including humans, focusing on PDE3 and PDE4. Here, we will describe specific targets of the coupled-clock pacemaker system modulated by dual PDE3 + PDE4 activation and provide evidence that concurrent activation of PDE3 + PDE4, operating in a synergistic manner, regulates the basal cardiac pacemaker function and provides control over normal spontaneous beating of SANCs through (PDE3 + PDE4)-dependent modulation of local subsarcolemmal Ca2+ releases (LCRs).
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Pericardial NT-Pro-BNP and GDF-15 as Biomarkers of Atrial Fibrillation and Atrial Matrix Remodeling in Aortic Stenosis. Diagnostics (Basel) 2021; 11:diagnostics11081422. [PMID: 34441356 PMCID: PMC8392313 DOI: 10.3390/diagnostics11081422] [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: 07/01/2021] [Revised: 07/17/2021] [Accepted: 08/03/2021] [Indexed: 12/11/2022] Open
Abstract
Aims: This study aimed to evaluate the association of GDF-15 and NT-pro-BNP in two different biological matrices with AF in severe aortic stenosis patients undergoing aortic valve replacement surgery (AVR), its association with atrial matrix remodeling, as well as with 30-day postoperative outcomes. Main Methods: One hundred and twenty-six patients between 2009 and 2019 with severe aortic stenosis undergoing AVR surgery in a tertiary hospital were assessed. Key Findings: pericardial fluid GDF-15 and pericardial fluid and serum NT-pro-BNP were increased in AF patients with aortic stenosis. COL1A1 and COL3A1 gene expression increased when pericardial fluid NT-pro-BNP values were higher. TIMP4 was positively correlated with pericardial fluid GDF-15. Significance: GDF-15 and NT-pro-BNP in the pericardial fluid are biomarkers of atrial fibrillation in aortic stenosis and correlate with atrial matrix remodeling. AKI is predicted by both serum and pericardial fluid GDF-15.
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Mika D, Fischmeister R. Cyclic nucleotide signaling and pacemaker activity. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:29-38. [PMID: 34298001 DOI: 10.1016/j.pbiomolbio.2021.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 06/21/2021] [Accepted: 07/13/2021] [Indexed: 01/01/2023]
Abstract
The sinoatrial node (SAN) is the natural pacemaker of the heart, producing the electrical impulse that initiates every heart beat. Its activity is tightly controlled by the autonomic nervous system, and by circulating and locally released factors. Neurohumoral regulation of heart rate plays a crucial role in the integration of vital functions and influences behavior and ability to respond to changing environmental conditions. At the cellular level, modulation of SAN activity occurs through intracellular signaling pathways involving cyclic nucleotides: cyclic AMP (cAMP) and cyclic GMP (cGMP). In this Review, dedicated to Professor Dario DiFrancesco and his accomplishements in the field of cardiac pacemaking, we summarize all findings on the role of cyclic nucleotides signaling in regulating the key actors of cardiac automatism, and we provide an up-to-date review on cAMP- and cGMP-phosphodiesterases (PDEs), compellingly involved in this modulation.
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Affiliation(s)
- Delphine Mika
- Université Paris-Saclay, Inserm, UMR-S, 1180, Châtenay-Malabry, France.
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9
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Dorey TW, Mackasey M, Jansen HJ, McRae MD, Bohne LJ, Liu Y, Belke DD, Atkinson L, Rose RA. Natriuretic peptide receptor B maintains heart rate and sinoatrial node function via cyclic GMP-mediated signaling. Cardiovasc Res 2021; 118:1917-1931. [PMID: 34273155 DOI: 10.1093/cvr/cvab245] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 07/16/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Heart rate (HR) is a critical indicator of cardiac performance that is determined by sinoatrial node (SAN) function and regulation. Natriuretic peptides, including C-type NP (CNP) have been shown to modulate ion channel function in the SAN when applied exogenously. CNP is the only NP that acts as a ligand for natriuretic peptide receptor-B (NPR-B). Despite these properties, the ability of CNP and NPR-B to regulate HR and intrinsic SAN automaticity in vivo, and the mechanisms by which it does so, are incompletely understood. Thus, the objective of this study was to determine the role of NPR-B signaling in regulating HR and SAN function. METHODS AND RESULTS We have used NPR-B deficient mice (NPR-B+/-) to study HR regulation and SAN function using telemetry in conscious mice, intracardiac electrophysiology in anesthetized mice, high resolution optical mapping in isolated SAN preparations, patch-clamping in isolated SAN myocytes, and molecular biology in isolated SAN tissue. These studies demonstrate that NPR-B+/- mice exhibit slow HR, increased corrected SAN recovery time, and slowed SAN conduction. Spontaneous AP firing frequency in isolated SAN myocytes was impaired in NPR-B+/- mice due to reductions in the hyperpolarization activated current (If) and L-type Ca2+ current (ICa,L). If and ICa,L were reduced due to lower cGMP levels and increased hydrolysis of cAMP by phosphodiesterase 3 (PDE3) in the SAN. Inhibiting PDE3 or restoring cGMP signaling via application of 8-Br-cGMP abolished the reductions in cAMP, AP firing, If, and ICa,L, and normalized SAN conduction, in the SAN in NPR-B+/- mice. NPR-B+/- mice did not exhibit changes in SAN fibrosis and showed no evidence of cardiac hypertrophy or changes in ventricular function. CONCLUSIONS NPR-B plays an essential physiological role in maintaining normal HR and SAN function by modulating ion channel function in SAN myocytes via a cGMP/PDE3/cAMP signaling mechanism.
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Affiliation(s)
- Tristan W Dorey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Martin Mackasey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Megan D McRae
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Loryn J Bohne
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Yingjie Liu
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Logan Atkinson
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Jøns C, Porta-Sánchez A, Lai PFH, Wauchop M, Massé S, Azam MA, Asta J, Rose RA, Nanthakumar K. Mechanism of and strategy to mitigate liraglutide-mediated positive chronotropy. Life Sci 2021; 282:119815. [PMID: 34256040 DOI: 10.1016/j.lfs.2021.119815] [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: 04/14/2021] [Revised: 06/25/2021] [Accepted: 07/05/2021] [Indexed: 11/18/2022]
Abstract
AIM An adverse side-effect of Liraglutide (LG), a Glucagon-Like Peptide 1 (GLP1)-analog commonly used in treatments for diabetes, is positive chronotropy. The goal of this study is to investigate on the mechanism of this drug-induced chronotropy and explore potential means to mitigate this side-effect so as to maximize the therapeutic benefits from LG. MAIN METHODS Experiments were conducted with: 1) Isolated rabbit hearts in a Langendorff set-up to assess for direct effects of drug actions and 2) Murine cardiomyocytes isolated from the sino-atrial node (SAN) to assess the effects of LG on spontaneous action potential (AP) firing and the hyperpolarization-activated current If. KEY FINDINGS LG induced a dose-dependent increase in heart rate. Its effects on sinus node automaticity, which were not suppressed during β-blockade with Propranolol, were abolished by If blockade with Ivabradine. In isolated murine SAN myocytes, LG increased spontaneous AP firing frequency by an increase in diastolic depolarization slope without changing other electrophysiological parameters. SIGNIFICANCE LG-induced positive chronotropy is partly due to a direct effect on the SAN and is independent of the adrenergic cascade and extrinsic autonomic reflex mechanisms. The direct LG-associated increase in heart rate should be mitigated with If blockers rather than β-blockade.
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Affiliation(s)
- Christian Jøns
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada; Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen, Denmark
| | - Andreu Porta-Sánchez
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada; Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain and Hospital Universitario Quirónsalud, Madrid, Spain
| | - Patrick F H Lai
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Mohammed Ali Azam
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - John Asta
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada.
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11
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Cellular Mechanisms of the Anti-Arrhythmic Effect of Cardiac PDE2 Overexpression. Int J Mol Sci 2021; 22:ijms22094816. [PMID: 34062838 PMCID: PMC8125727 DOI: 10.3390/ijms22094816] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Phosphodiesterases (PDE) critically regulate myocardial cAMP and cGMP levels. PDE2 is stimulated by cGMP to hydrolyze cAMP, mediating a negative crosstalk between both pathways. PDE2 upregulation in heart failure contributes to desensitization to β-adrenergic overstimulation. After isoprenaline (ISO) injections, PDE2 overexpressing mice (PDE2 OE) were protected against ventricular arrhythmia. Here, we investigate the mechanisms underlying the effects of PDE2 OE on susceptibility to arrhythmias. Methods: Cellular arrhythmia, ion currents, and Ca2+-sparks were assessed in ventricular cardiomyocytes from PDE2 OE and WT littermates. Results: Under basal conditions, action potential (AP) morphology were similar in PDE2 OE and WT. ISO stimulation significantly increased the incidence of afterdepolarizations and spontaneous APs in WT, which was markedly reduced in PDE2 OE. The ISO-induced increase in ICaL seen in WT was prevented in PDE2 OE. Moreover, the ISO-induced, Epac- and CaMKII-dependent increase in INaL and Ca2+-spark frequency was blunted in PDE2 OE, while the effect of direct Epac activation was similar in both groups. Finally, PDE2 inhibition facilitated arrhythmic events in ex vivo perfused WT hearts after reperfusion injury. Conclusion: Higher PDE2 abundance protects against ISO-induced cardiac arrhythmia by preventing the Epac- and CaMKII-mediated increases of cellular triggers. Thus, activating myocardial PDE2 may represent a novel intracellular anti-arrhythmic therapeutic strategy in HF.
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12
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Fragão-Marques M, Miranda I, Martins D, Barroso I, Mendes C, Pereira-Neves A, Falcão-Pires I, Leite-Moreira A. Atrial matrix remodeling in atrial fibrillation patients with aortic stenosis. BMC Cardiovasc Disord 2020; 20:468. [PMID: 33129260 PMCID: PMC7603735 DOI: 10.1186/s12872-020-01754-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/25/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND This study aimed to evaluate atrium extracellular matrix remodeling in atrial fibrillation (AF) patients with severe aortic stenosis, through histological fibrosis quantification and extracellular matrix gene expression analysis, as well as serum quantification of selected protein targets. METHODS A posthoc analysis of a prospective study was performed in a cohort of aortic stenosis patients. Between 2014 and 2019, 56 patients with severe aortic stenosis submitted to aortic valve replacement surgery in a tertiary hospital were selected. RESULTS Fibrosis was significantly increased in the AF group when compared to sinus rhythm (SR) patients (p = 0.024). Moreover, cardiomyocyte area was significantly higher in AF patients versus SR patients (p = 0.008). Conversely, collagen III gene expression was increased in AF patients (p = 0.038). TIMP1 was less expressed in the atria of AF patients. MMP16/TIMP4 ratio was significantly decreased in AF patients (p = 0.006). TIMP1 (p = 0.004) and TIMP2 (p = 0.012) were significantly increased in the serum of AF patients. Aortic valve maximum (p = 0.0159) and mean (p = 0.031) gradients demonstrated a negative association with serum TIMP1. CONCLUSIONS Atrial fibrillation patients with severe aortic stenosis present increased atrial fibrosis and collagen type III synthesis, with extracellular matrix remodelling demonstrated by a decrease in the MMP16/TIMP4 ratio, along with an increased serum TIMP1 and TIMP2 proteins.
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Affiliation(s)
- Mariana Fragão-Marques
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal.
- Department of Clinical Pathology, São João University Hospital Centre, Porto, Portugal.
| | - I Miranda
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal
| | - D Martins
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal
| | - I Barroso
- Department of Clinical Pathology, São João University Hospital Centre, Porto, Portugal
- EPIUnit, Instituto de Saúde Pública, University of Porto, Porto, Portugal
| | - C Mendes
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal
| | - A Pereira-Neves
- Department of Biomedicine, Unit of Anatomy, Faculty of Medicine, University of Porto, Porto, Portugal
| | - I Falcão-Pires
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal
| | - A Leite-Moreira
- Cardiovascular Research and Development Center, Faculty of Medicine, University of Porto, Alameda Professor Hernani Monteiro, 4200, Porto, Portugal
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13
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Age-Dependent Maturation of iPSC-CMs Leads to the Enhanced Compartmentation of β 2AR-cAMP Signalling. Cells 2020; 9:cells9102275. [PMID: 33053822 PMCID: PMC7601768 DOI: 10.3390/cells9102275] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/04/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022] Open
Abstract
The ability to differentiate induced-pluripotent stem cells into cardiomyocytes (iPSC-CMs) has opened up novel avenues for potential cardiac therapies. However, iPSC-CMs exhibit a range of somewhat immature functional properties. This study explored the development of the beta-adrenergic receptor (βAR) pathway, which is crucial in regulating contraction and signifying the health and maturity of myocytes. We explored the compartmentation of β2AR-signalling and phosphodiesterases (PDEs) in caveolae, as functional nanodomains supporting the mature phenotype. Förster Resonance Energy Transfer (FRET) microscopy was used to study the cyclic adenosine monophosphate (cAMP) levels in iPSC-CMs at day 30, 60, and 90 following βAR subtype-specific stimulation. Subsequently, the PDE2, PDE3, and PDE4 activity was investigated using specific inhibitors. Cells were treated with methyl-β-cyclodextrin (MβCD) to remove cholesterol as a method of decompartmentalising β2AR. As iPSC-CMs mature with a prolonged culture time, the caveolae density is increased, leading to a reduction in the overall cytoplasmic cAMP signal stimulated through β2AR (but not β1AR). Pan-phosphodiesterase inhibition or caveolae depletion leads to an increase in the β2AR-stimulated cytoplasmic cAMP. Moreover, with time in culture, the increase in the βAR-dependent cytoplasmic cAMP becomes more sensitive to cholesterol removal. The regulation of the β2AR response by PDE2 and 4 is similarly increased with the time in culture. We conclude that both the β2AR and PDEs are restricted to the caveolae nanodomains, and thereby exhibit a tighter spatial restriction over the cAMP signal in late-stage compared to early iPSC-CMs.
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14
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Sadek MS, Cachorro E, El-Armouche A, Kämmerer S. Therapeutic Implications for PDE2 and cGMP/cAMP Mediated Crosstalk in Cardiovascular Diseases. Int J Mol Sci 2020; 21:E7462. [PMID: 33050419 PMCID: PMC7590001 DOI: 10.3390/ijms21207462] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
Phosphodiesterases (PDEs) are the principal superfamily of enzymes responsible for degrading the secondary messengers 3',5'-cyclic nucleotides cAMP and cGMP. Their refined subcellular localization and substrate specificity contribute to finely regulate cAMP/cGMP gradients in various cellular microdomains. Redistribution of multiple signal compartmentalization components is often perceived under pathological conditions. Thereby PDEs have long been pursued as therapeutic targets in diverse disease conditions including neurological, metabolic, cancer and autoimmune disorders in addition to numerous cardiovascular diseases (CVDs). PDE2 is a unique member of the broad family of PDEs. In addition to its capability to hydrolyze both cAMP and cGMP, PDE2 is the sole isoform that may be allosterically activated by cGMP increasing its cAMP hydrolyzing activity. Within the cardiovascular system, PDE2 serves as an integral regulator for the crosstalk between cAMP/cGMP pathways and thereby may couple chronically adverse augmented cAMP signaling with cardioprotective cGMP signaling. This review provides a comprehensive overview of PDE2 regulatory functions in multiple cellular components within the cardiovascular system and also within various subcellular microdomains. Implications for PDE2- mediated crosstalk mechanisms in diverse cardiovascular pathologies are discussed highlighting the prospective use of PDE2 as a potential therapeutic target in cardiovascular disorders.
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Affiliation(s)
| | | | - Ali El-Armouche
- Department of Pharmacology and Toxicology, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (M.S.S.); (E.C.)
| | - Susanne Kämmerer
- Department of Pharmacology and Toxicology, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (M.S.S.); (E.C.)
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15
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Zhang H, Zhang S, Wang W, Wang K, Shen W. A Mathematical Model of the Mouse Atrial Myocyte With Inter-Atrial Electrophysiological Heterogeneity. Front Physiol 2020; 11:972. [PMID: 32848887 PMCID: PMC7425199 DOI: 10.3389/fphys.2020.00972] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 07/16/2020] [Indexed: 12/20/2022] Open
Abstract
Biophysically detailed mathematical models of cardiac electrophysiology provide an alternative to experimental approaches for investigating possible ionic mechanisms underlying the genesis of electrical action potentials and their propagation through the heart. The aim of this study was to develop a biophysically detailed mathematical model of the action potentials of mouse atrial myocytes, a popular experimental model for elucidating molecular and cellular mechanisms of arrhythmogenesis. Based on experimental data from isolated mouse atrial cardiomyocytes, a set of mathematical equations for describing the biophysical properties of membrane ion channel currents, intracellular Ca2+ handling, and Ca2+-calmodulin activated protein kinase II and β-adrenergic signaling pathways were developed. Wherever possible, membrane ion channel currents were modeled using Markov chain formalisms, allowing detailed representation of channel kinetics. The model also considered heterogeneous electrophysiological properties between the left and the right atrial cardiomyocytes. The developed model was validated by its ability to reproduce the characteristics of action potentials and Ca2+ transients, matching quantitatively to experimental data. Using the model, the functional roles of four K+ channel currents in atrial action potential were evaluated by channel block simulations, results of which were quantitatively in agreement with existent experimental data. To conclude, this newly developed model of mouse atrial cardiomyocytes provides a powerful tool for investigating possible ion channel mechanisms of atrial electrical activity at the cellular level and can be further used to investigate mechanisms underlying atrial arrhythmogenesis.
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Affiliation(s)
- Henggui Zhang
- Department of Physics and Astronomy, Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom.,Peng Cheng Laboratory, Shenzhen, China
| | - Shanzhuo Zhang
- Department of Physics and Astronomy, Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom.,School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Wei Wang
- Department of Physics and Astronomy, Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom.,Peng Cheng Laboratory, Shenzhen, China.,Shenzhen Key Laboratory of Visual Object Detection and Recognition, Harbin Institute of Technology, Shenzhen, China
| | - Kuanquan Wang
- School of Computer Science and Technology, Harbin Institute of Technology, Harbin, China
| | - Weijian Shen
- Department of Physics and Astronomy, Biological Physics Group, School of Physics & Astronomy, The University of Manchester, Manchester, United Kingdom
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16
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Bardsley EN, Paterson DJ. Neurocardiac regulation: from cardiac mechanisms to novel therapeutic approaches. J Physiol 2020; 598:2957-2976. [PMID: 30307615 PMCID: PMC7496613 DOI: 10.1113/jp276962] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiac sympathetic overactivity is a well-established contributor to the progression of neurogenic hypertension and heart failure, yet the underlying pathophysiology remains unclear. Recent studies have highlighted the importance of acutely regulated cyclic nucleotides and their effectors in the control of intracellular calcium and exocytosis. Emerging evidence now suggests that a significant component of sympathetic overactivity and enhanced transmission may arise from impaired cyclic nucleotide signalling, resulting from compromised phosphodiesterase activity, as well as alterations in receptor-coupled G-protein activation. In this review, we address some of the key cellular and molecular pathways that contribute to sympathetic overactivity in hypertension and discuss their potential for therapeutic targeting.
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Affiliation(s)
- E. N. Bardsley
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
| | - D. J. Paterson
- Wellcome Trust OXION Initiative in Ion Channels and DiseaseOxfordUK
- Burdon Sanderson Cardiac Science Centre, Department of PhysiologyAnatomy and Genetics, University of OxfordOxfordOX1 3PTUK
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17
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Arbel-Ganon L, Behar JA, Gómez AM, Yaniv Y. Distinct mechanisms mediate pacemaker dysfunction associated with catecholaminergic polymorphic ventricular tachycardia mutations: Insights from computational modeling. J Mol Cell Cardiol 2020; 143:85-95. [PMID: 32339564 DOI: 10.1016/j.yjmcc.2020.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/09/2020] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a stress-induced ventricular arrhythmia associated with rhythm disturbance and impaired sinoatrial node cell (SANC) automaticity (pauses). Mutations associated with dysfunction of Ca2+-related mechanisms have been shown to be present in CPVT. These dysfunctions include impaired Ca2+ release from the ryanodine receptor (i.e., RyR2R4496C mutation) or binding to calsequestrin 2 (CASQ2). In SANC, Ca2+ signaling directly and indirectly mediates pacemaker function. We address here the following research questions: (i) what coupled-clock mechanisms and pathways mediate pacemaker mutations associated with CPVT in basal and in response to β-adrenergic stimulation? (ii) Can different mechanisms lead to the same CPVT-related pacemaker pauses? (iii) Can the mutation-induced deteriorations in SANC function be reversed by drug intervention or gene manipulation? We used a numerical model of mice SANC that includes membrane and intracellular mechanisms and their interconnected signaling pathways. In the basal state of RyR2R4496C SANC, the model predicted that the Na+-Ca2+ exchanger current (INCX) and T-type Ca2+ current (ICaT) mediate between changes in Ca2+ signaling and SANC dysfunction. Under β-adrenergic stimulation, changes in cAMP-PKA signaling and the sodium currents (INa), in addition to INCX and ICaT, mediate between changes in Ca2+ signaling and SANC automaticity pauses. Under basal conditions in Casq2-/-, the same mechanisms drove changes in Ca2+ signaling and subsequent pacemaker dysfunction. However, SANC automaticity pauses in response to β-AR stimulation were mediated by ICaT and INa. Taken together, distinct mechanisms can lead to CPVT-associated SANC automaticity pauses. In addition, we predict that specifically increasing SANC cAMP-PKA activity by either a pharmacological agent (IBMX, a phosphodiesterase (PDE) inhibitor), gene manipulation (overexpression of adenylyl cyclase 1/8) or direct manipulation of the SERCA phosphorylation target through changes in gene expression, compensate for the impairment in SANC automaticity. These findings suggest new insights for understanding CPVT and its therapeutic approach.
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Affiliation(s)
- Limor Arbel-Ganon
- Laboratory of Bioenergetic and Bioelectric Systems, Biomedical Engineering Faculty, Technion-IIT, Haifa, Israel
| | - Joachim A Behar
- Laboratory of Bioenergetic and Bioelectric Systems, Biomedical Engineering Faculty, Technion-IIT, Haifa, Israel
| | - Ana María Gómez
- Laboratory of Signaling and Cardiovascular Pathophysiology, UMR-S 1180, Inserm, Univ. Paris-Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Yael Yaniv
- Laboratory of Bioenergetic and Bioelectric Systems, Biomedical Engineering Faculty, Technion-IIT, Haifa, Israel.
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18
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New aspects in cardiac L-type Ca2+ channel regulation. Biochem Soc Trans 2020; 48:39-49. [PMID: 32065210 DOI: 10.1042/bst20190229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 12/23/2022]
Abstract
Cardiac excitation-contraction coupling is initiated with the influx of Ca2+ ions across the plasma membrane through voltage-gated L-type calcium channels. This process is tightly regulated by modulation of the channel open probability and channel localization. Protein kinase A (PKA) is found in close association with the channel and is one of the main regulators of its function. Whether this kinase is modulating the channel open probability by phosphorylation of key residues or via alternative mechanisms is unclear. This review summarizes recent findings regarding the PKA-mediated channel modulation and will highlight recently discovered regulatory mechanisms that are independent of PKA activity and involve protein-protein interactions and channel localization.
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19
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MacDonald EA, Rose RA, Quinn TA. Neurohumoral Control of Sinoatrial Node Activity and Heart Rate: Insight From Experimental Models and Findings From Humans. Front Physiol 2020; 11:170. [PMID: 32194439 PMCID: PMC7063087 DOI: 10.3389/fphys.2020.00170] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 02/13/2020] [Indexed: 12/22/2022] Open
Abstract
The sinoatrial node is perhaps one of the most important tissues in the entire body: it is the natural pacemaker of the heart, making it responsible for initiating each-and-every normal heartbeat. As such, its activity is heavily controlled, allowing heart rate to rapidly adapt to changes in physiological demand. Control of sinoatrial node activity, however, is complex, occurring through the autonomic nervous system and various circulating and locally released factors. In this review we discuss the coupled-clock pacemaker system and how its manipulation by neurohumoral signaling alters heart rate, considering the multitude of canonical and non-canonical agents that are known to modulate sinoatrial node activity. For each, we discuss the principal receptors involved and known intracellular signaling and protein targets, highlighting gaps in our knowledge and understanding from experimental models and human studies that represent areas for future research.
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Affiliation(s)
- Eilidh A. MacDonald
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Robert A. Rose
- Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - T. Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
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20
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Asfaw TN, Tyan L, Glukhov AV, Bondarenko VE. A compartmentalized mathematical model of mouse atrial myocytes. Am J Physiol Heart Circ Physiol 2020; 318:H485-H507. [PMID: 31951471 DOI: 10.1152/ajpheart.00460.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Various experimental mouse models are extensively used to research human diseases, including atrial fibrillation, the most common cardiac rhythm disorder. Despite this, there are no comprehensive mathematical models that describe the complex behavior of the action potential and [Ca2+]i transients in mouse atrial myocytes. Here, we develop a novel compartmentalized mathematical model of mouse atrial myocytes that combines the action potential, [Ca2+]i dynamics, and β-adrenergic signaling cascade for a subpopulation of right atrial myocytes with developed transverse-axial tubule system. The model consists of three compartments related to β-adrenergic signaling (caveolae, extracaveolae, and cytosol) and employs local control of Ca2+ release. It also simulates ionic mechanisms of action potential generation and describes atrial-specific Ca2+ handling as well as frequency dependences of the action potential and [Ca2+]i transients. The model showed that the T-type Ca2+ current significantly affects the later stage of the action potential, with little effect on [Ca2+]i transients. The block of the small-conductance Ca2+-activated K+ current leads to a prolongation of the action potential at high intracellular Ca2+. Simulation results obtained from the atrial model cells were compared with those from ventricular myocytes. The developed model represents a useful tool to study complex electrical properties in the mouse atria and could be applied to enhance the understanding of atrial physiology and arrhythmogenesis.NEW & NOTEWORTHY A new compartmentalized mathematical model of mouse right atrial myocytes was developed. The model simulated action potential and Ca2+ dynamics at baseline and after stimulation of the β-adrenergic signaling system. Simulations showed that the T-type Ca2+ current markedly prolonged the later stage of atrial action potential repolarization, with a minor effect on [Ca2+]i transients. The small-conductance Ca2+-activated K+ current block resulted in prolongation of the action potential only at the relatively high intracellular Ca2+.
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Affiliation(s)
- Tesfaye Negash Asfaw
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia
| | - Leonid Tyan
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Alexey V Glukhov
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Vladimir E Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia.,Neuroscience Institute, Georgia State University, Atlanta, Georgia
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21
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Vinogradova TM, Sirenko S, Lukyanenko YO, Yang D, Tarasov KV, Lyashkov AE, Varghese NJ, Li Y, Chakir K, Ziman B, Lakatta EG. Basal Spontaneous Firing of Rabbit Sinoatrial Node Cells Is Regulated by Dual Activation of PDEs (Phosphodiesterases) 3 and 4. Circ Arrhythm Electrophysiol 2019; 11:e005896. [PMID: 29880528 DOI: 10.1161/circep.117.005896] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 03/27/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Spontaneous firing of sinoatrial node cells (SANCs) is regulated by cAMP-mediated, PKA (protein kinase A)-dependent (cAMP/PKA) local subsarcolemmal Ca2+ releases (LCRs) from RyRs (ryanodine receptors). LCRs occur during diastolic depolarization and activate an inward Na+/Ca2+ exchange current that accelerates diastolic depolarization rate prompting the next action potential. PDEs (phosphodiesterases) regulate cAMP-mediated signaling; PDE3/PDE4 represent major PDE activities in SANC, but how they modulate LCRs and basal spontaneous SANC firing remains unknown. METHODS Real-time polymerase chain reaction, Western blot, immunostaining, cellular perforated patch clamping, and confocal microscopy were used to elucidate mechanisms of PDE-dependent regulation of cardiac pacemaking. RESULTS PDE3A, PDE4B, and PDE4D were the major PDE subtypes expressed in rabbit SANC, and PDE3A was colocalized with α-actinin, PDE4D, SERCA (sarcoplasmic reticulum Ca2+ ATP-ase), and PLB (phospholamban) in Z-lines. Inhibition of PDE3 (cilostamide) or PDE4 (rolipram) alone increased spontaneous SANC firing by ≈20% (P<0.05) and ≈5% (P>0.05), respectively, but concurrent PDE3+PDE4 inhibition increased spontaneous firing by ≈45% (P<0.01), indicating synergistic effect. Inhibition of PDE3 or PDE4 alone increased L-type Ca2+ current (ICa,L) by ≈60% (P<0.01) or ≈5% (P>0.05), respectively, and PLB phosphorylation by ≈20% (P>0.05) each, but dual PDE3+PDE4 inhibition increased ICa,L by ≈100% (P<0.01) and PLB phosphorylation by ≈110% (P<0.05). Dual PDE3+PDE4 inhibition increased the LCR number and size (P<0.01) and reduced the SR (sarcoplasmic reticulum) Ca2+ refilling time (P<0.01) and the LCR period (time from action potential-induced Ca2+ transient to subsequent LCR; P<0.01), leading to decrease in spontaneous SANC cycle length (P<0.01). When RyRs were disabled by ryanodine and LCRs ceased, dual PDE3+PDE4 inhibition failed to increase spontaneous SANC firing. CONCLUSIONS Basal cardiac pacemaker function is regulated by concurrent PDE3+PDE4 activation which operates in a synergistic manner via decrease in cAMP/PKA phosphorylation, suppression of LCR parameters, and prolongation of the LCR period and spontaneous SANC cycle length.
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Affiliation(s)
- Tatiana M Vinogradova
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD.
| | - Syevda Sirenko
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Yevgeniya O Lukyanenko
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Dongmei Yang
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Kirill V Tarasov
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Alexey E Lyashkov
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Nevin J Varghese
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Yue Li
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Khalid Chakir
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Bruce Ziman
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD
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22
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Swan AH, Gruscheski L, Boland LA, Brand T. The Popeye domain containing gene family encoding a family of cAMP-effector proteins with important functions in striated muscle and beyond. J Muscle Res Cell Motil 2019; 40:169-183. [PMID: 31197601 PMCID: PMC6726836 DOI: 10.1007/s10974-019-09523-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 06/11/2019] [Indexed: 12/14/2022]
Abstract
The Popeye domain containing (POPDC) gene family encodes a novel class of membrane-bound cyclic AMP effector proteins. POPDC proteins are abundantly expressed in cardiac and skeletal muscle. Consistent with its predominant expression in striated muscle, Popdc1 and Popdc2 null mutants in mouse and zebrafish develop cardiac arrhythmia and muscular dystrophy. Likewise, mutations in POPDC genes in patients have been associated with cardiac arrhythmia and muscular dystrophy phenotypes. A membrane trafficking function has been identified in this context. POPDC proteins have also been linked to tumour formation. Here, POPDC1 plays a role as a tumour suppressor by limiting c-Myc and WNT signalling. Currently, a common functional link between POPDC's role in striated muscle and as a tumour suppressor is lacking. We also discuss several alternative working models to better understand POPDC protein function.
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Affiliation(s)
- Alexander H Swan
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK
- Institute of Chemical Biology, Imperial College London, London, UK
| | - Lena Gruscheski
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK
| | - Lauren A Boland
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK
| | - Thomas Brand
- National Heart and Lung Institute, Imperial College London, 4th Floor ICTEM Building, Du Cane Road, London, W12 0NN, UK.
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Odnoshivkina UG, Sytchev VI, Starostin O, Petrov AM. Brain cholesterol metabolite 24-hydroxycholesterol modulates inotropic responses to β-adrenoceptor stimulation: The role of NO and phosphodiesterase. Life Sci 2019; 220:117-126. [DOI: 10.1016/j.lfs.2019.01.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/22/2019] [Accepted: 01/30/2019] [Indexed: 12/11/2022]
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24
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Derici MK, Sadi G, Cenik B, Güray T, Demirel-Yilmaz E. Differential expressions and functions of phosphodiesterase enzymes in different regions of the rat heart. Eur J Pharmacol 2018; 844:118-129. [PMID: 30529467 DOI: 10.1016/j.ejphar.2018.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 11/29/2018] [Accepted: 12/05/2018] [Indexed: 10/27/2022]
Abstract
Phosphodiesterase enzymes (PDEs) are responsible for the adjustment of cyclic nucleotide levels. Alterations in PDE expressions in different tissues cause conflicts between functional and clinical effects of PDE inhibitors. Therefore, the aim of this study was to investigate the gene and protein expressions and the functional role of PDEs in atrium and ventricle of rat heart. The expressions of PDEs were examined in cardiac intact tissues and enzymatically isolated cells. The effects of PDE1-5 inhibitors (vinpocetine, EHNA, milrinone, rolipram, sildenafil, and IBMX) on basal and isoprenaline-stimulated contractions and sinus rate were recorded in the isolated spontaneously beating right atrium and electrically stimulated left papillary muscles. The mRNA and protein levels of PDEs were significantly different in atrial and ventricular intact tissues and isolated myocytes. Atrial contractions were increased with vinpocetine while suppressed by EHNA, milrinone, rolipram, sildenafil and IBMX. Milrinone, sildenafil and IBMX increased the heart rate whereas vinpocetine caused negative chronotropy. Papillary muscle contractions have been increased only with the vinpocetine and IBMX. Both the expression and the action of PDE-1-5 show atrial and ventricular differences. Therefore, these differences should be taken into account in the experimental or therapeutic approaches of the heart.
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Affiliation(s)
- Mehmet Kürşat Derici
- Faculty of Medicine, Department of Medical Pharmacology, Kirikkale University, Yahsihan, Kirikkale, Turkey.
| | - Gökhan Sadi
- Faculty of Arts and Sciences, Department of Biological Sciences, Karamanoglu Mehmetbey University, Karaman, Turkey
| | - Başar Cenik
- Faculty of Medicine, Department of Medical Pharmacology, Ankara University, Ankara, Turkey
| | - Tülin Güray
- Faculty of Arts and Sciences, Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
| | - Emine Demirel-Yilmaz
- Faculty of Medicine, Department of Medical Pharmacology, Ankara University, Ankara, Turkey
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25
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Lang D, Glukhov AV. Functional Microdomains in Heart's Pacemaker: A Step Beyond Classical Electrophysiology and Remodeling. Front Physiol 2018; 9:1686. [PMID: 30538641 PMCID: PMC6277479 DOI: 10.3389/fphys.2018.01686] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/09/2018] [Indexed: 12/12/2022] Open
Abstract
Spontaneous beating of the sinoatrial node (SAN), the primary pacemaker of the heart, is initiated, sustained, and regulated by a complex system that integrates ion channels and transporters on the cell membrane surface (often referred to as "membrane clock") with subcellular calcium handling machinery (by parity of reasoning referred to as an intracellular "Ca2+ clock"). Stable, rhythmic beating of the SAN is ensured by a rigorous synchronization between these two clocks highlighted in the coupled-clock system concept of SAN timekeeping. The emerging results demonstrate that such synchronization of the complex pacemaking machinery at the cellular level depends on tightly regulated spatiotemporal signals which are restricted to precise sub-cellular microdomains and associated with discrete clusters of different ion channels, transporters, and regulatory receptors. It has recently become evident that within the microdomains, various proteins form an interacting network and work together as a part of a macromolecular signaling complex. These protein-protein interactions are tightly controlled and regulated by a variety of neurohormonal signaling pathways and the diversity of cellular responses achieved with a limited pool of second messengers is made possible through the organization of essential signal components in particular microdomains. In this review, we highlight the emerging understanding of the functionality of distinct subcellular microdomains in SAN myocytes and their functional role in the accumulation and neurohormonal regulation of proteins involved in cardiac pacemaking. We also demonstrate how changes in scaffolding proteins may lead to microdomain-targeted remodeling and regulation of pacemaker proteins contributing to SAN dysfunction.
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Affiliation(s)
- Di Lang
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Alexey V Glukhov
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
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26
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Vinogradova TM, Kobrinsky E, Lakatta EG. Dual Activation of Phosphodiesterases 3 and 4 Regulates Basal Spontaneous Beating Rate of Cardiac Pacemaker Cells: Role of Compartmentalization? Front Physiol 2018; 9:1301. [PMID: 30356755 PMCID: PMC6189467 DOI: 10.3389/fphys.2018.01301] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/29/2018] [Indexed: 12/17/2022] Open
Abstract
Spontaneous firing of sinoatrial (SA) node cells (SANCs) is regulated by cyclic adenosine monophosphate (cAMP)-mediated, protein kinase A (PKA)-dependent (cAMP/PKA) local subsarcolemmal Ca2+ releases (LCRs) from ryanodine receptors (RyR). The LCRs occur during diastolic depolarization (DD) and activate an inward Na+/Ca2+ exchange current that accelerates the DD rate prompting the next action potential (AP). Basal phosphodiesterases (PDEs) activation degrades cAMP, reduces basal cAMP/PKA-dependent phosphorylation, and suppresses normal spontaneous firing of SANCs. The cAMP-degrading PDE1, PDE3, and PDE4 represent major PDE activities in rabbit SANC, and PDE inhibition by 3-isobutyl-1-methylxanthine (IBMX) increases spontaneous firing of SANC by ∼50%. Though inhibition of single PDE1–PDE4 only moderately increases spontaneous SANC firing, dual PDE3 + PDE4 inhibition produces a synergistic effect hastening the spontaneous SANC beating rate by ∼50%. Here, we describe the expression and distribution of different PDE subtypes within rabbit SANCs, several specific targets (L-type Ca2+ channels and phospholamban) regulated by basal concurrent PDE3 + PDE4 activation, and critical importance of RyR Ca2+ releases for PDE-dependent regulation of spontaneous SANC firing. Colocalization of PDE3 and PDE4 beneath sarcolemma or in striated patterns inside SANCs strongly suggests that PDE-dependent regulation of cAMP/PKA signaling might be executed at the local level; this idea, however, requires further verification.
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Affiliation(s)
- Tatiana M Vinogradova
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
| | - Evgeny Kobrinsky
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, Intramural Research Program, NIA, NIH, Baltimore, MD, United States
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27
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Bhogal NK, Hasan A, Gorelik J. The Development of Compartmentation of cAMP Signaling in Cardiomyocytes: The Role of T-Tubules and Caveolae Microdomains. J Cardiovasc Dev Dis 2018; 5:jcdd5020025. [PMID: 29751502 PMCID: PMC6023514 DOI: 10.3390/jcdd5020025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/18/2018] [Accepted: 04/28/2018] [Indexed: 12/26/2022] Open
Abstract
3′-5′-cyclic adenosine monophosphate (cAMP) is a signaling messenger produced in response to the stimulation of cellular receptors, and has a myriad of functional applications depending on the cell type. In the heart, cAMP is responsible for regulating the contraction rate and force; however, cAMP is also involved in multiple other functions. Compartmentation of cAMP production may explain the specificity of signaling following a stimulus. In particular, transverse tubules (T-tubules) and caveolae have been found to be critical structural components for the spatial confinement of cAMP in cardiomyocytes, as exemplified by beta-adrenergic receptor (β-ARs) signaling. Pathological alterations in cardiomyocyte microdomain architecture led to a disruption in compartmentation of the cAMP signal. In this review, we discuss the difference between atrial and ventricular cardiomyocytes in respect to microdomain organization, and the pathological changes of atrial and ventricular cAMP signaling in response to myocyte dedifferentiation. In addition, we review the role of localized phosphodiesterase (PDE) activity in constraining the cAMP signal. Finally, we discuss microdomain biogenesis and maturation of cAMP signaling with the help of induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Understanding these mechanisms may help to overcome the detrimental effects of pathological structural remodeling.
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Affiliation(s)
- Navneet K Bhogal
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, London W12 0NN, UK.
| | - Alveera Hasan
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, London W12 0NN, UK.
| | - Julia Gorelik
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, London W12 0NN, UK.
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28
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Galindo-Tovar A, Vargas ML, Kaumann AJ. Phosphodiesterase PDE2 activity, increased by isoprenaline, does not reduce β-adrenoceptor-mediated chronotropic and inotropic effects in rat heart. Naunyn Schmiedebergs Arch Pharmacol 2018; 391:571-585. [PMID: 29556684 DOI: 10.1007/s00210-018-1480-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 02/13/2018] [Indexed: 12/12/2022]
Abstract
Myocardial PDE2 activity increases in terminal human heart failure and after isoprenaline infusion in rat heart. PDE2 inhibitors do not potentiate the murine sinoatrial tachycardia produced by noradrenaline. We investigated whether isoprenaline infusion induces PDE2 to decrease the chronotropic and inotropic effects of catecholamines in rat heart. Sprague-Dawley rats were infused with isoprenaline (2.4 mg kg-1 day-1) for 3 days. We used spontaneously beating right atria, paced right ventricular strips and left ventricular papillary muscles. The effects of the PDE2 inhibitors EHNA (10 μM) and Bay 60-7550 (0.1-1 μM) were investigated on the cardiostimulation produced by noradrenaline (ICI118551 50 nM present to block β2-adrenoceptors) and adrenaline (CGP20712A 300 nM present to block β1-adrenoceptors). Hydrolysis of cAMP by PDE2 was measured by radioenzyme assay. Bay 60-7550 but not EHNA increased sinoatrial beating. A stable tachycardia elicited by noradrenaline (10 nM) or adrenaline (1 μM) was not increased by the PDE2 inhibitors. Isoprenaline infusion increased the hydrolytic PDE2 activity threefold in left ventricle, reduced the chronotropic and inotropic effects and potency of noradrenaline and abolished the effects of adrenaline. The potency of the catecholamines was not increased by the PDE2 inhibitors. Neither EHNA nor Bay 60-7550 potentiated the effects of the catecholamines. Rat PDE2 decreased basal sinoatrial beating but did not reduce the sinoatrial tachycardia or increases of ventricular force mediated through β1- and β2-adrenoceptors. The β-adrenoceptor desensitization induced by the isoprenaline infusion was not reversed by the PDE2 inhibitors despite the increased hydrolysis of cAMP by PDE2.
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Affiliation(s)
- Alejandro Galindo-Tovar
- Grado en Farmacia, Facultad Ciencias de la Salud, Universidad Católica San Antonio de Murcia, 30107, Murcia, Spain
| | - María Luisa Vargas
- Departamento de Farmacología, Facultad de Medicina, Universidad de Murcia, Campus de Espinardo, 30100, Murcia, Spain
| | - Alberto J Kaumann
- Departamento de Farmacología, Facultad de Medicina, Universidad de Murcia, Campus de Espinardo, 30100, Murcia, Spain.
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29
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Parks RJ, Bogachev O, Mackasey M, Ray G, Rose RA, Howlett SE. The impact of ovariectomy on cardiac excitation-contraction coupling is mediated through cAMP/PKA-dependent mechanisms. J Mol Cell Cardiol 2017; 111:51-60. [PMID: 28778766 DOI: 10.1016/j.yjmcc.2017.07.118] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/11/2017] [Accepted: 07/28/2017] [Indexed: 12/18/2022]
Abstract
Ovariectomy (OVX) promotes sarcoplasmic reticulum (SR) Ca2+ overload in ventricular myocytes. We hypothesized that the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway contributes to this Ca2+ dysregulation. Myocytes were isolated from adult female C57BL/6 mice following either OVX or sham surgery (surgery at ≈1mos). Contractions, Ca2+ concentrations (fura-2) and ionic currents were measured simultaneously (37°C, 2Hz) in voltage-clamped myocytes. Intracellular cAMP levels were determined with an enzyme immunoassay; phosphodiesterase (PDE) and adenylyl cyclase (AC) isoform expression was examined with qPCR. Ca2+ currents were similar in myocytes from sham and OVX mice but Ca2+ transients, excitation-contraction (EC)-coupling gain, SR content and contractions were larger in OVX than sham cells. To determine if the cAMP/PKA pathway mediated OVX-induced alterations in EC-coupling, cardiomyocytes were incubated with the PKA inhibitor H-89 (2μM), which abolished baseline differences. While basal intracellular cAMP did not differ, levels were higher in OVX than sham in the presence of a non-selective PDE inhibitor (300μM IBMX), or an AC activator (10μM forskolin). This suggests the production of cAMP by AC and its breakdown by PDE were enhanced by OVX. Consistent with this, mRNA levels for both AC5 and PDE4A were higher in OVX in comparison to sham. Differences in Ca2+ homeostasis and contractions were abolished when sham and OVX cells were dialyzed with patch pipettes containing the same concentration of 8-bromoadenosine-cAMP (50μM). Interestingly, selective inhibition of PDE4 increased Ca2+ current only in OVX cells. Together, these findings suggest that estrogen suppresses SR Ca2+ release and that this is regulated, at least in part, by the cAMP/PKA pathway. These changes in the cAMP/PKA pathway may promote Ca2+ dysregulation and cardiovascular disease when ovarian estrogen levels fall. These results advance our understanding of female-specific cardiomyocyte mechanisms that may affect responses to therapeutic interventions in older women.
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Affiliation(s)
- Randi J Parks
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Oleg Bogachev
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Martin Mackasey
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Gibanananda Ray
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Robert A Rose
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Susan E Howlett
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada; Department of Medicine (Geriatric Medicine), Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
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30
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Phosphodiesterases 3 and 4 Differentially Regulate the Funny Current, I f, in Mouse Sinoatrial Node Myocytes. J Cardiovasc Dev Dis 2017; 4. [PMID: 28868308 PMCID: PMC5573264 DOI: 10.3390/jcdd4030010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cardiac pacemaking, at rest and during the sympathetic fight-or-flight response, depends on cAMP (3',5'-cyclic adenosine monophosphate) signaling in sinoatrial node myocytes (SAMs). The cardiac "funny current" (If) is among the cAMP-sensitive effectors that drive pacemaking in SAMs. If is produced by hyperpolarization-activated, cyclic nucleotide-sensitive (HCN) channels. Voltage-dependent gating of HCN channels is potentiated by cAMP, which acts either by binding directly to the channels or by activating the cAMP-dependent protein kinase (PKA), which phosphorylates them. PKA activity is required for signaling between β adrenergic receptors (βARs) and HCN channels in SAMs but the mechanism that constrains cAMP signaling to a PKA-dependent pathway is unknown. Phosphodiesterases (PDEs) hydrolyze cAMP and form cAMP signaling domains in other types of cardiomyocytes. Here we examine the role of PDEs in regulation of If in SAMs. If was recorded in whole-cell voltage-clamp experiments from acutely-isolated mouse SAMs in the absence or presence of PDE and PKA inhibitors, and before and after βAR stimulation. General PDE inhibition caused a PKA-independent depolarizing shift in the midpoint activation voltage (V1/2) of If at rest and removed the requirement for PKA in βAR-to-HCN signaling. PDE4 inhibition produced a similar PKA-independent depolarizing shift in the V1/2 of If at rest, but did not remove the requirement for PKA in βAR-to-HCN signaling. PDE3 inhibition produced PKA-dependent changes in If both at rest and in response to βAR stimulation. Our results suggest that PDE3 and PDE4 isoforms create distinct cAMP signaling domains that differentially constrain access of cAMP to HCN channels and establish the requirement for PKA in signaling between βARs and HCN channels in SAMs.
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31
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Monterisi S, Lobo MJ, Livie C, Castle JC, Weinberger M, Baillie G, Surdo NC, Musheshe N, Stangherlin A, Gottlieb E, Maizels R, Bortolozzi M, Micaroni M, Zaccolo M. PDE2A2 regulates mitochondria morphology and apoptotic cell death via local modulation of cAMP/PKA signalling. eLife 2017; 6:e21374. [PMID: 28463107 PMCID: PMC5423767 DOI: 10.7554/elife.21374] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 04/29/2017] [Indexed: 01/31/2023] Open
Abstract
cAMP/PKA signalling is compartmentalised with tight spatial and temporal control of signal propagation underpinning specificity of response. The cAMP-degrading enzymes, phosphodiesterases (PDEs), localise to specific subcellular domains within which they control local cAMP levels and are key regulators of signal compartmentalisation. Several components of the cAMP/PKA cascade are located to different mitochondrial sub-compartments, suggesting the presence of multiple cAMP/PKA signalling domains within the organelle. The function and regulation of these domains remain largely unknown. Here, we describe a novel cAMP/PKA signalling domain localised at mitochondrial membranes and regulated by PDE2A2. Using pharmacological and genetic approaches combined with real-time FRET imaging and high resolution microscopy, we demonstrate that in rat cardiac myocytes and other cell types mitochondrial PDE2A2 regulates local cAMP levels and PKA-dependent phosphorylation of Drp1. We further demonstrate that inhibition of PDE2A, by enhancing the hormone-dependent cAMP response locally, affects mitochondria dynamics and protects from apoptotic cell death.
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Affiliation(s)
- Stefania Monterisi
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Miguel J Lobo
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Craig Livie
- Institute of Neuroscioence and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - John C Castle
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Michael Weinberger
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - George Baillie
- Institute of Cardiovascular and Medical Science, University of Glasgow, Glasgow, United Kingdom
| | - Nicoletta C Surdo
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Nshunge Musheshe
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands
| | - Alessandra Stangherlin
- Institute of Neuroscioence and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Eyal Gottlieb
- Beatson Institute, University of Glasgow, Glasgow, United Kingdom
| | - Rory Maizels
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Mario Bortolozzi
- Department of Physics and Astronomy “G. Galilei”, University of Padova, Padova, Italy
- Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy
| | - Massimo Micaroni
- Swedish National Centre for Cellular Imaging, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Manuela Zaccolo
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- BHF Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
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32
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Atrial structure, function and arrhythmogenesis in aged and frail mice. Sci Rep 2017; 7:44336. [PMID: 28290548 PMCID: PMC5349540 DOI: 10.1038/srep44336] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/07/2017] [Indexed: 01/01/2023] Open
Abstract
Atrial fibrillation (AF) is prevalent in aging populations; however not all individuals age at the same rate. Instead, individuals of the same chronological age can vary in health status from fit to frail. Our objective was to determine the impacts of age and frailty on atrial function and arrhythmogenesis in mice using a frailty index (FI). Aged mice were more frail and demonstrated longer lasting AF compared to young mice. Consistent with this, aged mice showed longer P wave duration and PR intervals; however, both parameters showed substantial variability suggesting differences in health status among mice of similar chronological age. In agreement with this, P wave duration and PR interval were highly correlated with FI score. High resolution optical mapping of the atria demonstrated reduced conduction velocity and action potential duration in aged hearts that were also graded by FI score. Furthermore, aged mice had increased interstitial fibrosis along with changes in regulators of extracellular matrix remodelling, which also correlated with frailty. These experiments demonstrate that aging results in changes in atrial structure and function that create a substrate for atrial arrhythmias. Importantly, these changes were heterogeneous due to differences in health status, which could be identified using an FI.
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33
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Vettel C, Lindner M, Dewenter M, Lorenz K, Schanbacher C, Riedel M, Lämmle S, Meinecke S, Mason FE, Sossalla S, Geerts A, Hoffmann M, Wunder F, Brunner FJ, Wieland T, Mehel H, Karam S, Lechêne P, Leroy J, Vandecasteele G, Wagner M, Fischmeister R, El-Armouche A. Phosphodiesterase 2 Protects Against Catecholamine-Induced Arrhythmia and Preserves Contractile Function After Myocardial Infarction. Circ Res 2017; 120:120-132. [DOI: 10.1161/circresaha.116.310069] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 10/27/2016] [Accepted: 10/31/2016] [Indexed: 11/16/2022]
Abstract
Rationale:
Phosphodiesterase 2 is a dual substrate esterase, which has the unique property to be stimulated by cGMP, but primarily hydrolyzes cAMP. Myocardial phosphodiesterase 2 is upregulated in human heart failure, but its role in the heart is unknown.
Objective:
To explore the role of phosphodiesterase 2 in cardiac function, propensity to arrhythmia, and myocardial infarction.
Methods and Results:
Pharmacological inhibition of phosphodiesterase 2 (BAY 60–7550, BAY) led to a significant positive chronotropic effect on top of maximal β-adrenoceptor activation in healthy mice. Under pathological conditions induced by chronic catecholamine infusions, BAY reversed both the attenuated β-adrenoceptor–mediated inotropy and chronotropy. Conversely, ECG telemetry in heart-specific phosphodiesterase 2-transgenic (TG) mice showed a marked reduction in resting and in maximal heart rate, whereas cardiac output was completely preserved because of greater cardiac contraction. This well-tolerated phenotype persisted in elderly TG with no indications of cardiac pathology or premature death. During arrhythmia provocation induced by catecholamine injections, TG animals were resistant to triggered ventricular arrhythmias. Accordingly, Ca
2+
-spark analysis in isolated TG cardiomyocytes revealed remarkably reduced Ca
2+
leakage and lower basal phosphorylation levels of Ca
2+
-cycling proteins including ryanodine receptor type 2. Moreover, TG demonstrated improved cardiac function after myocardial infarction.
Conclusions:
Endogenous phosphodiesterase 2 contributes to heart rate regulation. Greater phosphodiesterase 2 abundance protects against arrhythmias and improves contraction force after severe ischemic insult. Activating myocardial phosphodiesterase 2 may, thus, represent a novel intracellular antiadrenergic therapeutic strategy protecting the heart from arrhythmia and contractile dysfunction.
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Affiliation(s)
- Christiane Vettel
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Marta Lindner
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Matthias Dewenter
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Kristina Lorenz
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Constanze Schanbacher
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Merle Riedel
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Simon Lämmle
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Simone Meinecke
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Fleur E. Mason
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Samuel Sossalla
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Andreas Geerts
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Michael Hoffmann
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Frank Wunder
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Fabian J. Brunner
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Thomas Wieland
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Hind Mehel
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Sarah Karam
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Patrick Lechêne
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Jérôme Leroy
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Grégoire Vandecasteele
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Michael Wagner
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Rodolphe Fischmeister
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
| | - Ali El-Armouche
- From the Institute of Experimental and Clinical Pharmacology and Toxicology, University Medical Center Mannheim, Heidelberg University, Germany (C.V., T.W.); Institute of Pharmacology, University Medical Center Göttingen (UMG) Heart Center, Georg August University Medical School Göttingen, Germany (C.V., M.D., M.R., S.M.); UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France (M.L., H.M., S.K., P.L., J.L., G.V., R.F.); Department of Molecular Cardiology and
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Sharpe EJ, St Clair JR, Proenza C. Methods for the Isolation, Culture, and Functional Characterization of Sinoatrial Node Myocytes from Adult Mice. J Vis Exp 2016. [PMID: 27805586 DOI: 10.3791/54555] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Sinoatrial node myocytes (SAMs) act as the natural pacemakers of the heart, initiating each heart beat by generating spontaneous action potentials (APs). These pacemaker APs reflect the coordinated activity of numerous membrane currents and intracellular calcium cycling. However the precise mechanisms that drive spontaneous pacemaker activity in SAMs remain elusive. Acutely isolated SAMs are an essential preparation for experiments to dissect the molecular basis of cardiac pacemaking. However, the indistinct anatomy, complex microdissection, and finicky enzymatic digestion conditions have prevented widespread use of acutely isolated SAMs. In addition, methods were not available until recently to permit longer-term culture of SAMs for protein expression studies. Here we provide a step-by-step protocol and video demonstration for the isolation of SAMs from adult mice. A method is also demonstrated for maintaining adult mouse SAMs in vitro and for expression of exogenous proteins via adenoviral infection. Acutely isolated and cultured SAMs prepared via these methods are suitable for a variety of electrophysiological and imaging studies.
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Affiliation(s)
- Emily J Sharpe
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus
| | - Joshua R St Clair
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus; Department of Bioengineering, University of Colorado Anschutz Medical Campus
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus; Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus;
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35
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Moghtadaei M, Jansen HJ, Mackasey M, Rafferty SA, Bogachev O, Sapp JL, Howlett SE, Rose RA. The impacts of age and frailty on heart rate and sinoatrial node function. J Physiol 2016; 594:7105-7126. [PMID: 27598221 DOI: 10.1113/jp272979] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/24/2016] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Sinoatrial node (SAN) function declines with age; however, not all individuals age at the same rate and health status can vary from fit to frail. Frailty was quantified in young and aged mice using a non-invasive frailty index so that the impacts of age and frailty on heart rate and SAN function could be assessed. SAN function was impaired in aged mice due to alterations in electrical conduction, changes in SAN action potential morphology and fibrosis in the SAN. Changes in SAN function, electrical conduction, action potential morphology and fibrosis were correlated with, and graded by, frailty. This study shows that mice of the same chronological age have quantifiable differences in health status that impact heart rate and SAN function and that these differences in health status can be identified using our frailty index. ABSTRACT Sinoatrial node (SAN) dysfunction increases with age, although not all older adults are affected in the same way. This is because people age at different rates and individuals of the same chronological age vary in health status from very fit to very frail. Our objective was to determine the impacts of age and frailty on heart rate (HR) and SAN function using a new model of frailty in ageing mice. Frailty, which was quantified in young and aged mice using a frailty index (FI), was greater in aged vs. young mice. Intracardiac electrophysiology demonstrated that HR was reduced whereas SAN recovery time (SNRT) was prolonged in aged mice; however, both parameters showed heteroscedasticity suggesting differences in health status among mice of similar chronological age. Consistent with this, HR and corrected SNRT were correlated with, and graded by, FI score. Optical mapping of the SAN demonstrated that conduction velocity (CV) was reduced in aged hearts in association with reductions in diastolic depolarization (DD) slope and action potential (AP) duration. In agreement with in vivo results, SAN CV, DD slope and AP durations all correlated with FI score. Finally, SAN dysfunction in aged mice was associated with increased interstitial fibrosis and alterations in expression of matrix metalloproteinases, which also correlated with frailty. These findings demonstrate that age-related SAN dysfunction occurs in association with electrical and structural remodelling and that frailty is a critical determinant of health status of similarly aged animals that correlates with changes in HR and SAN function.
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Affiliation(s)
- Motahareh Moghtadaei
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hailey J Jansen
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Martin Mackasey
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara A Rafferty
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Oleg Bogachev
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - John L Sapp
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.,Division of Cardiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Susan E Howlett
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A Rose
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.,School of Biomedical Engineering, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Lukyanenko YO, Younes A, Lyashkov AE, Tarasov KV, Riordon DR, Lee J, Sirenko SG, Kobrinsky E, Ziman B, Tarasova YS, Juhaszova M, Sollott SJ, Graham DR, Lakatta EG. Ca(2+)/calmodulin-activated phosphodiesterase 1A is highly expressed in rabbit cardiac sinoatrial nodal cells and regulates pacemaker function. J Mol Cell Cardiol 2016; 98:73-82. [PMID: 27363295 DOI: 10.1016/j.yjmcc.2016.06.064] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 11/29/2022]
Abstract
Constitutive Ca(2+)/calmodulin (CaM)-activation of adenylyl cyclases (ACs) types 1 and 8 in sinoatrial nodal cells (SANC) generates cAMP within lipid-raft-rich microdomains to initiate cAMP-protein kinase A (PKA) signaling, that regulates basal state rhythmic action potential firing of these cells. Mounting evidence in other cell types points to a balance between Ca(2+)-activated counteracting enzymes, ACs and phosphodiesterases (PDEs) within these cells. We hypothesized that the expression and activity of Ca(2+)/CaM-activated PDE Type 1A is higher in SANC than in other cardiac cell types. We found that PDE1A protein expression was 5-fold higher in sinoatrial nodal tissue than in left ventricle, and its mRNA expression was 12-fold greater in the corresponding isolated cells. PDE1 activity (nimodipine-sensitive) accounted for 39% of the total PDE activity in SANC lysates, compared to only 4% in left ventricular cardiomyocytes (LVC). Additionally, total PDE activity in SANC lysates was lowest (10%) in lipid-raft-rich and highest (76%) in lipid-raft-poor fractions (equilibrium sedimentation on a sucrose density gradient). In intact cells PDE1A immunolabeling was not localized to the cell surface membrane (structured illumination microscopy imaging), but located approximately within about 150nm inside of immunolabeling of hyperpolarization-activated cyclic nucleotide-gated potassium channels (HCN4), which reside within lipid-raft-rich microenvironments. In permeabilized SANC, in which surface membrane ion channels are not functional, nimodipine increased spontaneous SR Ca(2+) cycling. PDE1A mRNA silencing in HL-1 cells increased the spontaneous beating rate, reduced the cAMP, and increased cGMP levels in response to IBMX, a broad spectrum PDE inhibitor (detected via fluorescence resonance energy transfer microscopy). We conclude that signaling via cAMP generated by Ca(2+)/CaM-activated AC in SANC lipid raft domains is limited by cAMP degradation by Ca(2+)/CaM-activated PDE1A in non-lipid raft domains. This suggests that local gradients of [Ca(2+)]-CaM or different AC and PDE1A affinity regulate both cAMP production and its degradation, and this balance determines the intensity of Ca(2+)-AC-cAMP-PKA signaling that drives SANC pacemaker function.
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Affiliation(s)
- Yevgeniya O Lukyanenko
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Antoine Younes
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Alexey E Lyashkov
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA; Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, 733 N. Broadway, MRB 835, Baltimore, MD 21205, USA.
| | - Kirill V Tarasov
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Daniel R Riordon
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Joonho Lee
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Syevda G Sirenko
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Evgeny Kobrinsky
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Bruce Ziman
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Yelena S Tarasova
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Magdalena Juhaszova
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - Steven J Sollott
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
| | - David R Graham
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, 733 N. Broadway, MRB 835, Baltimore, MD 21205, USA.
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, 251 Bayview Blvd., Baltimore, MD 21224, USA.
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Grinshpon M, Bondarenko VE. Simulation of the effects of moderate stimulation/inhibition of the β1-adrenergic signaling system and its components in mouse ventricular myocytes. Am J Physiol Cell Physiol 2016; 310:C844-56. [DOI: 10.1152/ajpcell.00002.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/02/2016] [Indexed: 01/08/2023]
Abstract
The β1-adrenergic signaling system is one of the most important protein signaling systems in cardiac cells. It regulates cardiac action potential duration, intracellular Ca2+concentration ([Ca2+]i) transients, and contraction force. In this paper, a comprehensive experimentally based mathematical model of the β1-adrenergic signaling system for mouse ventricular myocytes is explored to simulate the effects of moderate stimulations of β1-adrenergic receptors (β1-ARs) on the action potential, Ca2+and Na+dynamics, as well as the effects of inhibition of protein kinase A (PKA) and phosphodiesterase of type 4 (PDE4). Simulation results show that the action potential prolongations reach saturating values at relatively small concentrations of isoproterenol (∼0.01 μM), while the [Ca2+]itransient amplitude saturates at significantly larger concentrations (∼0.1–1.0 μM). The differences in the response of Ca2+and Na+fluxes to moderate stimulation of β1-ARs are also observed. Sensitivity analysis of the mathematical model is performed and the model limitations are discussed. The investigated model reproduces most of the experimentally observed effects of moderate stimulation of β1-ARs, PKA, and PDE4 inhibition on the L-type Ca2+current, [Ca2+]itransients, and the sarcoplasmic reticulum Ca2+load and makes testable predictions for the action potential duration and [Ca2+]itransients as functions of isoproterenol concentration.
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Affiliation(s)
- Mark Grinshpon
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia; and
| | - Vladimir E. Bondarenko
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia; and
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
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38
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Torrente AG, Mesirca P, Neco P, Rizzetto R, Dubel S, Barrere C, Sinegger-Brauns M, Striessnig J, Richard S, Nargeot J, Gomez AM, Mangoni ME. L-type Cav1.3 channels regulate ryanodine receptor-dependent Ca2+ release during sino-atrial node pacemaker activity. Cardiovasc Res 2016; 109:451-61. [PMID: 26786159 DOI: 10.1093/cvr/cvw006] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 01/07/2016] [Indexed: 11/13/2022] Open
Abstract
AIMS Sino-atrial node (SAN) automaticity is an essential mechanism of heart rate generation that is still not completely understood. Recent studies highlighted the importance of intracellular Ca(2+) ([Ca(2+)]i) dynamics during SAN pacemaker activity. Nevertheless, the functional role of voltage-dependent L-type Ca(2+) channels in controlling SAN [Ca(2+)]i release is largely unexplored. Since Cav1.3 is the predominant L-type Ca(2+) channel isoform in SAN cells, we studied [Ca(2+)]i dynamics in isolated cells and ex vivo SAN preparations explanted from wild-type (WT) and Cav1.3 knockout (KO) mice (Cav1.3(-/-)). METHODS AND RESULTS We found that Cav1.3 deficiency strongly impaired [Ca(2+)]i dynamics, reducing the frequency of local [Ca(2+)]i release events and preventing their synchronization. This impairment inhibited the generation of Ca(2+) transients and delayed spontaneous activity. We also used action potentials recorded in WT SAN cells as voltage-clamp commands for Cav1.3(-/-) cells. Although these experiments showed abolished Ca(2+) entry through L-type Ca(2+) channels in the diastolic depolarization range of KO SAN cells, their sarcoplasmic reticulum Ca(2+) load remained normal. β-Adrenergic stimulation enhanced pacemaking of both genotypes, though, Cav1.3(-/-) SAN cells remained slower than WT. Conversely, we rescued pacemaker activity in Cav1.3(-/-) SAN cells and intact tissues through caffeine-mediated stimulation of Ca(2+)-induced Ca(2+) release. CONCLUSIONS Cav1.3 channels play a critical role in the regulation of [Ca(2+)]i dynamics, providing an unanticipated mechanism for triggering local [Ca(2+)]i releases and thereby controlling pacemaker activity. Our study also provides an additional pathophysiological mechanism for congenital SAN dysfunction and heart block linked to Cav1.3 loss of function in humans.
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Affiliation(s)
- Angelo Giovanni Torrente
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Pietro Mesirca
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Patricia Neco
- UMR-S 1180, Inserm, Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France Department of Pharmacology and Toxicology, Institute of Pharmacy
| | - Riccardo Rizzetto
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Stefan Dubel
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Christian Barrere
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Martina Sinegger-Brauns
- Department of Pharmacology and Toxicology, Institute of Pharmacy Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Joerg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria
| | - Sylvain Richard
- INSERM, U1046, Montpellier, France CNRS UMR 9214, PhyMedExp, University of Montpellier, France
| | - Joël Nargeot
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
| | - Ana Maria Gomez
- UMR-S 1180, Inserm, Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France Department of Pharmacology and Toxicology, Institute of Pharmacy
| | - Matteo Elia Mangoni
- Département de Physiologie, CNRS, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34000, France INSERM, U1191, Montpellier F-34000, France Université de Montpellier, UMR-5203, Montpellier F-34000, France
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Moghtadaei M, Polina I, Rose RA. Electrophysiological effects of natriuretic peptides in the heart are mediated by multiple receptor subtypes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 120:37-49. [DOI: 10.1016/j.pbiomolbio.2015.12.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/25/2015] [Accepted: 12/02/2015] [Indexed: 12/13/2022]
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Galindo-Tovar A, Vargas ML, Kaumann AJ. Inhibitors of phosphodiesterases PDE2, PDE3, and PDE4 do not increase the sinoatrial tachycardia of noradrenaline and prostaglandin PGE₁ in mice. Naunyn Schmiedebergs Arch Pharmacol 2015; 389:177-86. [PMID: 26531832 DOI: 10.1007/s00210-015-1178-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/29/2015] [Indexed: 12/30/2022]
Abstract
Phosphodiesterases PDE2, PDE3, and PDE4 are expressed in murine sinoatrial cells. PDE3 and/or PDE4 reduce heart rate but apparently do not influence the tachycardia mediated through sinoatrial β1- and β2-adrenoceptors despite the high content of sinoatrial cAMP. The function of PDE2 is, however, uncertain. Prostaglandin PGE1 elicits sinoatrial tachycardia through EP receptors, but the control by phosphodiesterases is unknown. We investigated on spontaneously beating right atria of mice the effects of the PDE2 inhibitors Bay 60-7550 and EHNA on basal beating and the tachycardia produced by noradrenaline (3 nM) and PGE1 (1 μM). Bay 60-7550 (1 μM), but not EHNA (10 μM), increased basal sinoatrial beating. EHNA also failed to produce tachycardia in the presence of the adenosine deaminase inhibitor 2'-deoxycoformycin (10 μM), remaining inconclusive whether PDE2 reduces basal sinoatrial beating. Rolipram (10 μM) and cilostamide (300 nM) caused moderate tachycardia. The tachycardia evoked by Bay 60-7550 was similar in the absence and presence of rolipram. Noradrenaline elicited stable tachycardia that was not increased by Bay 60-7550. A stable tachycardia caused by PGE1 was not increased by the inhibitors of PDE2, PDE3, and PDE4. Unlike PDE3 and PDE4 which reduce murine basal sinoatrial beating, a possible effect of PDE2 needs further research. The stable tachycardia produced by noradrenaline and PGE1, together with the lack potentiation by the inhibitors of PDE2, PDE3, and PDE4, suggests that cAMP generated at the receptor compartments is hardly hydrolyzed by these phophodiesterases. Evidence from human volunteers is consistent with this proposal.
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Affiliation(s)
- Alejandro Galindo-Tovar
- Departamento de Tecnología de la Alimentación y Nutrición, Facultad Ciencia de la Salud, Universidad Católica de Murcia, Murcia, 30107, Spain
| | - María Luisa Vargas
- Departamento de Farmacología, Facultad de Medicina, Universidad de Murcia, Campus de Espinardo, Murcia, 30100, Spain
| | - Alberto J Kaumann
- Departamento de Farmacología, Facultad de Medicina, Universidad de Murcia, Campus de Espinardo, Murcia, 30100, Spain.
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Sustained exposure to catecholamines affects cAMP/PKA compartmentalised signalling in adult rat ventricular myocytes. Cell Signal 2015; 28:725-32. [PMID: 26475678 PMCID: PMC4872538 DOI: 10.1016/j.cellsig.2015.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 10/12/2015] [Indexed: 01/08/2023]
Abstract
In the heart compartmentalisation of cAMP/protein kinase A (PKA) signalling is necessary to achieve a specific functional outcome in response to different hormonal stimuli. Chronic exposure to catecholamines is known to be detrimental to the heart and disrupted compartmentalisation of cAMP signalling has been associated to heart disease. However, in most cases it remains unclear whether altered local cAMP signalling is an adaptive response, a consequence of the disease or whether it contributes to the pathogenetic process. We have previously demonstrated that isoforms of PKA expressed in cardiac myocytes, PKA-I and PKA-II, localise to different subcellular compartments and are selectively activated by spatially confined pools of cAMP, resulting in phosphorylation of distinct downstream targets. Here we investigate cAMP signalling in an in vitro model of hypertrophy in primary adult rat ventricular myocytes. By using a real time imaging approach and targeted reporters we find that that sustained exposure to catecholamines can directly affect cAMP/PKA compartmentalisation. This appears to involve a complex mechanism including both changes in the subcellular localisation of individual phosphodiesterase (PDE) isoforms as well as the relocalisation of PKA isoforms. As a result, the preferential coupling of PKA subsets with different PDEs is altered resulting in a significant difference in the level of cAMP the kinase is exposed to, with potential impact on phosphorylation of downstream targets.
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Hua R, MacLeod SL, Polina I, Moghtadaei M, Jansen HJ, Bogachev O, O’Blenes SB, Sapp JL, Legare JF, Rose RA. Effects of Wild-Type and Mutant Forms of Atrial Natriuretic Peptide on Atrial Electrophysiology and Arrhythmogenesis. Circ Arrhythm Electrophysiol 2015; 8:1240-54. [DOI: 10.1161/circep.115.002896] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 07/10/2015] [Indexed: 11/16/2022]
Abstract
Background—
Atrial natriuretic peptide (ANP) is a hormone with numerous beneficial cardiovascular effects. Recently, a mutation in the ANP gene, which results in the generation of a mutant form of ANP (mANP), was identified and shown to cause atrial fibrillation in people. The mechanism(s) through which mANP causes atrial fibrillation is unknown. Our objective was to compare the effects of wild-type ANP and mANP on atrial electrophysiology in mice and humans.
Methods and Results—
Action potentials (APs), L-type Ca
2+
currents (
I
Ca,L
), and Na
+
current were recorded in atrial myocytes from wild-type or natriuretic peptide receptor C knockout (NPR-C
−/−
) mice. In mice, ANP and mANP (10–100 nmol/L) had opposing effects on atrial myocyte AP morphology and
I
Ca,L
. ANP increased AP upstroke velocity (
V
max
), AP duration, and
I
Ca,L
similarly in wild-type and NPR-C
−/−
myocytes. In contrast, mANP decreased
V
max
, AP duration, and
I
Ca,L
, and these effects were completely absent in NPR-C
−/−
myocytes. ANP and mANP also had opposing effects on
I
Ca,L
in human atrial myocytes. In contrast, neither ANP nor mANP had any effect on Na
+
current in mouse atrial myocytes. Optical mapping studies in mice demonstrate that ANP sped electric conduction in the atria, whereas mANP did the opposite and slowed atrial conduction. Atrial pacing in the presence of mANP induced arrhythmias in 62.5% of hearts, whereas treatment with ANP completely prevented the occurrence of arrhythmias.
Conclusions—
These findings provide mechanistic insight into how mANP causes atrial fibrillation and demonstrate that wild-type ANP is antiarrhythmic.
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Affiliation(s)
- Rui Hua
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sarah L. MacLeod
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Iuliia Polina
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Motahareh Moghtadaei
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hailey J. Jansen
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Oleg Bogachev
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Stacy B. O’Blenes
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - John L. Sapp
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jean-Francois Legare
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A. Rose
- From the Department of Physiology and Biophysics (R.H., S.L.M., I.P., M.M., H.J.J., O.B., S.B.O., J.L.S., R.A.R.), IWK Health Centre (S.B.O.), Department of Surgery (S.B.O., J.-F.L.), Division of Cardiology (J.L.S.), School of Biomedical Engineering (R.A.R.), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Soler F, Fernández-Belda F, Pérez-Schindler J, Hernández-Cascales J. Single inhibition of either PDE3 or PDE4 unmasks β2-adrenoceptor-mediated inotropic and lusitropic effects in the left but not right ventricular myocardium of rat. Eur J Pharmacol 2015; 765:429-36. [DOI: 10.1016/j.ejphar.2015.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/18/2015] [Accepted: 09/01/2015] [Indexed: 02/05/2023]
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Zoccarato A, Surdo NC, Aronsen JM, Fields LA, Mancuso L, Dodoni G, Stangherlin A, Livie C, Jiang H, Sin YY, Gesellchen F, Terrin A, Baillie GS, Nicklin SA, Graham D, Szabo-Fresnais N, Krall J, Vandeput F, Movsesian M, Furlan L, Corsetti V, Hamilton G, Lefkimmiatis K, Sjaastad I, Zaccolo M. Cardiac Hypertrophy Is Inhibited by a Local Pool of cAMP Regulated by Phosphodiesterase 2. Circ Res 2015; 117:707-19. [PMID: 26243800 DOI: 10.1161/circresaha.114.305892] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 08/04/2015] [Indexed: 12/25/2022]
Abstract
RATIONALE Chronic elevation of 3'-5'-cyclic adenosine monophosphate (cAMP) levels has been associated with cardiac remodeling and cardiac hypertrophy. However, enhancement of particular aspects of cAMP/protein kinase A signaling seems to be beneficial for the failing heart. cAMP is a pleiotropic second messenger with the ability to generate multiple functional outcomes in response to different extracellular stimuli with strict fidelity, a feature that relies on the spatial segregation of the cAMP pathway components in signaling microdomains. OBJECTIVE How individual cAMP microdomains affect cardiac pathophysiology remains largely to be established. The cAMP-degrading enzymes phosphodiesterases (PDEs) play a key role in shaping local changes in cAMP. Here we investigated the effect of specific inhibition of selected PDEs on cardiac myocyte hypertrophic growth. METHODS AND RESULTS Using pharmacological and genetic manipulation of PDE activity, we found that the rise in cAMP resulting from inhibition of PDE3 and PDE4 induces hypertrophy, whereas increasing cAMP levels via PDE2 inhibition is antihypertrophic. By real-time imaging of cAMP levels in intact myocytes and selective displacement of protein kinase A isoforms, we demonstrate that the antihypertrophic effect of PDE2 inhibition involves the generation of a local pool of cAMP and activation of a protein kinase A type II subset, leading to phosphorylation of the nuclear factor of activated T cells. CONCLUSIONS Different cAMP pools have opposing effects on cardiac myocyte cell size. PDE2 emerges as a novel key regulator of cardiac hypertrophy in vitro and in vivo, and its inhibition may have therapeutic applications.
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Affiliation(s)
- Anna Zoccarato
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Nicoletta C Surdo
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Jan M Aronsen
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Laura A Fields
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Luisa Mancuso
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Giuliano Dodoni
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Alessandra Stangherlin
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Craig Livie
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - He Jiang
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Yuan Yan Sin
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Frank Gesellchen
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Anna Terrin
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - George S Baillie
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Stuart A Nicklin
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Delyth Graham
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Nicolas Szabo-Fresnais
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Judith Krall
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Fabrice Vandeput
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Matthew Movsesian
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Leonardo Furlan
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Veronica Corsetti
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Graham Hamilton
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Konstantinos Lefkimmiatis
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Ivar Sjaastad
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.)
| | - Manuela Zaccolo
- From the Institute of Neuroscience and Psychology (A.Z., L.A.F., A.S., C.L., H.J., F.G., A.T., G.H., M.Z.) and Institute of Cardiovascular and Medical Sciences (Y.Y.S., G.S.B., S.A.N., D.G.), University of Glasgow, Glasgow, UK; Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK (N.C.S., K.L., M.Z.); Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway (J.M.A., I.S.); Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy (L.M., G.D., A.T., L.F., V.C.); Cardiology Section, VA Salt Lake City Health Care System and Cardiovascular Medicine Division, University of Utah School of Medicine, Salt Lake City, UT (N.S.-F., J.K., F.V., M.M.); Bjorknes College, Oslo, Norway (J.M.A.); and BHF Centre of Research Excellence, Oxford, UK (K.L., M.Z.).
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Spatiotemporal stability of neonatal rat cardiomyocyte monolayers spontaneous activity is dependent on the culture substrate. PLoS One 2015; 10:e0127977. [PMID: 26035822 PMCID: PMC4452796 DOI: 10.1371/journal.pone.0127977] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 04/21/2015] [Indexed: 11/27/2022] Open
Abstract
In native conditions, cardiac cells must continuously comply with diverse stimuli necessitating a perpetual adaptation. Polydimethylsiloxane (PDMS) is commonly used in cell culture to study cellular response to changes in the mechanical environment. The aim of this study was to evaluate the impact of using PDMS substrates on the properties of spontaneous activity of cardiomyocyte monolayer cultures. We compared PDMS to the gold standard normally used in culture: a glass substrate. Although mean frequency of spontaneous activity remained unaltered, incidence of reentrant activity was significantly higher in samples cultured on glass compared to PDMS substrates. Higher spatial and temporal instability of the spontaneous rate activation was found when cardiomyocytes were cultured on PDMS, and correlated with decreased connexin-43 and increased CaV3.1 and HCN2 mRNA levels. Compared to cultures on glass, cultures on PDMS were associated with the strongest response to isoproterenol and acetylcholine. These results reveal the importance of carefully selecting the culture substrate for studies involving mechanical stimulation, especially for tissue engineering or pharmacological high-throughput screening of cardiac tissue analog.
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Krishnaswamy PS, Egom EE, Moghtadaei M, Jansen HJ, Azer J, Bogachev O, Mackasey M, Robbins C, Rose RA. Altered parasympathetic nervous system regulation of the sinoatrial node in Akita diabetic mice. J Mol Cell Cardiol 2015; 82:125-35. [DOI: 10.1016/j.yjmcc.2015.02.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 02/21/2015] [Accepted: 02/26/2015] [Indexed: 11/26/2022]
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Capel RA, Terrar DA. The importance of Ca(2+)-dependent mechanisms for the initiation of the heartbeat. Front Physiol 2015; 6:80. [PMID: 25859219 PMCID: PMC4373508 DOI: 10.3389/fphys.2015.00080] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/02/2015] [Indexed: 01/01/2023] Open
Abstract
Mechanisms underlying pacemaker activity in the sinus node remain controversial, with some ascribing a dominant role to timing events in the surface membrane (“membrane clock”) and others to uptake and release of calcium from the sarcoplasmic reticulum (SR) (“calcium clock”). Here we discuss recent evidence on mechanisms underlying pacemaker activity with a particular emphasis on the many roles of calcium. There are particular areas of controversy concerning the contribution of calcium spark-like events and the importance of I(f) to spontaneous diastolic depolarisation, though it will be suggested that neither of these is essential for pacemaking. Sodium-calcium exchange (NCX) is most often considered in the context of mediating membrane depolarisation after spark-like events. We present evidence for a broader role of this electrogenic exchanger which need not always depend upon these spark-like events. Short (milliseconds or seconds) and long (minutes) term influences of calcium are discussed including direct regulation of ion channels and NCX, and control of the activity of calcium-dependent enzymes (including CaMKII, AC1, and AC8). The balance between the many contributory factors to pacemaker activity may well alter with experimental and clinical conditions, and potentially redundant mechanisms are desirable to ensure the regular spontaneous heart rate that is essential for life. This review presents evidence that calcium is central to the normal control of pacemaking across a range of temporal scales and seeks to broaden the accepted description of the “calcium clock” to cover these important influences.
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Affiliation(s)
- Rebecca A Capel
- British Heart Foundation Centre of Research Excellence, Department of Pharmacology, University of Oxford Oxford, UK
| | - Derek A Terrar
- British Heart Foundation Centre of Research Excellence, Department of Pharmacology, University of Oxford Oxford, UK
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Carbon monoxide modulates electrical activity of murine myocardium via cGMP-dependent mechanisms. J Physiol Biochem 2015; 71:107-19. [PMID: 25670496 DOI: 10.1007/s13105-015-0387-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/25/2015] [Indexed: 10/24/2022]
Abstract
Carbon monoxide (CO) is critical in cell signaling, and inhalation of gaseous CO can impact cardiovascular physiology. We have investigated electrophysiological effects of CO and their potential cGMP-dependent mechanism in isolated preparations of murine myocardium. The standard microelectrode technique was used to record myocardial action potentials (APs). Exogenous CO (0.96 × 10(-4)-4.8 × 10(-4) M) decreased AP duration in atrial and ventricular tissue and accelerated pacemaking activity in sinoatrial node. Inhibitors of heme oxygenases (zinc and tin protoporphyrin IX), which are responsible for endogenous CO production, induced the opposite effects. Inhibitor of soluble guanylate cyclase (sGC), ODQ (10(-5) M) halved CO-induced AP shortening, while sGC activator azosidnone (10(-5) M-3 × 10(-4) M) and cGMP analog BrcGMP (3 × 10(-4) M) induced the same effects as CO. To see if CO effects are attributed to differential regulation of phosphodiesterase 2 (PDE2) and 3 (PDE3), we used inhibitors of these enzymes. Milrinone (2 × 10(-6) M), selective inhibitor of cGMP-downregulated PDE3, blocked CO-induced rhythm acceleration. EHNA(2 × 10(-6) M), which inhibits cGMP-upregulated PDE2, attenuated CO-induced AP shortening, but failed to induce any positive chronotropic effect. Our findings indicate that PDE2 activity prevails in working myocardium, while PDE3 is more active in sinoatrial node. The results suggest that cardiac effects of CO are at least partly attributed to activation of sGC and subsequent elevation of cGMP intracellular content. In sinoatrial node, this leads to PDE3 inhibition, increased cAMP content, and positive chronotropy, while it also causes PDE2 stimulation in working myocardium, thereby enhancing cAMP degradation and producing AP shortening. Thus, CO induces significant alterations of cardiac electrical activity via cGMP-dependent mechanism and should be considered as a novel regulator of cardiac electrophysiology.
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49
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Egom EE, Vella K, Hua R, Jansen HJ, Moghtadaei M, Polina I, Bogachev O, Hurnik R, Mackasey M, Rafferty S, Ray G, Rose RA. Impaired sinoatrial node function and increased susceptibility to atrial fibrillation in mice lacking natriuretic peptide receptor C. J Physiol 2015; 593:1127-46. [PMID: 25641115 DOI: 10.1113/jphysiol.2014.283135] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 12/06/2014] [Indexed: 12/17/2022] Open
Abstract
Natriuretic peptides (NPs) are critical regulators of the cardiovascular system that are currently viewed as possible therapeutic targets for the treatment of heart disease. Recent work demonstrates potent NP effects on cardiac electrophysiology, including in the sinoatrial node (SAN) and atria. NPs elicit their effects via three NP receptors (NPR-A, NPR-B and NPR-C). Among these receptors, NPR-C is poorly understood. Accordingly, the goal of this study was to determine the effects of NPR-C ablation on cardiac structure and arrhythmogenesis. Cardiac structure and function were assessed in wild-type (NPR-C(+/+)) and NPR-C knockout (NPR-C(-/-)) mice using echocardiography, intracardiac programmed stimulation, patch clamping, high-resolution optical mapping, quantitative polymerase chain reaction and histology. These studies demonstrate that NPR-C(-/-) mice display SAN dysfunction, as indicated by a prolongation (30%) of corrected SAN recovery time, as well as an increased susceptibility to atrial fibrillation (6% in NPR-C(+/+) vs. 47% in NPR-C(-/-)). There were no differences in SAN or atrial action potential morphology in NPR-C(-/-) mice; however, increased atrial arrhythmogenesis in NPR-C(-/-) mice was associated with reductions in SAN (20%) and atrial (15%) conduction velocity, as well as increases in expression and deposition of collagen in the atrial myocardium. No differences were seen in ventricular arrhythmogenesis or fibrosis in NPR-C(-/-) mice. This study demonstrates that loss of NPR-C results in SAN dysfunction and increased susceptibility to atrial arrhythmias in association with structural remodelling and fibrosis in the atrial myocardium. These findings indicate a critical protective role for NPR-C in the heart.
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Affiliation(s)
- Emmanuel E Egom
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Soler F, Fernández-Belda F, Pérez-Schindler J, Handschin C, Fuente T, Hernandez-Cascales J. PDE2 activity differs in right and left rat ventricular myocardium and differentially regulates β2 adrenoceptor-mediated effects. Exp Biol Med (Maywood) 2014; 240:1205-13. [PMID: 25432985 DOI: 10.1177/1535370214560969] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/30/2014] [Indexed: 11/16/2022] Open
Abstract
The important regulator of cardiac function, cAMP, is hydrolyzed by different cyclic nucleotide phosphodiesterases (PDEs), whose expression and activity are not uniform throughout the heart. Of these enzymes, PDE2 shapes β1 adrenoceptor-dependent cardiac cAMP signaling, both in the right and left ventricular myocardium, but its role in regulating β2 adrenoceptor-mediated responses is less well known. Our aim was to investigate possible differences in PDE2 transcription and activity between right (RV) and left (LV) rat ventricular myocardium, as well as its role in regulating β2 adrenoceptor effects. The free walls of the RV and the LV were obtained from Sprague-Dawley rat hearts. Relative mRNA for PDE2 (quantified by qPCR) and PDE2 activity (evaluated by a colorimetric procedure and using the PDE2 inhibitor EHNA) were determined in RV and LV. Also, β2 adrenoceptor-mediated effects (β2-adrenoceptor agonist salbutamol + β1 adrenoceptor antagonist CGP-20712A) on contractility and cAMP concentrations, in the absence or presence of EHNA, were studied in the RV and LV. PDE2 transcript levels were less abundant in RV than in LV and the contribution of PDE2 to the total PDE activity was around 25% lower in the microsomal fraction of the RV compared with the LV. β2 adrenoceptor activation increased inotropy and cAMP levels in the LV when measured in the presence of EHNA, but no such effects were observed in the RV, either in the presence or absence of EHNA. These results indicate interventricular differences in PDE2 transcript and activity levels, which may distinctly regulate β2 adrenoceptor-mediated contractility and cAMP concentrations in the RV and in the LV of the rat heart.
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Affiliation(s)
- Fernando Soler
- Department of Biochemistry and Molecular Biology A, University of Murcia, 30100 Murcia, Spain
| | | | | | - Christoph Handschin
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Teodomiro Fuente
- Unit of Radiopharmacy, University Hospital Virgen de la Arrixaca, 30120 Murcia, Spain
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