1
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Kampourakis T, Ponnam S, Campbell KS, Wellette-Hunsucker A, Koch D. Cardiac myosin binding protein-C phosphorylation as a function of multiple protein kinase and phosphatase activities. Nat Commun 2024; 15:5111. [PMID: 38877002 PMCID: PMC11178824 DOI: 10.1038/s41467-024-49408-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/05/2024] [Indexed: 06/16/2024] Open
Abstract
Phosphorylation of cardiac myosin binding protein-C (cMyBP-C) is a determinant of cardiac myofilament function. Although cMyBP-C phosphorylation by various protein kinases has been extensively studied, the influence of protein phosphatases on cMyBP-C's multiple phosphorylation sites has remained largely obscure. Here we provide a detailed biochemical characterization of cMyBP-C dephosphorylation by protein phosphatases 1 and 2 A (PP1 and PP2A), and develop an integrated kinetic model for cMyBP-C phosphorylation using data for both PP1, PP2A and various protein kinases known to phosphorylate cMyBP-C. We find strong site-specificity and a hierarchical mechanism for both phosphatases, proceeding in the opposite direction of sequential phosphorylation by potein kinase A. The model is consistent with published data from human patients and predicts complex non-linear cMyBP-C phosphorylation patterns that are validated experimentally. Our results suggest non-redundant roles for PP1 and PP2A under both physiological and heart failure conditions, and emphasize the importance of phosphatases for cMyBP-C regulation.
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Affiliation(s)
- Thomas Kampourakis
- Randall Centre for Cell and Molecular Biophysics; and British Heart Foundation Centre of Research Excellence, King's College London, London, SE1 1UL, United Kingdom
| | - Saraswathi Ponnam
- Randall Centre for Cell and Molecular Biophysics; and British Heart Foundation Centre of Research Excellence, King's College London, London, SE1 1UL, United Kingdom
| | - Kenneth S Campbell
- Division of Cardiovascular Medicine, University of Kentucky, Lexington, KY, USA
| | | | - Daniel Koch
- Max Planck Institute for Neurobiology of Behavior-caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
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2
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Perez DM. α 1-Adrenergic Receptors: Insights into Potential Therapeutic Opportunities for COVID-19, Heart Failure, and Alzheimer's Disease. Int J Mol Sci 2023; 24:4188. [PMID: 36835598 PMCID: PMC9963459 DOI: 10.3390/ijms24044188] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/22/2023] Open
Abstract
α1-Adrenergic receptors (ARs) are members of the G-Protein Coupled Receptor superfamily and with other related receptors (β and α2), they are involved in regulating the sympathetic nervous system through binding and activation by norepinephrine and epinephrine. Traditionally, α1-AR antagonists were first used as anti-hypertensives, as α1-AR activation increases vasoconstriction, but they are not a first-line use at present. The current usage of α1-AR antagonists increases urinary flow in benign prostatic hyperplasia. α1-AR agonists are used in septic shock, but the increased blood pressure response limits use for other conditions. However, with the advent of genetic-based animal models of the subtypes, drug design of highly selective ligands, scientists have discovered potentially newer uses for both agonists and antagonists of the α1-AR. In this review, we highlight newer treatment potential for α1A-AR agonists (heart failure, ischemia, and Alzheimer's disease) and non-selective α1-AR antagonists (COVID-19/SARS, Parkinson's disease, and posttraumatic stress disorder). While the studies reviewed here are still preclinical in cell lines and rodent disease models or have undergone initial clinical trials, potential therapeutics discussed here should not be used for non-approved conditions.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
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3
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Mechanisms for the α-Adrenoceptor-Mediated Positive Inotropy in Mouse Ventricular Myocardium: Enhancing Effect of Action Potential Prolongation. Int J Mol Sci 2023; 24:ijms24043926. [PMID: 36835338 PMCID: PMC9964142 DOI: 10.3390/ijms24043926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
Mechanisms for the α-adrenoceptor-mediated positive inotropy in neonatal mouse ventricular myocardium were studied with isolated myocardial preparations. The phenylephrine-induced positive inotropy was suppressed by prazosin, nifedipine, and chelerythrine, a protein kinase C inhibitor, but not by SEA0400, a selective Na+/Ca2+ exchanger inhibitor. Phenylephrine increased the L-type Ca2+ channel current and prolonged the action potential duration, while the voltage-dependent K+ channel current was not influenced. In the presence of cromakalim, an ATP-sensitive K+ channel opener, the phenylephrine-induced prolongation of action potential duration, as well as the positive inotropy, were smaller than in the absence of cromakalim. These results suggest that the α-adrenoceptor-mediated positive inotropy is mediated by an increase in Ca2+ influx through the L-type Ca2+ channel, and the concomitant increase in action potential duration acts as an enhancing factor.
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Chronic isoprenaline/phenylephrine vs. exclusive isoprenaline stimulation in mice: critical contribution of alpha 1-adrenoceptors to early cardiac stress responses. Basic Res Cardiol 2022; 117:15. [PMID: 35286475 PMCID: PMC8921177 DOI: 10.1007/s00395-022-00920-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 02/04/2022] [Accepted: 02/07/2022] [Indexed: 01/31/2023]
Abstract
Hyperactivity of the sympathetic nervous system is a major driver of cardiac remodeling, exerting its effects through both α-, and β-adrenoceptors (α-, β-ARs). As the relative contribution of subtype α1-AR to cardiac stress responses remains poorly investigated, we subjected mice to either subcutaneous perfusion with the β-AR agonist isoprenaline (ISO, 30 mg/kg × day) or to a combination of ISO and the stable α1-AR agonist phenylephrine (ISO/PE, 30 mg/kg × day each). Telemetry analysis revealed similar hemodynamic responses under both ISO and ISO/PE treatment i.e., permanently increased heart rates and only transient decreases in mean blood pressure during the first 24 h. Echocardiography and single cell analysis after 1 week of exposure showed that ISO/PE-, but not ISO-treated animals established α1-AR-mediated inotropic responsiveness to acute adrenergic stimulation. Morphologically, additional PE perfusion limited concentric cardiomyocyte growth and enhanced cardiac collagen deposition during 7 days of treatment. Time-course analysis demonstrated a diverging development in transcriptional patterns at day 4 of treatment i.e., increased expression of selected marker genes Xirp2, Nppa, Tgfb1, Col1a1, Postn under chronic ISO/PE treatment which was either less pronounced or absent in the ISO group. Transcriptome analyses at day 4 via RNA sequencing demonstrated that additional PE treatment caused a marked upregulation of genes allocated to extracellular matrix and fiber organization along with a more pronounced downregulation of genes involved in metabolic processes, muscle adaptation and cardiac electrophysiology. Consistently, transcriptome changes under ISO/PE challenge more effectively recapitulated early transcriptional alterations in pressure overload-induced experimental heart failure and in human hypertrophic cardiomyopathy.
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5
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Averin AS, Andreeva LA, Popova SS, Kosarsky LS, Anufriev AI, Nenov MN, Nakipova OV. α1-Adrenergic receptor regulates papillary muscle and aortic segment contractile function via modulation of store-operated Ca 2+ entry in long-tailed ground squirrels Urocitellus undulatus. J Comp Physiol B 2021; 191:10.1007/s00360-021-01394-6. [PMID: 34297192 DOI: 10.1007/s00360-021-01394-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 06/28/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
The effect of phenylephrine (PE) on right ventricle papillary muscle (PM) and aortic segment (AS) contractile activity was studied in long-tailed ground squirrels Urocitellus undulatus during summer activity, torpor and interbout active (IBA) periods in comparison to rat. We found that PE (10 μM) exerts positive inotropic effect on ground squirrel PM that was blocked by α1-AR inhibitor-prazosin. PE differently affected frequency dependence of PM contraction in ground squirrels and rats. PE significantly increased the force of PM contraction in summer and hibernating ground squirrels including both torpor and IBA predominantly at the range of low stimulation frequencies (0.003-0.1 Hz), while in rat PM it was evident only at high stimulation frequency range (0.2-1.0 Hz). Further, it was found that PE vasoconstrictor effect on AS contractility is significantly higher in ground squirrels of torpid state compared to IBA and summer periods. Overall vasoconstrictor effect of PE was significantly higher in AS of ground squirrels of all periods compared to rats. Positive inotropic effect of PE on PM along with its vasoconstrictor effect on AS of ground squirrels was not affected by pretreatment with inhibitors of L-type Ca2+ channels, or Na+/Ca2+ exchanger or Ca2+-ATPase but was completely blocked by an inhibitor of store-operated Ca2+ entry (SOCE)-2-APB, suggesting the involvement of SOCE in the mechanisms underlying PE action on ground squirrel cardiovascular system. Obtained results support an idea about the significant role of alpha1-AR in adaptive mechanisms critical for the maintaining of cardiovascular contractile function in long-tailed ground squirrel Urocitellus undulatus.
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Affiliation(s)
- Alexey S Averin
- Institute of Cell Biophysics Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya 3, Pushchino, Moscow region, Russia, 142290
| | - Ludmila A Andreeva
- Institute of Cell Biophysics Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya 3, Pushchino, Moscow region, Russia, 142290
| | - Svetlana S Popova
- Institute of Theoretical and Experimental Biophysics of Russian Academy of Science, Institutskaya 3, Pushchino, Moscow region, Russia, 142290
| | - Leonid S Kosarsky
- Institute of Cell Biophysics Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya 3, Pushchino, Moscow region, Russia, 142290
| | - Andrey I Anufriev
- Yakutsk Branch, Siberian Division, Institute of Biology, Russian Academy of Sciences, Yakutsk, Russia, 677891
| | - Miroslav N Nenov
- Institute of Theoretical and Experimental Biophysics of Russian Academy of Science, Institutskaya 3, Pushchino, Moscow region, Russia, 142290.
- Alzheimer's Center at Temple, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
| | - Olga V Nakipova
- Institute of Cell Biophysics Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institutskaya 3, Pushchino, Moscow region, Russia, 142290
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6
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Perez DM. Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure. Int J Mol Sci 2021; 22:5783. [PMID: 34071350 PMCID: PMC8198887 DOI: 10.3390/ijms22115783] [Citation(s) in RCA: 9] [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: 05/10/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
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7
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Perez DM. Current Developments on the Role of α 1-Adrenergic Receptors in Cognition, Cardioprotection, and Metabolism. Front Cell Dev Biol 2021; 9:652152. [PMID: 34113612 PMCID: PMC8185284 DOI: 10.3389/fcell.2021.652152] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
The α1-adrenergic receptors (ARs) are G-protein coupled receptors that bind the endogenous catecholamines, norepinephrine, and epinephrine. They play a key role in the regulation of the sympathetic nervous system along with β and α2-AR family members. While all of the adrenergic receptors bind with similar affinity to the catecholamines, they can regulate different physiologies and pathophysiologies in the body because they couple to different G-proteins and signal transduction pathways, commonly in opposition to one another. While α1-AR subtypes (α1A, α1B, α1C) have long been known to be primary regulators of vascular smooth muscle contraction, blood pressure, and cardiac hypertrophy, their role in neurotransmission, improving cognition, protecting the heart during ischemia and failure, and regulating whole body and organ metabolism are not well known and are more recent developments. These advancements have been made possible through the development of transgenic and knockout mouse models and more selective ligands to advance their research. Here, we will review the recent literature to provide new insights into these physiological functions and possible use as a therapeutic target.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
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8
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Zhang J, Simpson PC, Jensen BC. Cardiac α1A-adrenergic receptors: emerging protective roles in cardiovascular diseases. Am J Physiol Heart Circ Physiol 2020; 320:H725-H733. [PMID: 33275531 DOI: 10.1152/ajpheart.00621.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
α1-Adrenergic receptors (ARs) are catecholamine-activated G protein-coupled receptors (GPCRs) that are expressed in mouse and human myocardium and vasculature, and play essential roles in the regulation of cardiovascular physiology. Though α1-ARs are less abundant in the heart than β1-ARs, activation of cardiac α1-ARs results in important biologic processes such as hypertrophy, positive inotropy, ischemic preconditioning, and protection from cell death. Data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicate that nonselectively blocking α1-ARs is associated with a twofold increase in adverse cardiac events, including heart failure and angina, suggesting that α1-AR activation might also be cardioprotective in humans. Mounting evidence implicates the α1A-AR subtype in these adaptive effects, including prevention and reversal of heart failure in animal models by α1A agonists. In this review, we summarize recent advances in our understanding of cardiac α1A-ARs.
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Affiliation(s)
- Jiandong Zhang
- McAllister Heart Institute, University of North Carolina, School of Medicine, Chapel Hill, North Carolina
| | - Paul C Simpson
- Department of Medicine and Research Service, San Francisco Veterans Affairs Medical Center and Cardiovascular Research Institute, University of California, San Francisco, California
| | - Brian C Jensen
- McAllister Heart Institute, University of North Carolina, School of Medicine, Chapel Hill, North Carolina
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9
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Kaykı-Mutlu G, Papazisi O, Palmen M, Danser AHJ, Michel MC, Arioglu-Inan E. Cardiac and Vascular α 1-Adrenoceptors in Congestive Heart Failure: A Systematic Review. Cells 2020; 9:E2412. [PMID: 33158106 PMCID: PMC7694190 DOI: 10.3390/cells9112412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 02/07/2023] Open
Abstract
As heart failure (HF) is a devastating health problem worldwide, a better understanding and the development of more effective therapeutic approaches are required. HF is characterized by sympathetic system activation which stimulates α- and β-adrenoceptors (ARs). The exposure of the cardiovascular system to the increased locally released and circulating levels of catecholamines leads to a well-described downregulation and desensitization of β-ARs. However, information on the role of α-AR is limited. We have performed a systematic literature review examining the role of both cardiac and vascular α1-ARs in HF using 5 databases for our search. All three α1-AR subtypes (α1A, α1B and α1D) are expressed in human and animal hearts and blood vessels in a tissue-dependent manner. We summarize the changes observed in HF regarding the density, signaling and responses of α1-ARs. Conflicting findings arise from different studies concerning the influence that HF has on α1-AR expression and function; in contrast to β-ARs there is no consistent evidence for down-regulation or desensitization of cardiac or vascular α1-ARs. Whether α1-ARs are a therapeutic target in HF remains a matter of debate.
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Affiliation(s)
- Gizem Kaykı-Mutlu
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey; (G.K.-M.); (E.A.-I.)
| | - Olga Papazisi
- Department of Cardiothoracic Surgery, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; (O.P.); (M.P.)
| | - Meindert Palmen
- Department of Cardiothoracic Surgery, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; (O.P.); (M.P.)
| | - A. H. Jan Danser
- Department of Internal Medicine, Division of Pharmacology, Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands;
| | - Martin C. Michel
- Department of Pharmacology, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey; (G.K.-M.); (E.A.-I.)
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10
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Klinke A, Schubert T, Müller M, Legchenko E, Zelt JGE, Shimauchi T, Napp LC, Rothman AMK, Bonnet S, Stewart DJ, Hansmann G, Rudolph V. Emerging therapies for right ventricular dysfunction and failure. Cardiovasc Diagn Ther 2020; 10:1735-1767. [PMID: 33224787 PMCID: PMC7666928 DOI: 10.21037/cdt-20-592] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/27/2020] [Indexed: 12/17/2022]
Abstract
Therapeutic options for right ventricular (RV) dysfunction and failure are strongly limited. Right heart failure (RHF) has been mostly addressed in the context of pulmonary arterial hypertension (PAH), where it is not possible to discern pulmonary vascular- and RV-directed effects of therapeutic approaches. In part, opposing pathomechanisms in RV and pulmonary vasculature, i.e., regarding apoptosis, angiogenesis and proliferation, complicate addressing RHF in PAH. Therapy effective for left heart failure is not applicable to RHF, e.g., inhibition of adrenoceptor signaling and of the renin-angiotensin system had no or only limited success. A number of experimental studies employing animal models for PAH or RV dysfunction or failure have identified beneficial effects of novel pharmacological agents, with most promising results obtained with modulators of metabolism and reactive oxygen species or inflammation, respectively. In addition, established PAH agents, in particular phosphodiesterase-5 inhibitors and soluble guanylate cyclase stimulators, may directly address RV integrity. Promising results are furthermore derived with microRNA (miRNA) and long non-coding RNA (lncRNA) blocking or mimetic strategies, which can target microvascular rarefaction, inflammation, metabolism or fibrotic and hypertrophic remodeling in the dysfunctional RV. Likewise, pre-clinical data demonstrate that cell-based therapies using stem or progenitor cells have beneficial effects on the RV, mainly by improving the microvascular system, however clinical success will largely depend on delivery routes. A particular option for PAH is targeted denervation of the pulmonary vasculature, given the sympathetic overdrive in PAH patients. Finally, acute and durable mechanical circulatory support are available for the right heart, which however has been tested mostly in RHF with concomitant left heart disease. Here, we aim to review current pharmacological, RNA- and cell-based therapeutic options and their potential to directly target the RV and to review available data for pulmonary artery denervation and mechanical circulatory support.
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Affiliation(s)
- Anna Klinke
- Clinic for General and Interventional Cardiology/Angiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Torben Schubert
- Clinic for General and Interventional Cardiology/Angiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Marion Müller
- Clinic for General and Interventional Cardiology/Angiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany
| | - Ekaterina Legchenko
- Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany
| | - Jason G. E. Zelt
- Division of Cardiology, University of Ottawa Heart Institute and the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada
| | - Tsukasa Shimauchi
- Pulmonary Hypertension Research Group, Centre de recherche de IUCPQ/Laval University, Quebec, Canada
| | - L. Christian Napp
- Department of Cardiology and Angiology, Hannover Medical School, Hannover, Germany
| | | | - Sébastien Bonnet
- Pulmonary Hypertension Research Group, Centre de recherche de IUCPQ/Laval University, Quebec, Canada
| | - Duncan J. Stewart
- Division of Cardiology, University of Ottawa Heart Institute and the Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada
| | - Georg Hansmann
- Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany
| | - Volker Rudolph
- Clinic for General and Interventional Cardiology/Angiology, Herz- und Diabeteszentrum NRW, Ruhr-Universität Bochum, Bad Oeynhausen, Germany
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11
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Myagmar BE, Ismaili T, Swigart PM, Raghunathan A, Baker AJ, Sahdeo S, Blevitt JM, Milla ME, Simpson PC. Coupling to Gq Signaling Is Required for Cardioprotection by an Alpha-1A-Adrenergic Receptor Agonist. Circ Res 2019; 125:699-706. [PMID: 31426700 DOI: 10.1161/circresaha.118.314416] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Gq signaling in cardiac myocytes is classically considered toxic. Targeting Gq directly to test this is problematic, because cardiac myocytes have many Gq-coupled receptors. OBJECTIVE Test whether Gq coupling is required for the cardioprotective effects of an alpha-1A-AR (adrenergic receptor) agonist. METHODS AND RESULTS In recombinant cells, a mouse alpha-1A-AR with a 6-residue substitution in the third intracellular loop does not couple to Gq signaling. Here we studied a knockin mouse with this alpha-1A-AR mutation. Heart alpha-1A receptor levels and antagonist affinity in the knockin were identical to wild-type. In wild-type cardiac myocytes, the selective alpha-1A agonist A61603-stimulated phosphoinositide-phospholipase C and myocyte contraction. In myocytes with the alpha-1A knockin, both A61603 effects were absent, indicating that Gq coupling was absent. Surprisingly, A61603 activation of cardioprotective ERK (extracellular signal-regulated kinase) was markedly impaired in the KI mutant myocytes, and A61603 did not protect mutant myocytes from doxorubicin toxicity in vitro. Similarly, mice with the α1A KI mutation had increased mortality after transverse aortic constriction, and A61603 did not rescue cardiac function in mice with the Gq coupling-defective alpha-1A receptor. CONCLUSIONS Gq coupling is required for cardioprotection by an alpha-1A-AR agonist. Gq signaling can be adaptive.
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Affiliation(s)
- Bat-Erdene Myagmar
- From the VA Medical Center, San Francisco, CA (B.-E.M., P.M.S., A.R., A.J.B., P.C.S.).,University of California, San Francisco (B.-E.M., A.J.B., P.C.S.)
| | - Taylor Ismaili
- Janssen Research and Development, San Diego, CA (T.I., S.S., J.M.B.)
| | - Philip M Swigart
- From the VA Medical Center, San Francisco, CA (B.-E.M., P.M.S., A.R., A.J.B., P.C.S.)
| | - Anaha Raghunathan
- From the VA Medical Center, San Francisco, CA (B.-E.M., P.M.S., A.R., A.J.B., P.C.S.)
| | - Anthony J Baker
- From the VA Medical Center, San Francisco, CA (B.-E.M., P.M.S., A.R., A.J.B., P.C.S.).,University of California, San Francisco (B.-E.M., A.J.B., P.C.S.)
| | - Sunil Sahdeo
- Janssen Research and Development, San Diego, CA (T.I., S.S., J.M.B.)
| | | | | | - Paul C Simpson
- From the VA Medical Center, San Francisco, CA (B.-E.M., P.M.S., A.R., A.J.B., P.C.S.).,University of California, San Francisco (B.-E.M., A.J.B., P.C.S.)
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12
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Cowley PM, Roberts CR, Baker AJ. Monitoring the Health Status of Mice with Bleomycin-induced Lung Injury by Using Body Condition Scoring. Comp Med 2019; 69:95-102. [PMID: 30808435 DOI: 10.30802/aalas-cm-18-000060] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Well-defined, humane endpoints aid in monitoring animal health status during disease development. Body condition scoring (BCS) is a method for assessing health status in mouse studies where wasting and death are potential endpoints. Whether BCS is useful in monitoring animals with bleomycin-induced lung injury has not been reported. Body weight (BW) is a common humane endpoint for this model, but because the lungs increase in weight as BW decreases, the animal's true physical condition could be masked when using BW as the sole endpoint criterion. Therefore, our goal here was to assess the usefulness of BCS in monitoring health status in a mouse model of lung injury. Lung injury was caused by acute instil- lation of the fibrogenic antibiotic bleomycin into the lungs through the trachea. Male C57BL/6 mice received bleomycin (0.075 U) dissolved in saline or saline alone. Bleomycin instillation led to a doubling of lung weight and decreases in both BW and BCS, compared with saline instillation. The changes in BW and BCS were significantly correlated with lung weight. When the adjusted BW was used (corrected for the increase in lung weight), the correlation was unchanged, suggesting that the increase in lung weight did not significantly mask the decrease in BW. Bleomycin instillation caused decreases in both soleus and visceral epididymal fat masses. The change in BCS was significantly correlated with both soleus and VEF mass, suggesting that BCS is reflective of the systemic loss of muscle and fat mass. Our findings suggest that BW and BCS are significantly correlated to lung injury in the bleomycin model of lung fibrosis and that BCS is an appropriate alternative humane endpoint in this mouse model.
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Affiliation(s)
- Patrick M Cowley
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University of California, San Francisco, California;,
| | - Clifford R Roberts
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University of California, San Francisco, California
| | - Anthony J Baker
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University of California, San Francisco, California
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13
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Gebert-Oberle B, Giles J, Clayton S, Tran QK. Calcium/calmodulin regulates signaling at the α 1A adrenoceptor. Eur J Pharmacol 2019; 848:70-79. [PMID: 30690001 DOI: 10.1016/j.ejphar.2019.01.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 01/23/2019] [Accepted: 01/24/2019] [Indexed: 11/16/2022]
Abstract
Cardiovascular functions are mediated by multiple 7-pass transmembrane receptors whose activation promotes contraction or relaxation of the tissues. The α1 adrenoceptor type 1A plays important roles in the control of vascular tone and myocardial contractility via Ca2+-dependent actions. Here, using novel FRET-based biosensors, we identified a novel Ca2+-dependent interaction between calmodulin (CaM) and the human α1A adrenoceptor at the juxtamembranous region of its 4th submembrane domain (SMD4JM, a.a. 333-361). SMD4JM houses the known nuclear localization signal of α1A adrenoceptor (NLS, a.a. 334-349). We found that NLS itself also interacts with CaM, but with lower affinity and Ca2+ sensitivity, indicating that full interaction between CaM and α1A receptor in this region requires segment a.a. 333-361. Combined K353Q/L356A substitutions in the non-NLS segment of SMD4JM cause a 3.5-fold reduction in the affinity of CaM-SMD4JM interaction. Overexpression of wild-type α1A adrenoceptor in cells enhances phosphorylation of the extracellular signal-regulated kinases 1/2 (ERK1/2) stimulated by A61603, while overexpression of the K353Q/L356A α1A receptor mutant significantly reduces this signal. Norepinephrine stimulates intracellular Ca2+ signals that are higher in cells overexpressing wild-type receptor but lower in cells overexpressing the K353Q/L356A receptor compared to non-transfected cells in the same microscopic environments. These data support a novel and important role for Ca2+-dependent CaM interaction at SMD4JM in α1A adrenoceptor-mediated signaling.
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Affiliation(s)
- Briana Gebert-Oberle
- Department of Physiology and Pharmacology, Des Moines University Osteopathic Medical Center, Ryan Hall 258, 3200 Grand Avenue, Des Moines, IA 50312, United States
| | - Jennifer Giles
- Department of Physiology and Pharmacology, Des Moines University Osteopathic Medical Center, Ryan Hall 258, 3200 Grand Avenue, Des Moines, IA 50312, United States
| | - Sarah Clayton
- Department of Physiology and Pharmacology, Des Moines University Osteopathic Medical Center, Ryan Hall 258, 3200 Grand Avenue, Des Moines, IA 50312, United States
| | - Quang-Kim Tran
- Department of Physiology and Pharmacology, Des Moines University Osteopathic Medical Center, Ryan Hall 258, 3200 Grand Avenue, Des Moines, IA 50312, United States.
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14
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Viswanathan G, Mamazhakypov A, Schermuly RT, Rajagopal S. The Role of G Protein-Coupled Receptors in the Right Ventricle in Pulmonary Hypertension. Front Cardiovasc Med 2018; 5:179. [PMID: 30619886 PMCID: PMC6305072 DOI: 10.3389/fcvm.2018.00179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/30/2018] [Indexed: 12/14/2022] Open
Abstract
Pressure overload of the right ventricle (RV) in pulmonary arterial hypertension (PAH) leads to RV remodeling and failure, an important determinant of outcome in patients with PAH. Several G protein-coupled receptors (GPCRs) are differentially regulated in the RV myocardium, contributing to the pathogenesis of RV adverse remodeling and dysfunction. Many pharmacological agents that target GPCRs have been demonstrated to result in beneficial effects on left ventricular (LV) failure, such as beta-adrenergic receptor and angiotensin receptor antagonists. However, the role of such drugs on RV remodeling and performance is not known at this time. Moreover, many of these same receptors are also expressed in the pulmonary vasculature, which could result in complex effects in PAH. This manuscript reviews the role of GPCRs in the RV remodeling and dysfunction and discusses activating and blocking GPCR signaling to potentially attenuate remodeling while promoting improvements of RV function in PAH.
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Affiliation(s)
- Gayathri Viswanathan
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, United States
| | - Argen Mamazhakypov
- Department of Internal Medicine, Member of the German Center for Lung Research (DZL), Justus Liebig University of Giessen, Giessen, Germany
| | - Ralph T Schermuly
- Department of Internal Medicine, Member of the German Center for Lung Research (DZL), Justus Liebig University of Giessen, Giessen, Germany
| | - Sudarshan Rajagopal
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, NC, United States
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15
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Janssen PM, Canan BD, Kilic A, Whitson BA, Baker AJ. Human Myocardium Has a Robust α1A-Subtype Adrenergic Receptor Inotropic Response. J Cardiovasc Pharmacol 2018; 72:136-142. [PMID: 29923888 PMCID: PMC6126952 DOI: 10.1097/fjc.0000000000000604] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent studies report that a single subtype of α1-adrenergic receptor (α1-AR), the α1A-subtype, mediates robust cardioprotective effects in multiple experimental models of heart failure, suggesting that the α1A-subtype is a potential therapeutic target for an agonist to treat heart failure. Moreover, we recently found that the α1A-subtype is present in human heart. The goal of this study was to assess the inotropic response mediated by the α1A-subtype in human myocardium, and to determine whether the response is downregulated in myocardium from failing human heart. We measured in vitro contractile responses of cardiac muscle preparations (trabeculae) isolated from the right ventricle from nonfailing and failing human hearts. Addition of the α1A-subtype agonist A61603 (100 nM) resulted in a large positive inotropic response (force increased ≈ 2-fold). This response represented ≈70% of the response mediated by the β-adrenergic receptor agonist isoproterenol (1 μM). Moreover, in myocardium from failing hearts, α1A-subtype responses remained robust, and only slightly reduced relative to nonfailing hearts. We conclude that α1A-subtype-mediated inotropy could represent a significant source of inotropic support in the human heart. Furthermore, the α1A-subtype remains functional in myocardium from failing human hearts and thus, might be a therapeutic target to support cardioprotective effects in patients with heart failure.
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Affiliation(s)
- Paul M.L. Janssen
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Benjamin D. Canan
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| | - Ahmet Kilic
- Department of Surgery, The Ohio State University, Columbus, Ohio
| | - Bryan A Whitson
- Department of Surgery, The Ohio State University, Columbus, Ohio
| | - Anthony J. Baker
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, Univ. Calif. San Francisco, San Francisco
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16
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Philip JL, Pewowaruk RJ, Chen CS, Tabima DM, Beard DA, Baker AJ, Chesler NC. Impaired Myofilament Contraction Drives Right Ventricular Failure Secondary to Pressure Overload: Model Simulations, Experimental Validation, and Treatment Predictions. Front Physiol 2018; 9:731. [PMID: 29997518 PMCID: PMC6030352 DOI: 10.3389/fphys.2018.00731] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/25/2018] [Indexed: 12/31/2022] Open
Abstract
Introduction: Pulmonary hypertension (PH) causes pressure overload leading to right ventricular failure (RVF). Myocardial structure and myocyte mechanics are altered in RVF but the direct impact of these cellular level factors on organ level function remain unclear. A computational model of the cardiovascular system that integrates cellular function into whole organ function has recently been developed. This model is a useful tool for investigating how changes in myocyte structure and mechanics contribute to organ function. We use this model to determine how measured changes in myocyte and myocardial mechanics contribute to RVF at the organ level and predict the impact of myocyte-targeted therapy. Methods: A multiscale computational framework was tuned to model PH due to bleomycin exposure in mice. Pressure overload was modeled by increasing the pulmonary vascular resistance (PVR) and decreasing pulmonary artery compliance (CPA). Myocardial fibrosis and the impairment of myocyte maximum force generation (Fmax) were simulated by increasing the collagen content (↑PVR + ↓CPA + fibrosis) and decreasing Fmax (↑PVR + ↓CPA + fibrosis + ↓Fmax). A61603 (A6), a selective α1A-subtype adrenergic receptor agonist, shown to improve Fmax was simulated to explore targeting myocyte generated Fmax in PH. Results: Increased afterload (RV systolic pressure and arterial elastance) in simulations matched experimental results for bleomycin exposure. Pressure overload alone (↑PVR + ↓CPA) caused decreased RV ejection fraction (EF) similar to experimental findings but preservation of cardiac output (CO). Myocardial fibrosis in the setting of pressure overload (↑PVR + ↓PAC + fibrosis) had minimal impact compared to pressure overload alone. Including impaired myocyte function (↑PVR + ↓PAC + fibrosis + ↓Fmax) reduced CO, similar to experiment, and impaired EF. Simulations predicted that A6 treatment preserves EF and CO despite maintained RV pressure overload. Conclusion: Multiscale computational modeling enabled prediction of the contribution of cellular level changes to whole organ function. Impaired Fmax is a key feature that directly contributes to RVF. Simulations further demonstrate the therapeutic benefit of targeting Fmax, which warrants additional study. Future work should incorporate growth and remodeling into the computational model to enable prediction of the multiscale drivers of the transition from dysfunction to failure.
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Affiliation(s)
- Jennifer L. Philip
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Department of Surgery, University of Wisconsin–Madison, Madison, WI, United States
| | - Ryan J. Pewowaruk
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
| | - Claire S. Chen
- Department of Mechanical Engineering, University of Wisconsin–Madison, Madison, WI, United States
| | - Diana M. Tabima
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
| | - Daniel A. Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Anthony J. Baker
- San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States
- Department of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Naomi C. Chesler
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Department of Mechanical Engineering, University of Wisconsin–Madison, Madison, WI, United States
- Department of Medicine, University of Wisconsin–Madison, Madison, WI, United States
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17
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Cowley PM, Wang G, Joshi S, Swigart PM, Lovett DH, Simpson PC, Baker AJ. α 1A-Subtype adrenergic agonist therapy for the failing right ventricle. Am J Physiol Heart Circ Physiol 2017; 313:H1109-H1118. [PMID: 28822963 DOI: 10.1152/ajpheart.00153.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/06/2017] [Accepted: 08/10/2017] [Indexed: 11/22/2022]
Abstract
Failure of the right ventricle (RV) is a serious disease with a poor prognosis and limited treatment options. Signaling by α1-adrenergic receptors (α1-ARs), in particular the α1A-subtype, mediate cardioprotective effects in multiple heart failure models. Recent studies have shown that chronic treatment with the α1A-subtype agonist A61603 improves function and survival in a model of left ventricular failure. The goal of the present study was to determine if chronic A61603 treatment is beneficial in a RV failure model. We used tracheal instillation of the fibrogenic antibiotic bleomycin in mice to induce pulmonary fibrosis, pulmonary hypertension, and RV failure within 2 wk. Some mice were chronically treated with a low dose of A61603 (10 ng·kg-1·day-1). In the bleomycin model of RV failure, chronic A61603 treatment was associated with improved RV fractional shortening and greater in vitro force development by RV muscle preparations. Cell injury markers were reduced with A61603 treatment (serum cardiac troponin I, RV fibrosis, and expression of matrix metalloproteinase-2). RV oxidative stress was reduced (using the probes dihydroethidium and 4-hydroxynonenal). Consistent with lowered RV oxidative stress, A61603 was associated with an increased level of the cellular antioxidant superoxide dismutase 1 and a lower level of the prooxidant NAD(P)H oxidase isoform NOX4. In summary, in the bleomycin model of RV failure, chronic A61603 treatment reduced RV oxidative stress, RV myocyte necrosis, and RV fibrosis and increased both RV function and in vitro force development. These findings suggest that in the context of pulmonary fibrosis, the α1A-subtype is a potential therapeutic target to treat the failing RV.NEW & NOTEWORTHY Right ventricular (RV) failure is a serious disease with a poor prognosis and no effective treatments. In the mouse bleomycin model of RV failure, we tested the efficacy of a treatment using the α1A-adrenergic receptor subtype agonist A61603. Chronic A61603 treatment improved RV contraction and reduced multiple indexes of RV injury, suggesting that the α1A-subtype is a therapeutic target to treat RV failure.
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Affiliation(s)
- Patrick M Cowley
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - Guanying Wang
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - Sunil Joshi
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - Philip M Swigart
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - David H Lovett
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - Paul C Simpson
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
| | - Anthony J Baker
- Veterans Affairs Medical Center, San Francisco, California, and Department of Medicine, University of California, San Francisco, California
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18
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Abstract
There are 2 α1-ARs on cardiac myocytes: α1A and α1B. α1A adrenergic receptors serve important cardioprotective roles and do not mediate cardiac hypertrophy. Dabuzalgron, an oral α1A-AR agonist developed for the treatment of urinary incontinence and tolerated well in Phase 2 clinical trials, protects against doxorubicin-induced cardiotoxicity in vivo. Dabuzalgron enhances contractile function, regulates transcription of genes related to energy production and mitochondrial function, and preserves myocardial ATP content after doxorubicin. Activation of α1A-ARs on cardiomyocytes protects against doxorubicin cytotoxicity and enhances mitochondrial function in vitro. These cytoprotective effects likely are mediated by activation of ERK 1/2. Future studies will explore whether dabuzalgron, a well-tolerated oral α1A-AR agonist, might be repurposed to treat heart failure.
Alpha-1 adrenergic receptors (α1-ARs) play adaptive and protective roles in the heart. Dabuzalgron is an oral selective α1A-AR agonist that was well tolerated in multiple clinical trials of treatment for urinary incontinence, but has never been used to treat heart disease in humans or animal models. In this study, the authors administered dabuzalgron to mice treated with doxorubicin (DOX), a widely used chemotherapeutic agent with dose-limiting cardiotoxicity that can lead to heart failure (HF). Dabuzalgron protected against DOX-induced cardiotoxicity, likely by preserving mitochondrial function. These results suggest that activating cardiac α1A-ARs with dabuzalgron, a well-tolerated oral agent, might represent a novel approach to treating HF.
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19
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Montgomery MD, Chan T, Swigart PM, Myagmar BE, Dash R, Simpson PC. An Alpha-1A Adrenergic Receptor Agonist Prevents Acute Doxorubicin Cardiomyopathy in Male Mice. PLoS One 2017; 12:e0168409. [PMID: 28081170 PMCID: PMC5231318 DOI: 10.1371/journal.pone.0168409] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023] Open
Abstract
Alpha-1 adrenergic receptors mediate adaptive effects in the heart and cardiac myocytes, and a myocyte survival pathway involving the alpha-1A receptor subtype and ERK activation exists in vitro. However, data in vivo are limited. Here we tested A61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl]methanesulfonamide), a selective imidazoline agonist for the alpha-1A. A61603 was the most potent alpha-1-agonist in activating ERK in neonatal rat ventricular myocytes. A61603 activated ERK in adult mouse ventricular myocytes and protected the cells from death caused by the anthracycline doxorubicin. A low dose of A61603 (10 ng/kg/d) activated ERK in the mouse heart in vivo, but did not change blood pressure. In male mice, concurrent subcutaneous A61603 infusion at 10 ng/kg/d for 7 days after a single intraperitoneal dose of doxorubicin (25 mg/kg) increased survival, improved cardiac function, heart rate, and cardiac output by echocardiography, and reduced cardiac cell necrosis and apoptosis and myocardial fibrosis. All protective effects were lost in alpha-1A-knockout mice. In female mice, doxorubicin at doses higher than in males (35-40 mg/kg) caused less cardiac toxicity than in males. We conclude that the alpha-1A-selective agonist A61603, via the alpha-1A adrenergic receptor, prevents doxorubicin cardiomyopathy in male mice, supporting the theory that alpha-1A adrenergic receptor agonists have potential as novel heart failure therapies.
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Affiliation(s)
- Megan D. Montgomery
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Trevor Chan
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Philip M. Swigart
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Bat-erdene Myagmar
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Rajesh Dash
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Paul C. Simpson
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
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20
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Willis MS, Ilaiwy A, Montgomery MD, Simpson PC, Jensen BC. The alpha-1A adrenergic receptor agonist A61603 reduces cardiac polyunsaturated fatty acid and endocannabinoid metabolites associated with inflammation in vivo. Metabolomics 2016; 12:155. [PMID: 28533737 PMCID: PMC5437747 DOI: 10.1007/s11306-016-1097-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Alpha-1-adrenergic receptors (α1-ARs) are G-protein coupled receptors (GPCRs) with three highly homologous subtypes (α1A, α1B, and α1D). Of these three subtypes, only the α1A and α1B are expressed in the heart. Multiple pre-clinical models of heart injury demonstrate cardioprotective roles for the α1A. Non-selective α1-AR activation promotes glycolysis in the heart, but the functional α1-AR subtype and broader metabolic effects have not been studied. OBJECTIVES Given the high metabolic demands of the heart and previous evidence indicating benefit from α1A activation, we chose to investigate the effects of α1A activation on the cardiac metabolome in vivo. METHODS Mice were treated for one week with a low, subpressor dose of A61603, a highly selective and potent α1A agonist. Cardiac tissue and serum were analyzed using a non-targeted metabolomics approach. RESULTS We identified previously unrecognized metabolic responses to α1A activation, most notably broad reduction in the abundance of polyunsaturated fatty acids (PUFAs) and endocannabinoids (ECs). CONCLUSION Given the well characterized roles of PUFAs and ECs in inflammatory pathways, these findings suggest a possible role for cardiac α1A-ARs in the regulation of inflammation and may offer novel insight into the mechanisms underlying the cardioprotective benefit of selective pharmacologic α1A activation.
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Affiliation(s)
- Monte S. Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC USA
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC USA
| | - Amro Ilaiwy
- Sarah W. Stedman Nutrition and Metabolism Center, Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC, USA
- Division of Endocrinology, Metabolism, and Nutrition, Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | | | - Paul C. Simpson
- VA Medical Center and University of California, San Francisco, CA, USA
| | - Brian C. Jensen
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC USA
- Department of Internal Medicine, Division of Cardiology University of North Carolina, Chapel Hill, NC, USA
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21
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Thomas RC, Cowley PM, Singh A, Myagmar BE, Swigart PM, Baker AJ, Simpson PC. The Alpha-1A Adrenergic Receptor in the Rabbit Heart. PLoS One 2016; 11:e0155238. [PMID: 27258143 PMCID: PMC4892533 DOI: 10.1371/journal.pone.0155238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 04/26/2016] [Indexed: 11/20/2022] Open
Abstract
The alpha-1A-adrenergic receptor (AR) subtype is associated with cardioprotective signaling in the mouse and human heart. The rabbit is useful for cardiac disease modeling, but data on the alpha-1A in the rabbit heart are limited. Our objective was to test for expression and function of the alpha-1A in rabbit heart. By quantitative real-time reverse transcription PCR (qPCR) on mRNA from ventricular myocardium of adult male New Zealand White rabbits, the alpha-1B was 99% of total alpha-1-AR mRNA, with <1% alpha-1A and alpha-1D, whereas alpha-1A mRNA was over 50% of total in brain and liver. Saturation radioligand binding identified ~4 fmol total alpha-1-ARs per mg myocardial protein, with 17% alpha-1A by competition with the selective antagonist 5-methylurapidil. The alpha-1D was not detected by competition with BMY-7378, indicating that 83% of alpha-1-ARs were alpha-1B. In isolated left ventricle and right ventricle, the selective alpha-1A agonist A61603 stimulated a negative inotropic effect, versus a positive inotropic effect with the nonselective alpha-1-agonist phenylephrine and the beta-agonist isoproterenol. Blood pressure assay in conscious rabbits using an indwelling aortic telemeter showed that A61603 by bolus intravenous dosing increased mean arterial pressure by 20 mm Hg at 0.14 μg/kg, 10-fold lower than norepinephrine, and chronic A61603 infusion by iPRECIO programmable micro Infusion pump did not increase BP at 22 μg/kg/d. A myocardial slice model useful in human myocardium and an anthracycline cardiotoxicity model useful in mouse were both problematic in rabbit. We conclude that alpha-1A mRNA is very low in rabbit heart, but the receptor is present by binding and mediates a negative inotropic response. Expression and function of the alpha-1A in rabbit heart differ from mouse and human, but the vasopressor response is similar to mouse.
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Affiliation(s)
- R. Croft Thomas
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
| | - Patrick M. Cowley
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
| | - Abhishek Singh
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
| | - Bat-Erdene Myagmar
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
| | - Philip M. Swigart
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
| | - Anthony J. Baker
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
| | - Paul C. Simpson
- Department of Medicine, Cardiology Division, and Research Service, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States of America
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22
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Pradhan RK, Feigl EO, Gorman MW, Brengelmann GL, Beard DA. Open-loop (feed-forward) and feedback control of coronary blood flow during exercise, cardiac pacing, and pressure changes. Am J Physiol Heart Circ Physiol 2016; 310:H1683-94. [PMID: 27037372 DOI: 10.1152/ajpheart.00663.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 03/30/2016] [Indexed: 11/22/2022]
Abstract
A control system model was developed to analyze data on in vivo coronary blood flow regulation and to probe how different mechanisms work together to control coronary flow from rest to exercise, and under a variety of experimental conditions, including cardiac pacing and with changes in coronary arterial pressure (autoregulation). In the model coronary flow is determined by the combined action of a feedback pathway signal that is determined by the level of plasma ATP in coronary venous blood, an adrenergic open-loop (feed-forward) signal that increases with exercise, and a contribution of pressure-mediated myogenic control. The model was identified based on data from exercise experiments where myocardial oxygen extraction, coronary flow, cardiac interstitial norepinephrine concentration, and arterial and coronary venous plasma ATP concentrations were measured during control and during adrenergic and purinergic receptor blockade conditions. The identified model was used to quantify the relative contributions of open-loop and feedback pathways and to illustrate the degree of redundancy in the control of coronary flow. The results indicate that the adrenergic open-loop control component is responsible for most of the increase in coronary blood flow that occurs during high levels of exercise. However, the adenine nucleotide-mediated metabolic feedback control component is essential. The model was evaluated by predicting coronary flow in cardiac pacing and autoregulation experiments with reasonable fits to the data. The analysis shows that a model in which coronary venous plasma adenine nucleotides are a signal in local metabolic feedback control of coronary flow is consistent with the available data.
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Affiliation(s)
- Ranjan K Pradhan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and
| | - Eric O Feigl
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Mark W Gorman
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - George L Brengelmann
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Daniel A Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and
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