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Zhang J, Sandroni PB, Huang W, Gao X, Oswalt L, Schroder MA, Lee S, Shih YYI, Huang HYS, Swigart PM, Myagmar BE, Simpson PC, Rossi JS, Schisler JC, Jensen BC. Cardiomyocyte Alpha-1A Adrenergic Receptors Mitigate Postinfarct Remodeling and Mortality by Constraining Necroptosis. JACC Basic Transl Sci 2024; 9:78-96. [PMID: 38362342 PMCID: PMC10864988 DOI: 10.1016/j.jacbts.2023.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 08/26/2023] [Accepted: 08/29/2023] [Indexed: 02/17/2024]
Abstract
Clinical studies have shown that α1-adrenergic receptor antagonists (α-blockers) are associated with increased heart failure risk. The mechanism underlying that hazard and whether it arises from direct inhibition of cardiomyocyte α1-ARs or from systemic effects remain unclear. To address these issues, we created a mouse with cardiomyocyte-specific deletion of the α1A-AR subtype and found that it experienced 70% mortality within 7 days of myocardial infarction driven, in part, by excessive activation of necroptosis. We also found that patients taking α-blockers at our center were at increased risk of death after myocardial infarction, providing clinical correlation for our translational animal models.
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Affiliation(s)
- Jiandong Zhang
- Division of Cardiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Peyton B. Sandroni
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
| | - Wei Huang
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Xiaohua Gao
- Department of Epidemiology, University of North Carolina Gillings School of Public Health, Chapel Hill, North Carolina, USA
| | - Leah Oswalt
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Melissa A. Schroder
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - SungHo Lee
- Center for Animal MRI, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Yen-Yu I. Shih
- Center for Animal MRI, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Hsiao-Ying S. Huang
- Mechanical and Aerospace Engineering Department, North Carolina State University, Raleigh, North Carolina, USA
| | - Philip M. Swigart
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
- San Francisco VA Medical Center, San Francisco, California, USA
| | - Bat E. Myagmar
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
- San Francisco VA Medical Center, San Francisco, California, USA
| | - Paul C. Simpson
- Department of Medicine, University of California-San Francisco, San Francisco, California, USA
- San Francisco VA Medical Center, San Francisco, California, USA
| | - Joseph S. Rossi
- Division of Cardiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Jonathan C. Schisler
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Brian C. Jensen
- Division of Cardiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- UNC McAllister Heart Institute, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina, USA
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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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Kaidonis X, Niu W, Chan AY, Kesteven S, Wu J, Iismaa SE, Vatner S, Feneley M, Graham RM. Adaptation to exercise-induced stress is not dependent on cardiomyocyte α 1A-adrenergic receptors. J Mol Cell Cardiol 2021; 155:78-87. [PMID: 33647309 DOI: 10.1016/j.yjmcc.2021.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/31/2022]
Abstract
The 'fight or flight' response to physiological stress involves sympathetic nervous system activation, catecholamine release and adrenergic receptor stimulation. In the heart, this induces positive inotropy, previously attributed to the β1-adrenergic receptor subtype. However, the role of the α1A-adrenergic receptor, which has been suggested to be protective in cardiac pathology, has not been investigated in the setting of physiological stress. To explore this, we developed a tamoxifen-inducible, cardiomyocyte-specific α1A-adrenergic receptor knock-down mouse model, challenged mice to four weeks of endurance swim training and assessed cardiac outcomes. With 4-OH tamoxifen treatment, expression of the α1A-adrenergic receptor was knocked down by 80-89%, without any compensatory changes in the expression of other adrenergic receptors, or changes to baseline cardiac structure and function. Swim training caused eccentric hypertrophy, regardless of genotype, demonstrated by an increase in heart weight/tibia length ratio (30% and 22% in vehicle- and tamoxifen-treated animals, respectively) and an increase in left ventricular end diastolic volume (30% and 24% in vehicle- and tamoxifen-treated animals, respectively) without any change in the wall thickness/chamber radius ratio. Consistent with physiological hypertrophy, there was no increase in fetal gene program (Myh7, Nppa, Nppb or Acta1) expression. In response to exercise-induced volume overload, stroke volume (39% and 30% in vehicle- and tamoxifen-treated animals, respectively), cardiac output/tibia length ratio (41% in vehicle-treated animals) and stroke work (61% and 33% in vehicle- and tamoxifen-treated animals, respectively) increased, regardless of genotype. These findings demonstrate that cardiomyocyte α1A-adrenergic receptors are not necessary for cardiac adaptation to endurance exercise stress and their acute ablation is not deleterious.
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Affiliation(s)
- Xenia Kaidonis
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Wenxing Niu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Medical Sciences, University of NSW, Kensington, NSW 2052, Australia
| | - Andrea Y Chan
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Scott Kesteven
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Jianxin Wu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Siiri E Iismaa
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Stephen Vatner
- Cardiovascular Research Institute, Dept. of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Michael Feneley
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Robert M Graham
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia.
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El-Mas MM, Abdel-Rahman AA. Role of Alcohol Oxidative Metabolism in Its Cardiovascular and Autonomic Effects. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1193:1-33. [PMID: 31368095 PMCID: PMC8034813 DOI: 10.1007/978-981-13-6260-6_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.
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Affiliation(s)
- Mahmoud M El-Mas
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Abdel A Abdel-Rahman
- Department of Pharmacology and Toxicology, The Brody School of Medicine, East Carolina University, Greenville, NC, USA.
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Iismaa SE, Li M, Kesteven S, Wu J, Chan AY, Holman SR, Calvert JW, Haq AU, Nicks AM, Naqvi N, Husain A, Feneley MP, Graham RM. Cardiac hypertrophy limits infarct expansion after myocardial infarction in mice. Sci Rep 2018; 8:6114. [PMID: 29666426 PMCID: PMC5904135 DOI: 10.1038/s41598-018-24525-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/22/2018] [Indexed: 01/19/2023] Open
Abstract
We have previously demonstrated that adult transgenic C57BL/6J mice with CM-restricted overexpression of the dominant negative W v mutant protein (dn-c-kit-Tg) respond to pressure overload with robust cardiomyocyte (CM) cell cycle entry. Here, we tested if outcomes after myocardial infarction (MI) due to coronary artery ligation are improved in this transgenic model. Compared to non-transgenic littermates (NTLs), adult male dn-c-kit-Tg mice displayed CM hypertrophy and concentric left ventricular (LV) hypertrophy in the absence of an increase in workload. Stroke volume and cardiac output were preserved and LV wall stress was markedly lower than that in NTLs, leading to a more energy-efficient heart. In response to MI, infarct size in adult (16-week old) dn-c-kit-Tg hearts was similar to that of NTL after 24 h but was half that in NTL hearts 12 weeks post-MI. Cumulative CM cell cycle entry was only modestly increased in dn-c-kit-Tg hearts. However, dn-c-kit-Tg mice were more resistant to infarct expansion, adverse LV remodelling and contractile dysfunction, and suffered no early death from LV rupture, relative to NTL mice. Thus, pre-existing cardiac hypertrophy lowers wall stress in dn-c-kit-Tg hearts, limits infarct expansion and prevents death from myocardial rupture.
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Affiliation(s)
- Siiri E Iismaa
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ming Li
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
- Cardiac Regeneration Research Institute, Wenzhou Medical University, Wenzhou, 325035, China
| | - Scott Kesteven
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - Jianxin Wu
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - Andrea Y Chan
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - Sara R Holman
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - John W Calvert
- Department of Surgery, Emory University School of Medicine, Atlanta, GA, 30308, USA
| | - Ahtesham Ul Haq
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - Amy M Nicks
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
| | - Nawazish Naqvi
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Ahsan Husain
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Michael P Feneley
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
| | - Robert M Graham
- Division of Molecular Cardiology and Biophysics, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia.
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2052, Australia.
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Headrick JP, Peart JN, Budiono BP, Shum DH, Neumann DL, Stapelberg NJ. The heartbreak of depression: ‘Psycho-cardiac’ coupling in myocardial infarction. J Mol Cell Cardiol 2017; 106:14-28. [DOI: 10.1016/j.yjmcc.2017.03.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/27/2017] [Accepted: 03/29/2017] [Indexed: 12/25/2022]
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Zhao X, Balaji P, Pachon R, Beniamen DM, Vatner DE, Graham RM, Vatner SF. Overexpression of Cardiomyocyte α1A-Adrenergic Receptors Attenuates Postinfarct Remodeling by Inducing Angiogenesis Through Heterocellular Signaling. Arterioscler Thromb Vasc Biol 2015; 35:2451-9. [PMID: 26338300 DOI: 10.1161/atvbaha.115.305919] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 08/19/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Stimulation of cardiac α1A-adrenergic receptors (α1A-AR) has been proposed for treatment of heart failure, since it increases myocardial contractility. We investigated a different mechanism, induction of angiogenesis. APPROACH AND RESULTS Four to 6 weeks after permanent coronary artery occlusion, transgenic rats with cardiomyocyte-specific α1A-adrenergic receptor overexpression had less remodeling than their nontransgenic littermates, with less fibrosis, hypertrophy and lung weight, and preserved left ventricular ejection fraction and wall stress (all P<0.05). Coronary blood flow, measured with microspheres, increased in the infarct zone in transgenic rats compared with nontransgenic littermates (1.4±0.2 versus 0.5±0.08 mL min(-1) g(-1); P<0.05), which is consistent with angiogenesis, as reflected by a 20% increase in capillary density in the zone adjacent to the infarct. The question arose, how does transgenic overexpression of a gene in cardiomyocytes induce angiogenesis? We identified a paracrine mechanism, whereby vascular endothelial growth factor-A mRNA and protein were increased in isolated transgenic cardiomyocytes and also by nontransgenic littermate cardiomyocytes treated with an α1A-agonist, resulting in angiogenesis. Conditioned medium from cultured cardiomyocytes treated with an α1A agonist enhanced human umbilical vein endothelial cell tubule formation, which was blocked by an anti-vascular endothelial growth factor-A antibody. Moreover, improved cardiac function, blood flow, and increased capillary density after chronic coronary artery occlusion in transgenic rats were blocked by either a mitogen ERK kinase (MEK) or a vascular endothelial growth factor-A inhibitor. CONCLUSION Cardiomyocyte-specific overexpression of the α1A-adrenergic receptors resulted in enhanced MEK-dependent cardiomyocyte vascular endothelial growth factor-A expression, which stimulates angiogenesis via a paracrine mechanism involving heterocellular cardiomyocyte/endothelial cell signaling, protecting against remodeling and heart failure after chronic coronary artery occlusion.
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Affiliation(s)
- Xin Zhao
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Poornima Balaji
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Ronald Pachon
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Daniella M Beniamen
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Dorothy E Vatner
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Robert M Graham
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.)
| | - Stephen F Vatner
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers-New Jersey Medical School, Newark (X.Z., R.P., D.E.V., S.F.V.); and Victor Chang Cardiac Research Institute and Faculty of Medicine and Life Sciences, University of New South Wales, Sydney, New South Wales, Australia (P.B., D.M.B., R.M.G.).
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Ibrahim BM, Fan M, Abdel-Rahman AA. Oxidative stress and autonomic dysregulation contribute to the acute time-dependent myocardial depressant effect of ethanol in conscious female rats. Alcohol Clin Exp Res 2014; 38:1205-15. [PMID: 24754626 DOI: 10.1111/acer.12363] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 12/23/2013] [Indexed: 12/01/2022]
Abstract
BACKGROUND The molecular mechanisms of the acute hypotensive and indirectly assessed cardiac depressant effect of ethanol (EtOH)-evoked myocardial depression and hypotension in female rats are not known. We tested the hypothesis that a time-dependent myocardial depression caused by EtOH is initiated by its direct and indirect (cardiac vagal dominance) effects and is exacerbated by gradual development of oxidative stress. METHODS In conscious female rats, we directly measured left ventricular developed pressure (LVDP), the maximal rise of ventricular pressure over time (dP/dtmax ), blood pressure (BP), heart rate (HR), and sympathovagal activity following intragastric EtOH (1 g/kg) or water over 90 minutes. Catalytic activity of acetaldehyde (ACA)-generating (alcohol dehydrogenase [ADH] and catalase) and eliminating aldehyde dehydrogenase [ALDH2] enzymes along with mediators of oxidative stress were measured in myocardial tissues collected at 30, 60, or 90 minutes after EtOH or water. RESULTS EtOH reduced myocardial function (LVDP and dP/dtmax ) within 5 to 10 minutes before the steady fall in BP in conscious proestrus rats. Further, EtOH shifted the sympathovagal balance, analyzed by spectral analysis of high frequency and low frequency of interbeat intervals, toward vagal dominance. Prior vagal blockade (atropine) or antioxidant (tempol) treatment attenuated EtOH-evoked myocardial depression and hypotension. Ex vivo studies revealed time-dependent: (i) enhancement of ADH, but not ALDH2 activity (indicative of elevated ACA levels), (ii) increases in phosphorylated Akt and ERK1/2, NADPH-oxidase activity, reactive oxygen species, malondialdehyde, and 4-hydroxy-2-nonenal-modified proteins. These molecular responses along with reduced myocardial catalase activity were most evident at 90 minutes post-EtOH when the reductions in cardiac function and BP reached their nadir. CONCLUSIONS Vagal dominance and time-dependent myocardial oxidative stress along with the accumulation of cardiotoxic aldehydes mediate EtOH-evoked myocardial dysfunction and hypotension in conscious proestrus female rats.
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Affiliation(s)
- Badr M Ibrahim
- Department of Pharmacology and Toxicology (BMI, MF, AAR-R), Brody School of Medicine, East Carolina University, Greenville, North Carolina
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Alpha-1-adrenergic receptors in heart failure: the adaptive arm of the cardiac response to chronic catecholamine stimulation. J Cardiovasc Pharmacol 2014; 63:291-301. [PMID: 24145181 DOI: 10.1097/fjc.0000000000000032] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alpha-1-adrenergic receptors (ARs) are G protein-coupled receptors activated by catecholamines. The alpha-1A and alpha-1B subtypes are expressed in mouse and human myocardium, whereas the alpha-1D protein is found only in coronary arteries. There are far fewer alpha-1-ARs than beta-ARs in the nonfailing heart, but their abundance is maintained or increased in the setting of heart failure, which is characterized by pronounced chronic elevation of catecholamines and beta-AR dysfunction. Decades of evidence from gain and loss-of-function studies in isolated cardiac myocytes and numerous animal models demonstrate important adaptive functions for cardiac alpha-1-ARs to include physiological hypertrophy, positive inotropy, ischemic preconditioning, and protection from cell death. Clinical trial data indicate that blocking alpha-1-ARs is associated with incident heart failure in patients with hypertension. Collectively, these findings suggest that alpha-1-AR activation might mitigate the well-recognized toxic effects of beta-ARs in the hyperadrenergic setting of chronic heart failure. Thus, exogenous cardioselective activation of alpha-1-ARs might represent a novel and viable approach to the treatment of heart failure.
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Yu ZY, Tan JC, McMahon AC, Iismaa SE, Xiao XH, Kesteven SH, Reichelt ME, Mohl MC, Smith NJ, Fatkin D, Allen D, Head SI, Graham RM, Feneley MP. RhoA/ROCK signaling and pleiotropic α1A-adrenergic receptor regulation of cardiac contractility. PLoS One 2014; 9:e99024. [PMID: 24919197 PMCID: PMC4053326 DOI: 10.1371/journal.pone.0099024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/09/2014] [Indexed: 11/18/2022] Open
Abstract
Aims To determine the mechanisms by which the α1A-adrenergic receptor (AR) regulates cardiac contractility. Background We reported previously that transgenic mice with cardiac-restricted α1A-AR overexpression (α1A-TG) exhibit enhanced contractility but not hypertrophy, despite evidence implicating this Gαq/11-coupled receptor in hypertrophy. Methods Contractility, calcium (Ca2+) kinetics and sensitivity, and contractile proteins were examined in cardiomyocytes, isolated hearts and skinned fibers from α1A-TG mice (170-fold overexpression) and their non-TG littermates (NTL) before and after α1A-AR agonist stimulation and blockade, angiotensin II (AngII), and Rho kinase (ROCK) inhibition. Results Hypercontractility without hypertrophy with α1A-AR overexpression is shown to result from increased intracellular Ca2+ release in response to agonist, augmenting the systolic amplitude of the intracellular Ca2+ concentration [Ca2+]i transient without changing resting [Ca2+]i. In the absence of agonist, however, α1A-AR overexpression reduced contractility despite unchanged [Ca2+]i. This hypocontractility is not due to heterologous desensitization: the contractile response to AngII, acting via its Gαq/11-coupled receptor, was unaltered. Rather, the hypocontractility is a pleiotropic signaling effect of the α1A-AR in the absence of agonist, inhibiting RhoA/ROCK activity, resulting in hypophosphorylation of both myosin phosphatase targeting subunit 1 (MYPT1) and cardiac myosin light chain 2 (cMLC2), reducing the Ca2+ sensitivity of the contractile machinery: all these effects were rapidly reversed by selective α1A-AR blockade. Critically, ROCK inhibition in normal hearts of NTLs without α1A-AR overexpression caused hypophosphorylation of both MYPT1 and cMLC2, and rapidly reduced basal contractility. Conclusions We report for the first time pleiotropic α1A-AR signaling and the physiological role of RhoA/ROCK signaling in maintaining contractility in the normal heart.
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Affiliation(s)
- Ze-Yan Yu
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Ju-Chiat Tan
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Aisling C. McMahon
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
| | - Siiri E. Iismaa
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Xiao-Hui Xiao
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | | | | | - Marion C. Mohl
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Nicola J. Smith
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - David Allen
- Physiology Department, University of Sydney, Sydney, Australia
| | - Stewart I. Head
- Physiology Department, University of New South Wales, Sydney, Australia
| | - Robert M. Graham
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Michael P. Feneley
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- * E-mail:
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Ischemic Postconditioning Reduces Infarct Size Through the α1-Adrenergic Receptor Pathway. J Cardiovasc Pharmacol 2014; 63:504-11. [DOI: 10.1097/fjc.0000000000000074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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O'Connell TD, Jensen BC, Baker AJ, Simpson PC. Cardiac alpha1-adrenergic receptors: novel aspects of expression, signaling mechanisms, physiologic function, and clinical importance. Pharmacol Rev 2013; 66:308-33. [PMID: 24368739 DOI: 10.1124/pr.112.007203] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate "inside-out" signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure.
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Affiliation(s)
- Timothy D O'Connell
- VA Medical Center (111-C-8), 4150 Clement St., San Francisco, CA 94121. ; or Dr. Timothy D. O'Connell, E-mail:
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Maloyan A, Muralimanoharan S, Huffman S, Cox LA, Nathanielsz PW, Myatt L, Nijland MJ. Identification and comparative analyses of myocardial miRNAs involved in the fetal response to maternal obesity. Physiol Genomics 2013; 45:889-900. [PMID: 23922128 DOI: 10.1152/physiolgenomics.00050.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Human and animal studies show that suboptimal intrauterine environments lead to fetal programming, predisposing offspring to disease in later life. Maternal obesity has been shown to program offspring for cardiovascular disease (CVD), diabetes, and obesity. MicroRNAs (miRNAs) are small, noncoding RNA molecules that act as key regulators of numerous cellular processes. Compelling evidence links miRNAs to the control of cardiac development and etiology of cardiac pathology; however, little is known about their role in the fetal cardiac response to maternal obesity. Our aim was to sequence and profile the cardiac miRNAs that are dysregulated in the hearts of baboon fetuses born to high fat/high fructose-diet (HFD) fed mothers for comparison with fetal hearts from mothers eating a regular diet. Eighty miRNAs were differentially expressed. Of those, 55 miRNAs were upregulated and 25 downregulated with HFD. Twenty-two miRNAs were mapped to human; 14 of these miRNAs were previously reported to be dysregulated in experimental or human CVD. We used an Ingenuity Pathway Analysis to integrate miRNA profiling and bioinformatics predictions to determine miRNA-regulated processes and genes potentially involved in fetal programming. We found a correlation between miRNA expression and putative gene targets involved in developmental disorders and CVD. Cellular death, growth, and proliferation were the most affected cellular functions in response to maternal obesity. Thus, the current study reveals significant alterations in cardiac miRNA expression in the fetus of obese baboons. The epigenetic modifications caused by adverse prenatal environment may represent one of the mechanisms underlying fetal programming of CVD.
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Affiliation(s)
- Alina Maloyan
- Center for Pregnancy and Newborn Research, Department of Obstetrics and Gynecology, University of Texas Health Science Center, San Antonio, Texas; and
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Bravo C, Kudej RK, Yuan C, Yoon S, Ge H, Park JY, Tian B, Stanley WC, Vatner SF, Vatner DE, Yan L. Metabolomic analysis of two different models of delayed preconditioning. J Mol Cell Cardiol 2012; 55:19-26. [PMID: 23127662 DOI: 10.1016/j.yjmcc.2012.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 10/13/2012] [Accepted: 10/14/2012] [Indexed: 01/17/2023]
Abstract
Recently we described an ischemic preconditioning induced by repetitive coronary stenosis, which is induced by 6 episodes of non-lethal ischemia over 3 days, and which also resembles the hibernating myocardium phenotype. When compared with traditional second window of ischemic preconditioning using cDNA microarrays, many genes which differed in the repetitive coronary stenosis appeared targeted to metabolism. Accordingly, the goal of this study was to provide a more in depth analysis of changes in metabolism in the different models of delayed preconditioning, i.e., second window and repetitive coronary stenosis. This was accomplished using a metabolomic approach based on liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) techniques. Myocardial samples from the ischemic section of porcine hearts subjected to both models of late preconditioning were compared against sham controls. Interestingly, although both models involve delayed preconditioning, their metabolic signatures were radically different; of the total number of metabolites that changed in both models (135 metabolites) only 7 changed in both models, and significantly more, p<0.01, were altered in the repetitive coronary stenosis (40%) than in the second window (8.1%). The most significant changes observed were in energy metabolism, e.g., phosphocreatine was increased 4 fold and creatine kinase activity increased by 27.2%, a pattern opposite from heart failure, suggesting that the repetitive coronary stenosis and potentially hibernating myocardium have enhanced stress resistance capabilities. The improved energy metabolism could also be a key mechanism contributing to the cardioprotection observed in the repetitive coronary stenosis and in hibernating myocardium. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism".
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Affiliation(s)
- Claudio Bravo
- Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ 07103, USA
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