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Maghsoudi S, Shuaib R, Van Bastelaere B, Dakshinamurti S. Adenylyl cyclase isoforms 5 and 6 in the cardiovascular system: complex regulation and divergent roles. Front Pharmacol 2024; 15:1370506. [PMID: 38633617 PMCID: PMC11021717 DOI: 10.3389/fphar.2024.1370506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/11/2024] [Indexed: 04/19/2024] Open
Abstract
Adenylyl cyclases (ACs) are crucial effector enzymes that transduce divergent signals from upstream receptor pathways and are responsible for catalyzing the conversion of ATP to cAMP. The ten AC isoforms are categorized into four main groups; the class III or calcium-inhibited family of ACs comprises AC5 and AC6. These enzymes are very closely related in structure and have a paucity of selective activators or inhibitors, making it difficult to distinguish them experimentally. AC5 and AC6 are highly expressed in the heart and vasculature, as well as the spinal cord and brain; AC6 is also abundant in the lungs, kidney, and liver. However, while AC5 and AC6 have similar expression patterns with some redundant functions, they have distinct physiological roles due to differing regulation and cAMP signaling compartmentation. AC5 is critical in cardiac and vascular function; AC6 is a key effector of vasodilatory pathways in vascular myocytes and is enriched in fetal/neonatal tissues. Expression of both AC5 and AC6 decreases in heart failure; however, AC5 disruption is cardio-protective, while overexpression of AC6 rescues cardiac function in cardiac injury. This is a comprehensive review of the complex regulation of AC5 and AC6 in the cardiovascular system, highlighting overexpression and knockout studies as well as transgenic models illuminating each enzyme and focusing on post-translational modifications that regulate their cellular localization and biological functions. We also describe pharmacological challenges in the design of isoform-selective activators or inhibitors for AC5 and AC6, which may be relevant to developing new therapeutic approaches for several cardiovascular diseases.
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Affiliation(s)
- Saeid Maghsoudi
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Rabia Shuaib
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Ben Van Bastelaere
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Shyamala Dakshinamurti
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
- Section of Neonatology, Department of Pediatrics, Health Sciences Centre, Winnipeg, MB, Canada
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Devasani K, Yao Y. Expression and functions of adenylyl cyclases in the CNS. Fluids Barriers CNS 2022; 19:23. [PMID: 35307032 PMCID: PMC8935726 DOI: 10.1186/s12987-022-00322-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/07/2022] [Indexed: 12/27/2022] Open
Abstract
Adenylyl cyclases (ADCYs), by generating second messenger cAMP, play important roles in various cellular processes. Their expression, regulation and functions in the CNS, however, remain largely unknown. In this review, we first introduce the classification and structure of ADCYs, followed by a discussion of the regulation of mammalian ADCYs (ADCY1-10). Next, the expression and function of each mammalian ADCY isoform are summarized in a region/cell-specific manner. Furthermore, the effects of GPCR-ADCY signaling on blood-brain barrier (BBB) integrity are reviewed. Last, current challenges and future directions are discussed. We aim to provide a succinct review on ADCYs to foster new research in the future.
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Affiliation(s)
- Karan Devasani
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, Tampa, FL, 33612, USA
| | - Yao Yao
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., MDC 8, Tampa, FL, 33612, USA.
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Ostrom KF, LaVigne JE, Brust TF, Seifert R, Dessauer CW, Watts VJ, Ostrom RS. Physiological Roles of Mammalian Transmembrane Adenylyl Cyclase Isoforms. Physiol Rev 2021; 102:815-857. [PMID: 34698552 DOI: 10.1152/physrev.00013.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Adenylyl cyclases (ACs) catalyze the conversion of ATP to the ubiquitous second messenger cAMP. Mammals possess nine isoforms of transmembrane ACs, dubbed AC1-9, that serve as major effector enzymes of G protein-coupled receptors. The transmembrane ACs display varying expression patterns across tissues, giving potential for them having a wide array of physiologic roles. Cells express multiple AC isoforms, implying that ACs have redundant functions. Furthermore, all transmembrane ACs are activated by Gαs so it was long assumed that all ACs are activated by Gαs-coupled GPCRs. AC isoforms partition to different microdomains of the plasma membrane and form prearranged signaling complexes with specific GPCRs that contribute to cAMP signaling compartments. This compartmentation allows for a diversity of cellular and physiological responses by enabling unique signaling events to be triggered by different pools of cAMP. Isoform specific pharmacological activators or inhibitors are lacking for most ACs, making knockdown and overexpression the primary tools for examining the physiological roles of a given isoform. Much progress has been made in understanding the physiological effects mediated through individual transmembrane ACs. GPCR-AC-cAMP signaling pathways play significant roles in regulating functions of every cell and tissue, so understanding each AC isoform's role holds potential for uncovering new approaches for treating a vast array of pathophysiological conditions.
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Affiliation(s)
- Katrina F Ostrom
- W. M. Keck Science Department, Claremont McKenna College, Claremont, CA, United States
| | - Justin E LaVigne
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States
| | - Tarsis F Brust
- Department of Pharmaceutical Sciences, Palm Beach Atlantic University, West Palm Beach, FL, United States
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas, United States
| | - Val J Watts
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, United States.,Purdue Institute for Drug Discovery, Purdue University, West Lafayette, IN, United States.,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Rennolds S Ostrom
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, United States
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Colombe AS, Pidoux G. Cardiac cAMP-PKA Signaling Compartmentalization in Myocardial Infarction. Cells 2021; 10:cells10040922. [PMID: 33923648 PMCID: PMC8073060 DOI: 10.3390/cells10040922] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023] Open
Abstract
Under physiological conditions, cAMP signaling plays a key role in the regulation of cardiac function. Activation of this intracellular signaling pathway mirrors cardiomyocyte adaptation to various extracellular stimuli. Extracellular ligand binding to seven-transmembrane receptors (also known as GPCRs) with G proteins and adenylyl cyclases (ACs) modulate the intracellular cAMP content. Subsequently, this second messenger triggers activation of specific intracellular downstream effectors that ensure a proper cellular response. Therefore, it is essential for the cell to keep the cAMP signaling highly regulated in space and time. The temporal regulation depends on the activity of ACs and phosphodiesterases. By scaffolding key components of the cAMP signaling machinery, A-kinase anchoring proteins (AKAPs) coordinate both the spatial and temporal regulation. Myocardial infarction is one of the major causes of death in industrialized countries and is characterized by a prolonged cardiac ischemia. This leads to irreversible cardiomyocyte death and impairs cardiac function. Regardless of its causes, a chronic activation of cardiac cAMP signaling is established to compensate this loss. While this adaptation is primarily beneficial for contractile function, it turns out, in the long run, to be deleterious. This review compiles current knowledge about cardiac cAMP compartmentalization under physiological conditions and post-myocardial infarction when it appears to be profoundly impaired.
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Cosson MV, Hiis HG, Moltzau LR, Levy FO, Krobert KA. Knockout of adenylyl cyclase isoform 5 or 6 differentially modifies the β 1-adrenoceptor-mediated inotropic response. J Mol Cell Cardiol 2019; 131:132-145. [PMID: 31009605 DOI: 10.1016/j.yjmcc.2019.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/15/2019] [Accepted: 04/17/2019] [Indexed: 12/15/2022]
Abstract
Although only β2-adrenergic receptors (βAR) dually couple with stimulatory G protein (Gs) and inhibitory G protein (Gi), inactivation of Gi enhances both β1AR and β2AR responsiveness. We hypothesize that Gi restrains spontaneous adenylyl cyclase (AC) activity independent of receptor activation. Subcellular localization of the AC5/6 subtypes varies contributing to the compartmentation of βAR signaling. The primary objectives were to determine: (1) if β1AR-mediated inotropic responses were dependent upon either AC5 or AC6; (2) if intrinsic Gi inhibition is AC subtype selective and (3) the role of phosphodiesterases (PDE) 3/4 to regulate β1AR responsiveness. β1AR-mediated increases in contractile force and cAMP accumulation in cardiomyocytes were measured from wild type, AC5 and AC6 knockout (KO) mice, with or without pertussis toxin (PTX) pretreatment to inactivate Gi and/or after selective inhibition of PDEs 3/4. Noradrenaline potency at β1ARs was increased in AC6 KO. PDE4 inhibition increased noradrenaline potency in wild type and AC5 KO, but not AC6 KO. PTX increased noradrenaline potency only in wild type but increased the maximal β1AR response in all mouse strains. PDE3 inhibition increased noradrenaline potency only in AC5 KO that was treated prior with PTX. β1AR-evoked cAMP accumulation was increased more by PDE4 inhibition than PDE3 inhibition in wild type and AC5 KO that was amplified by Gi inhibition. These data indicate that β1AR-mediated inotropic responses are not dependent upon either AC5 or AC6 alone. Inactivation of Gi enhanced β1AR-mediated inotropic responses despite not coupling to Gi, consistent with Gi exerting a tonic receptor independent inhibition upon AC5/6. PDE4 seems the primary regulator of β1AR signaling through AC6 in wild type. AC6 KO results in a reorganization of β1AR compartmentation characterized by signaling through AC5 regulated by Gi, PDE3 and PDE4 that maintains normal contractile function.
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Affiliation(s)
- Marie-Victoire Cosson
- Department of Pharmacology and Center for Heart Failure Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Halvard Gautefall Hiis
- Department of Pharmacology and Center for Heart Failure Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Lise Román Moltzau
- Department of Pharmacology and Center for Heart Failure Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Finn Olav Levy
- Department of Pharmacology and Center for Heart Failure Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.
| | - Kurt Allen Krobert
- Department of Pharmacology and Center for Heart Failure Research, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway
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Leroy J, Vandecasteele G, Fischmeister R. Cyclic AMP signaling in cardiac myocytes. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2017.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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7
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Function of Adenylyl Cyclase in Heart: the AKAP Connection. J Cardiovasc Dev Dis 2018; 5:jcdd5010002. [PMID: 29367580 PMCID: PMC5872350 DOI: 10.3390/jcdd5010002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/09/2018] [Accepted: 01/11/2018] [Indexed: 12/13/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP), synthesized by adenylyl cyclase (AC), is a universal second messenger that regulates various aspects of cardiac physiology from contraction rate to the initiation of cardioprotective stress response pathways. Local pools of cAMP are maintained by macromolecular complexes formed by A-kinase anchoring proteins (AKAPs). AKAPs facilitate control by bringing together regulators of the cAMP pathway including G-protein-coupled receptors, ACs, and downstream effectors of cAMP to finely tune signaling. This review will summarize the distinct roles of AC isoforms in cardiac function and how interactions with AKAPs facilitate AC function, highlighting newly appreciated roles for lesser abundant AC isoforms.
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Dessauer CW, Watts VJ, Ostrom RS, Conti M, Dove S, Seifert R. International Union of Basic and Clinical Pharmacology. CI. Structures and Small Molecule Modulators of Mammalian Adenylyl Cyclases. Pharmacol Rev 2017; 69:93-139. [PMID: 28255005 PMCID: PMC5394921 DOI: 10.1124/pr.116.013078] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adenylyl cyclases (ACs) generate the second messenger cAMP from ATP. Mammalian cells express nine transmembrane AC (mAC) isoforms (AC1-9) and a soluble AC (sAC, also referred to as AC10). This review will largely focus on mACs. mACs are activated by the G-protein Gαs and regulated by multiple mechanisms. mACs are differentially expressed in tissues and regulate numerous and diverse cell functions. mACs localize in distinct membrane compartments and form signaling complexes. sAC is activated by bicarbonate with physiologic roles first described in testis. Crystal structures of the catalytic core of a hybrid mAC and sAC are available. These structures provide detailed insights into the catalytic mechanism and constitute the basis for the development of isoform-selective activators and inhibitors. Although potent competitive and noncompetitive mAC inhibitors are available, it is challenging to obtain compounds with high isoform selectivity due to the conservation of the catalytic core. Accordingly, caution must be exerted with the interpretation of intact-cell studies. The development of isoform-selective activators, the plant diterpene forskolin being the starting compound, has been equally challenging. There is no known endogenous ligand for the forskolin binding site. Recently, development of selective sAC inhibitors was reported. An emerging field is the association of AC gene polymorphisms with human diseases. For example, mutations in the AC5 gene (ADCY5) cause hyperkinetic extrapyramidal motor disorders. Overall, in contrast to the guanylyl cyclase field, our understanding of the (patho)physiology of AC isoforms and the development of clinically useful drugs targeting ACs is still in its infancy.
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Affiliation(s)
- Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Val J Watts
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Rennolds S Ostrom
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Marco Conti
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Stefan Dove
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Roland Seifert
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
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9
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Boularan C, Gales C. Cardiac cAMP: production, hydrolysis, modulation and detection. Front Pharmacol 2015; 6:203. [PMID: 26483685 PMCID: PMC4589651 DOI: 10.3389/fphar.2015.00203] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/03/2015] [Indexed: 01/04/2023] Open
Abstract
Cyclic adenosine 3′,5′-monophosphate (cAMP) modulates a broad range of biological processes including the regulation of cardiac myocyte contractile function where it constitutes the main second messenger for β-adrenergic receptors' signaling to fulfill positive chronotropic, inotropic and lusitropic effects. A growing number of studies pinpoint the role of spatial organization of the cAMP signaling as an essential mechanism to regulate cAMP outcomes in cardiac physiology. Here, we will briefly discuss the complexity of cAMP synthesis and degradation in the cardiac context, describe the way to detect it and review the main pharmacological arsenal to modulate its availability.
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Affiliation(s)
- Cédric Boularan
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université Toulouse III Paul Sabatier Toulouse, France
| | - Céline Gales
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université Toulouse III Paul Sabatier Toulouse, France
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10
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Heinick A, Husser X, Himmler K, Kirchhefer U, Nunes F, Schulte JS, Seidl MD, Rolfes C, Dedman JR, Kaetzel MA, Gerke V, Schmitz W, Müller FU. Annexin A4 is a novel direct regulator of adenylyl cyclase type 5. FASEB J 2015; 29:3773-87. [PMID: 26023182 DOI: 10.1096/fj.14-269837] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/12/2015] [Indexed: 12/14/2022]
Abstract
Annexin A4 (AnxA4), a Ca(2+)- and phospholipid-binding protein, is up-regulated in the human failing heart. In this study, we examined the impact of AnxA4 on β-adrenoceptor (β-AR)/cAMP-dependent signal transduction. Expression of murine AnxA4 in human embryonic kidney (HEK)293 cells dose-dependently inhibited cAMP levels after direct stimulation of adenylyl cyclases (ACs) with forskolin (FSK), as determined with an exchange protein activated by cAMP-Förster resonance energy transfer (EPAC-FRET) sensor and an ELISA (control vs. +AnxA4: 1956 ± 162 vs. 1304 ± 185 fmol/µg protein; n = 8). Disruption of the anxA4 gene led to a consistent increase in intracellular cAMP levels in isolated adult mouse cardiomyocytes, with heart-directed expression of the EPAC-FRET sensor, stimulated with FSK, and as determined by ELISA, also in mouse cardiomyocytes stimulated with the β-AR agonist isoproterenol (ISO) (anxA4a(+/+) vs. anxA4a(-/-): 5.1 ± 0.3 vs. 6.7 ± 0.6 fmol/µg protein) or FSK (anxA4a(+/+) vs. anxA4a(-/-): 1891 ± 238 vs. 2796 ± 343 fmol/µg protein; n = 9-10). Coimmunoprecipitation experiments in HEK293 cells revealed a direct interaction of murine AnxA4 with human membrane-bound AC type 5 (AC5). As a functional consequence of AnxA4-mediated AC inhibition, AnxA4 inhibited the FSK-induced transcriptional activation mediated by the cAMP response element (CRE) in reporter gene studies (10-fold vs. control; n = 4 transfections) and reduced the FSK-induced phosphorylation of the CRE-binding protein (CREB) measured on Western blots (control vs. +AnxA4: 150 ± 17% vs. 105 ± 10%; n = 6) and by the use of the indicator of CREB activation caused by phosphorylation (ICAP)-FRET sensor, indicating CREB phosphorylation. Inactivation of AnxA4 in anxA4a(-/-) mice was associated with an increased cardiac response to β-AR stimulation. Together, these results suggest that AnxA4 is a novel direct negative regulator of AC5, adding a new facet to the functions of annexins.
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Affiliation(s)
- Alexander Heinick
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Xenia Husser
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Kirsten Himmler
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Uwe Kirchhefer
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Frank Nunes
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Jan S Schulte
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Matthias D Seidl
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Christina Rolfes
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - John R Dedman
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Marcia A Kaetzel
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Volker Gerke
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Wilhelm Schmitz
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Frank U Müller
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
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11
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Cyclic AMP synthesis and hydrolysis in the normal and failing heart. Pflugers Arch 2014; 466:1163-75. [PMID: 24756197 DOI: 10.1007/s00424-014-1515-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 12/12/2022]
Abstract
Cyclic AMP regulates a multitude of cellular responses and orchestrates a network of intracellular events. In the heart, cAMP is the main second messenger of the β-adrenergic receptor (β-AR) pathway producing positive chronotropic, inotropic, and lusitropic effects during sympathetic stimulation. Whereas short-term stimulation of β-AR/cAMP is beneficial for the heart, chronic activation of this pathway triggers pathological cardiac remodeling, which may ultimately lead to heart failure (HF). Cyclic AMP is controlled by two families of enzymes with opposite actions: adenylyl cyclases, which control cAMP production and phosphodiesterases, which control its degradation. The large number of families and isoforms of these enzymes, their different localization within the cell, and their organization in macromolecular complexes leads to a high level of compartmentation, both in space and time, of cAMP signaling in cardiac myocytes. Here, we review the expression level, molecular characteristics, functional properties, and roles of the different adenylyl cyclase and phosphodiesterase families expressed in heart muscle and the changes that occur in cardiac hypertrophy and failure.
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12
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Okumura S, Fujita T, Cai W, Jin M, Namekata I, Mototani Y, Jin H, Ohnuki Y, Tsuneoka Y, Kurotani R, Suita K, Kawakami Y, Hamaguchi S, Abe T, Kiyonari H, Tsunematsu T, Bai Y, Suzuki S, Hidaka Y, Umemura M, Ichikawa Y, Yokoyama U, Sato M, Ishikawa F, Izumi-Nakaseko H, Adachi-Akahane S, Tanaka H, Ishikawa Y. Epac1-dependent phospholamban phosphorylation mediates the cardiac response to stresses. J Clin Invest 2014; 124:2785-801. [PMID: 24892712 DOI: 10.1172/jci64784] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PKA phosphorylates multiple molecules involved in calcium (Ca2+) handling in cardiac myocytes and is considered to be the predominant regulator of β-adrenergic receptor-mediated enhancement of cardiac contractility; however, recent identification of exchange protein activated by cAMP (EPAC), which is independently activated by cAMP, has challenged this paradigm. Mice lacking Epac1 (Epac1 KO) exhibited decreased cardiac contractility with reduced phospholamban (PLN) phosphorylation at serine-16, the major PKA-mediated phosphorylation site. In Epac1 KO mice, intracellular Ca2+ storage and the magnitude of Ca2+ movement were decreased; however, PKA expression remained unchanged, and activation of PKA with isoproterenol improved cardiac contractility. In contrast, direct activation of EPAC in cardiomyocytes led to increased PLN phosphorylation at serine-16, which was dependent on PLC and PKCε. Importantly, Epac1 deletion protected the heart from various stresses, while Epac2 deletion was not protective. Compared with WT mice, aortic banding induced a similar degree of cardiac hypertrophy in Epac1 KO; however, lack of Epac1 prevented subsequent cardiac dysfunction as a result of decreased cardiac myocyte apoptosis and fibrosis. Similarly, Epac1 KO animals showed resistance to isoproterenol- and aging-induced cardiomyopathy and attenuation of arrhythmogenic activity. These data support Epac1 as an important regulator of PKA-independent PLN phosphorylation and indicate that Epac1 regulates cardiac responsiveness to various stresses.
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Braeunig JH, Schweda F, Han PL, Seifert R. Similarly potent inhibition of adenylyl cyclase by P-site inhibitors in hearts from wild type and AC5 knockout mice. PLoS One 2013; 8:e68009. [PMID: 23840883 PMCID: PMC3698094 DOI: 10.1371/journal.pone.0068009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 05/24/2013] [Indexed: 01/26/2023] Open
Abstract
Adenylyl cyclase type 5 (AC5) was described as major cardiac AC isoform. The knockout of AC5 (AC5KO) exerted cardioprotective effects in heart failure. Our study explored the impact of AC5KO on mouse heart AC activities and evaluated putative AC5-selective inhibitors. In cardiac membranes from AC5KO mice, basal AC activity was decreased, while AC stimulation was intact. The putative AC5-selective P-site inhibitors SQ22,536 [9-(tetra-hydro-2-furanyl)-9H-purin-6-amine], vidarabine (9-β-D-arabinosyladenine) and NKY80 [2-amino-7-(2-furanyl)-7,8-dihydro-5(6H)-quinazolinone] inhibited recombinant AC5 more potently than AC2 and AC1, but selectivity was only modest (∼4-40-fold). These compounds inhibited cardiac AC from WT and AC5KO mice with similar potencies. In conclusion, AC regulation in AC5KO hearts was unimpaired, questioning the supposed dominant role of AC5 in the heart. Moreover, the AC inhibitors SQ22,536, NKY80 and vidarabine lack adequate selectivity for AC5 and, therefore, do not present suitable tools to study AC5-specific functions.
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Affiliation(s)
- Joerg H. Braeunig
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Pyung-Lim Han
- Department of Brain and Cognitive Science, Graduate School, Ewha Woman University, Seoul, Korea
| | - Roland Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
- * E-mail:
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14
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Bai Y, Tsunematsu T, Jiao Q, Ohnuki Y, Mototani Y, Shiozawa K, Jin M, Cai W, Jin HL, Fujita T, Ichikawa Y, Suita K, Kurotani R, Yokoyama U, Sato M, Iwatsubo K, Ishikawa Y, Okumura S. Pharmacological stimulation of type 5 adenylyl cyclase stabilizes heart rate under both microgravity and hypergravity induced by parabolic flight. J Pharmacol Sci 2012; 119:381-9. [PMID: 22850613 DOI: 10.1254/jphs.12102fp] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
We previously demonstrated that type 5 adenylyl cyclase (AC5) functions in autonomic regulation in the heart. Based on that work, we hypothesized that pharmacological modulation of AC5 activity could regulate the autonomic control of the heart rate under micro- and hypergravity. To test this hypothesis, we selected the approach of activating AC5 activity in mice with a selective AC5 activator (NKH477) or inhibitor (vidarabine) and examining heart rate variability during parabolic flight. The standard deviation of normal R-R intervals, a marker of total autonomic variability, was significantly greater under micro- and hypergravity in the vidarabine group, while there were no significant changes in the NKH477 group, suggesting that autonomic regulation was unstable in the vidarabine group. The ratio of low frequency and high frequency (HF) in heart rate variability analysis, a marker of sympathetic activity, became significantly decreased under micro- and hypergravity in the NKH477 group, while there was no such decrease in the vidarabine group. Normalized HF, a marker of parasympathetic activity, became significantly greater under micro- and hypergravity in the NKH477 group. In contrast, there was no such increase in the vidarabine group. This study is the first to indicate that pharmacological modulation of AC5 activity under micro- and hypergravity could be useful to regulate the autonomic control of the heart rate.
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Affiliation(s)
- Yunzhe Bai
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Japan
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15
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Abstract
Congestive heart failure is an inexorable disease associated with unacceptably high morbidity and mortality. Preclinical results indicate that gene transfer using various proteins is a safe and effective approach for increasing function of the failing heart. In the current review, we provide a summary of cardiac gene transfer in general and summarize findings using adenylyl cyclase 6 as therapeutic gene in the failing heart. We also discuss the potential usefulness of a new treatment for congestive heart failure, paracrine-based gene transfer.
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Affiliation(s)
- T Tang
- Department of Medicine, University of California San Diego, CA, USA
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16
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Tang T, Hammond HK, Firth A, Yang Y, Gao MH, Yuan JXJ, Lai NC. Adenylyl cyclase 6 improves calcium uptake and left ventricular function in aged hearts. J Am Coll Cardiol 2011; 57:1846-55. [PMID: 21527160 DOI: 10.1016/j.jacc.2010.11.052] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 11/09/2010] [Accepted: 11/09/2010] [Indexed: 01/08/2023]
Abstract
OBJECTIVES This study tested the hypothesis that activation of adenylyl cyclase 6 (AC6) expression in cardiac myocytes improves calcium uptake and left ventricular (LV) function in aging mice. BACKGROUND Aging hearts exhibit impaired β-adrenergic receptor signaling and LV dysfunction. METHODS Twenty-month-old mice with cardiac-directed and regulated AC6 expression were randomized into 2 groups, and AC6 expression was activated in 1 group (AC6-On) but not the other (AC6-Off). One month later, LV function and sarcoplasmic reticulum calcium uptake were assessed. RESULTS AC6 expression was associated with increased LV contractility, as reflected by ejection fraction (p = 0.02), rate of pressure development (p = 0.002), and slope of the LV end-systolic pressure-volume relationship (p = 0.04). No changes in LV weight to tibial length ratio, LV fibrosis, and expression of fetal genes (atrial natriuretic factor, α-skeletal muscle actin, and β-myosin heavy chain) and collagens were observed between AC6-On and AC6-Off groups. However, LV samples from AC6-On mice showed increases in: isoproterenol-stimulated cAMP production (p = 0.04), cAMP-dependent protein kinase activity (p < 0.0004), phosphorylation of phospholamban (at Ser16 site; p = 0.04) and cardiac troponin I (at Ser23/24 sites; p = 0.01), velocity of sarcoplasmic reticulum calcium uptake (p < 0.0001), and sarcoplasmic reticulum calcium-ATPase2a (SERCA2a) affinity for calcium (p < 0.0001). Finally, we found that AC6 expression increased sarcoplasmic reticulum calcium storage in cardiac myocytes isolated from 23-month-old rats. In contrast, AC6 expression in 7-month-old mice did not change LV function and calcium uptake. CONCLUSIONS These results indicate that activation of cardiac AC6 expression improves impaired function of aged hearts through improved calcium uptake.
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Affiliation(s)
- Tong Tang
- VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
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17
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Gao MH, Hammond HK. Unanticipated signaling events associated with cardiac adenylyl cyclase gene transfer. J Mol Cell Cardiol 2011; 50:751-8. [PMID: 21354173 DOI: 10.1016/j.yjmcc.2011.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Revised: 02/04/2011] [Accepted: 02/07/2011] [Indexed: 12/31/2022]
Abstract
The published papers on the effects of increased cardiac expression of adenylyl cyclase type 6 (AC6) are reviewed. These include the effects of AC on normal and failing left ventricle in several pathophysiological models in mice and pigs. In addition, the effects of increased expression of AC6 in cultured neonatal and adult rat cardiac myocytes are discussed in the context of attempting to establish mechanisms for the unanticipated beneficial effects of AC6 on the failing heart. This article is part of a Special Section entitled "Special Section: Cardiovascular Gene Therapy".
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Affiliation(s)
- Mei Hua Gao
- VA San Diego Healtcare System and University of California San Diego, San Diego, CA, USA
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18
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Timofeyev V, Porter CA, Tuteja D, Qiu H, Li N, Tang T, Singapuri A, Han PL, Lopez JE, Hammond HK, Chiamvimonvat N. Disruption of adenylyl cyclase type V does not rescue the phenotype of cardiac-specific overexpression of Galphaq protein-induced cardiomyopathy. Am J Physiol Heart Circ Physiol 2010; 299:H1459-67. [PMID: 20709863 DOI: 10.1152/ajpheart.01208.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Adenylyl cyclase (AC) is the principal effector molecule in the β-adrenergic receptor pathway. AC(V) and AC(VI) are the two predominant isoforms in mammalian cardiac myocytes. The disparate roles among AC isoforms in cardiac hypertrophy and progression to heart failure have been under intense investigation. Specifically, the salutary effects resulting from the disruption of AC(V) have been established in multiple models of cardiomyopathy. It has been proposed that a continual activation of AC(V) through elevated levels of protein kinase C could play an integral role in mediating a hypertrophic response leading to progressive heart failure. Elevated protein kinase C is a common finding in heart failure and was demonstrated in murine cardiomyopathy from cardiac-specific overexpression of G(αq) protein. Here we assessed whether the disruption of AC(V) expression can improve cardiac function, limit electrophysiological remodeling, or improve survival in the G(αq) mouse model of heart failure. We directly tested the effects of gene-targeted disruption of AC(V) in transgenic mice with cardiac-specific overexpression of G(αq) protein using multiple techniques to assess the survival, cardiac function, as well as structural and electrical remodeling. Surprisingly, in contrast to other models of cardiomyopathy, AC(V) disruption did not improve survival or cardiac function, limit cardiac chamber dilation, halt hypertrophy, or prevent electrical remodeling in G(αq) transgenic mice. In conclusion, unlike other established models of cardiomyopathy, disrupting AC(V) expression in the G(αq) mouse model is insufficient to overcome several parallel pathophysiological processes leading to progressive heart failure.
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Affiliation(s)
- Valeriy Timofeyev
- Division of Cardiovascular Medicine, University of California, Davis, California 95616, USA
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19
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Pierre S, Eschenhagen T, Geisslinger G, Scholich K. Capturing adenylyl cyclases as potential drug targets. Nat Rev Drug Discov 2009; 8:321-35. [PMID: 19337273 DOI: 10.1038/nrd2827] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cyclic AMP (cAMP) is an important intracellular signalling mediator. It is generated in mammals by nine membrane-bound and one soluble adenylyl cyclases (ACs), each with distinct regulation and expression patterns. Although many drugs inhibit or stimulate AC activity through the respective upstream G-protein coupled receptors (for example, opioid or beta-adrenergic receptors), ACs themselves have not been major drug targets. Over the past decade studies on the physiological functions of the different mammalian AC isoforms as well as advances in the development of isoform-selective AC inhibitors and activators suggest that ACs could be useful drug targets. Here we discuss the therapeutic potential of isoform-selective compounds in various clinical settings, including neuropathic pain, neurodegenerative disorders, congestive heart failure, asthma and male contraception.
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Affiliation(s)
- Sandra Pierre
- Pharmazentrum Frankfurt, ZAFES, Institut für Klinische Pharmakologie, Klinikum der Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
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20
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Hünlich M, Hasenfuss G. Effects of the NO donor sodium nitroprusside on oxygen consumption and energetics in rabbit myocardium. Basic Res Cardiol 2009; 104:359-65. [PMID: 19190952 PMCID: PMC3085761 DOI: 10.1007/s00395-009-0777-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Accepted: 12/22/2008] [Indexed: 12/05/2022]
Abstract
Nitric oxide (NO) has influence on various cellular functions. Little is known of the influence of NO on myocardial energetics. In the present study oxygen consumption and mechanical parameters of isometrically contracting rabbit papillary muscles (1 Hz stimulation frequency) were investigated at varying interventions while maintaining physiological conditions (37°C; 2.5 mM Ca2+) to study the effects of NO on energetics. The NO donor sodium nitroprusside (SNP) showed a negative inotropic effect. SNP decreased the maximal force in normal rabbit muscle strips by 30%, the force time integral (FTI) by 40% and the relaxation time by 20%. In addition the oxygen consumption decreased by 60%, a notably disproportional decrease compared to the mechanical parameters. Consequently, the economy as a ratio of FTI and oxygen consumption is significantly increased by SNP. In contrast the negative inotropic effect due to a reduction in extracellular Calcium (Ca2+) from 2.5 to 1.25 mM reduced FTI and oxygen consumption proportionally by 40% and did not change economy. The effect of NO on force and oxygen consumption could be reproduced by the application of the cyclic guanosine monophosphate (cGMP) analogue 8-bromo-cGMP. In summary, NO increased the economy of isometrically contracting papillary muscles. The improvement in contraction economy under NO seems to be mediated by cGMP as the secondary messenger and maybe due to alterations of the crossbridge cycle.
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Affiliation(s)
- Mark Hünlich
- Universitätsklinik Göttingen, Abteilung für Kardiologie, Robert-Koch-Strasse 40, 37099, Göttingen, Germany.
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21
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Gross DR. Other Transgenic Animal Models Used in Cardiovascular Studies. ANIMAL MODELS IN CARDIOVASCULAR RESEARCH 2009. [PMCID: PMC7121723 DOI: 10.1007/978-0-387-95962-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Previous chapters have described a large number of transgenic animal models used to study specific cardiovascular syndromes. This chapter will fill in some gaps. Many of these transgenic animals were developed to study normal and/or abnormal physiological responses in other organ systems, or to study basic biochemical and molecular reactions or pathways. These models were then discovered to also have effects on the cardiovascular system, some of them unanticipated. A word of caution, particularly when highly inbred mouse strains are used to develop transgenic models - not all strains of a particular species are created equal. When cardiovascular parameters of age- and sex-matched A/J and C57BL/6J inbred mice were compared the C57BL/6J mice demonstrated eccentric physiologic ventricular hypertrophy, increased ventricular function, lower heart rates, and increased exercise endurance.1
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22
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Sadana R, Dessauer CW. Physiological roles for G protein-regulated adenylyl cyclase isoforms: insights from knockout and overexpression studies. Neurosignals 2008; 17:5-22. [PMID: 18948702 DOI: 10.1159/000166277] [Citation(s) in RCA: 257] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 04/22/2008] [Indexed: 01/08/2023] Open
Abstract
Cyclic AMP is a universal second messenger, produced by a family of adenylyl cyclase (AC) enzymes. The last three decades have brought a wealth of new information about the regulation of cyclic AMP production by ACs. Nine hormone-sensitive, membrane-bound AC isoforms have been identified in addition to a tenth isoform that lacks membrane spans and more closely resembles the cyanobacterial AC enzymes. New model systems for purifying and characterizing the catalytic domains of AC have led to the crystal structure of these domains and the mapping of numerous interaction sites. However, big hurdles remain in unraveling the roles of individual AC isoforms and their regulation in physiological systems. In this review we explore the latest on AC knockout and overexpression studies to better understand the roles of G protein regulation of ACs in the brain, olfactory bulb, and heart.
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Affiliation(s)
- Rachna Sadana
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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23
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Rajagopalan V, Zucker IH, Jones JA, Carlson M, Ma YJ. Cardiac ErbB-1/ErbB-2 mutant expression in young adult mice leads to cardiac dysfunction. Am J Physiol Heart Circ Physiol 2008; 295:H543-54. [DOI: 10.1152/ajpheart.91436.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Multiple factors lead to the development and maintenance of chronic heart failure. Blockade of ErbB-2 or ErbB-4 tyrosine kinase receptor signaling leads to dilated cardiomyopathy. ErbB-1 may protect the heart against stress-induced injury and its ligand; epidermal growth factor (EGF) increases myocardial contractility, whereas heparin-binding EGF is essential for normal cardiac function. However, the role of ErbB-1 in control of cardiac function is not clear. We hypothesized that ErbB-1 is essential for maintaining adult cardiac function. Using the ecdysone-inducible gene expression system, we expressed humanized cardiomyocyte-specific dominant-negative ErbB-1 mutant receptors (hErbB-1-mut) in young adult mice that block endogenous cardiac ErbB-1 signaling. Molecular, morphological, and physiological tests (under anesthesia) were performed. As a result, hErbB-1-mut was expressed selectively in cardiomyocytes leading to the blockade of endogenous ErbB-1 phosphorylation and ErbB-2 transphosphorylation. An increase in left ventricular mass, atrial natriuretic factor expression, and histological changes were indicative of cardiac hypertrophy. Cardiac dilation, numerous cardiac lesions, and the loss of the clear boundary between cardiac fibrils were noted histologically. Early and long-term hErbB-1-mut induction led to a significant decrease in fractional shortening and to significant increases in left ventricular end-systolic diameter and volume. The treatment of adenylyl cyclase activator (forskolin analog) normalized the depressed cardiac function. Resting cardiac function returned to normal after reversing mutant expression. A 4-day survival rate of transverse-aortic constricted hErbB-1-mut mice was only 20% compared with 100% in controls. In conclusion, these observations indicate that the blockade of cardiac ErbB-1 signaling leads to the blockade of ErbB-2 signaling and that together they result in cardiac dysfunction.
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24
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Okumura S, Tsunematsu T, Bai Y, Jiao Q, Ono S, Suzuki S, Kurotani R, Sato M, Minamisawa S, Umemura S, Ishikawa Y. Type 5 adenylyl cyclase plays a major role in stabilizing heart rate in response to microgravity induced by parabolic flight. J Appl Physiol (1985) 2008; 105:173-9. [PMID: 18450980 DOI: 10.1152/japplphysiol.01166.2007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is well known that autonomic nervous activity is altered under microgravity, leading to disturbed regulation of cardiac function, such as heart rate. Autonomic regulation of the heart is mostly determined by beta-adrenergic receptors/cAMP signal, which is produced by adenylyl cyclase, in cardiac myocytes. To examine a hypothesis that a major cardiac isoform, type 5 adenylyl cyclase (AC5), plays an important role in regulating heart rate during parabolic flights, we used transgenic mouse models with either disrupted (AC5KO) or overexpressed AC5 in the heart (AC5TG) and analyzed heart rate variability. Heart rate had a tendency to decrease gradually in later phases within one parabola in each genotype group, but the magnitude of decrease was smaller in AC5KO than that in the other groups. The inverse of heart rate, i.e., the R-R interval, was much more variable in AC5KO and less variable in AC5TG than that in wild-type controls. The standard deviation of normal R-R intervals, a marker of total autonomic variability, was significantly greater in microgravity phase in each genotype group, but the magnitude of increase was much greater in AC5KO than that in the other groups, suggesting that heart rate regulation became unstable in the absence of AC5. In all, AC5 plays a major role in stabilizing heat rate under microgravity.
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Affiliation(s)
- Satoshi Okumura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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25
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Phan HM, Gao MH, Lai NC, Tang T, Hammond HK. New signaling pathways associated with increased cardiac adenylyl cyclase 6 expression: implications for possible congestive heart failure therapy. Trends Cardiovasc Med 2008; 17:215-21. [PMID: 17936202 DOI: 10.1016/j.tcm.2007.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 07/30/2007] [Accepted: 07/31/2007] [Indexed: 01/08/2023]
Abstract
Congestive heart failure (CHF) affects more than five million people in the United States and results in considerable morbidity, mortality, and economic costs. Patients with class III and IV CHF have a 40% to 50% probability of dying 5 years after symptom onset despite optimal therapy, a prognosis worse than many cancers. A variety of drugs and devices have improved survival-the 50% survival time in 1980 was just 18 months-but the outlook for patients remains dismal and the prevalence of CHF continues to increase. This unmet medical need underscores the importance of developing new approaches for the treatment of CHF. This brief review focuses on data from preclinical experiments regarding the effects of increased adenylyl cyclase type 6 (AC6) expression on cellular and cardiac function, and possible mechanisms for the unexpected favorable effects of increased AC6 content on the failing heart.
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Affiliation(s)
- Huy M Phan
- Department of Medicine, University of California at San Diego, CA 92093, USA
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26
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Tang T, Gao MH, Lai NC, Firth AL, Takahashi T, Guo T, Yuan JXJ, Roth DM, Hammond HK. Adenylyl cyclase type 6 deletion decreases left ventricular function via impaired calcium handling. Circulation 2007; 117:61-9. [PMID: 18071070 DOI: 10.1161/circulationaha.107.730069] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Adenylyl cyclases (ACs) are a family of effector molecules for G-protein-coupled receptors. The 2 ACs most abundantly expressed in cardiac myocytes are types 5 (AC5) and 6 (AC6), which have 65% amino acid homology. It has been speculated that coexpression of 2 AC types in cardiac myocytes represents redundancy, but the specific role of AC6 in cardiac physiology and its differences from AC5 remain to be defined. METHODS AND RESULTS We generated transgenic mice with targeted deletion of AC6. Deletion of AC6 was associated with reduced left ventricular contractile function (P=0.026) and relaxation (P=0.041). The absence of AC6 was associated with a 48% decay in beta-adrenergic receptor-stimulated cAMP production in cardiac myocytes (P=0.003) and reduced protein kinase A activity (P=0.015). In addition, phospholamban phosphorylation was reduced (P=0.015), sarcoplasmic reticulum Ca2+-ATPase activity was impaired (P<0.0001), and cardiac myocytes showed marked abnormalities in calcium transient formation (P=0.001). CONCLUSIONS The combination of impaired cardiac cAMP generation and calcium handling that result from AC6 deletion underlies abnormalities in left ventricular function. The biochemical and physiological consequences of AC6 deletion reveal it to be an important effector molecule in the adult heart, serving unique biological functions not replicated by AC5.
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Affiliation(s)
- Tong Tang
- Department of Medicine, University of California, San Diego, USA
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27
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Esposito G, Perrino C, Ozaki T, Takaoka H, Defer N, Petretta MP, De Angelis MC, Mao L, Hanoune J, Rockman HA, Chiariello M. Increased myocardial contractility and enhanced exercise function in transgenic mice overexpressing either adenylyl cyclase 5 or 8. Basic Res Cardiol 2007; 103:22-30. [PMID: 18034275 DOI: 10.1007/s00395-007-0688-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Accepted: 10/22/2007] [Indexed: 01/08/2023]
Abstract
OBJECTIVE ss-adrenergic receptors (ssARs) are powerful regulators of cardiac function in vivo, activating heterotrimeric G proteins and the effector molecule adenylyl cyclase (AC). Interestingly, cardiac-specific overexpression of different AC isoforms leads to variable changes in cardiac function. Whether AC overexpression affects intrinsic cardiac contractility in an isoform-specific fashion determining a change in exercise capacity is currently unknown. METHODS To address this issue, we performed load-independent measurements of cardiac systolic and diastolic function by pressure-volume (PV) loop analysis in intact wild-type mice (WT) and transgenic mice overexpressing the AC isoforms 5 or 8. RESULTS Here we show that cardiac overexpression of either AC5 or AC8 transgenic mice determined an increase in intrinsic cardiac contractility. Interestingly, AC8 transgenic mice displayed a significantly greater increase in cardiac contractility and improved active phase of relaxation. Despite these differences detected by PV loop analysis, both AC5 and AC8 mice showed a marked increase in exercise capacity on treadmill testing. CONCLUSIONS Our results demonstrate that load-independent measurements of cardiac function are needed to compare different groups of genetically-modified mouse models and to detect subtle AC isoform-specific changes in cardiac performance.
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Affiliation(s)
- Giovanni Esposito
- Division of Cardiology, University Federico II of Naples, Via Pansini 5, 80131 Naples, Italy.
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Chester JA, Watts VJ. Adenylyl Cyclase 5: A New Clue in the Search for the "Fountain of Youth"? ACTA ACUST UNITED AC 2007; 2007:pe64. [PMID: 18029912 DOI: 10.1126/stke.4132007pe64] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Julia A Chester
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47907, USA
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Abstract
Myocardial protection aims at preventing myocardial tissue loss: (a) In the acute stage, i.e., during primary angioplasty in acute myocardial infarction. In this setup, the attenuation of reperfusion injury is the main target. As a "mechanical" means, post-conditioning has already been tried in man with encouraging results. Pharmacologic interventions that could be of promise are statins, insulin, peptide hormones, including erythropoietin, fibroblast growth factor, and many others. (b) The patient with chronic coronary artery disease offers another paradigm, with the target of avoidance of further myocyte loss through apoptosis and inflammation. Various pharmacologic agents may prove useful in this context, together with exercise and "mechanical" improvement of cardiac function with attenuation of myocardial stretch, which by itself is a noxious influence. A continuous effort toward acute and chronically preserving myocardial integrity is a concept concerning both the researcher and the clinician.
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Affiliation(s)
- Dennis V Cokkinos
- 1st Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece.
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