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Li X, Li J, Samuelsson AM, Thakur H, Kapiloff MS. Protein phosphatase 2A anchoring disruptor gene therapy for familial dilated cardiomyopathy. Mol Ther Methods Clin Dev 2024; 32:101233. [PMID: 38572067 PMCID: PMC10988123 DOI: 10.1016/j.omtm.2024.101233] [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: 11/06/2023] [Accepted: 03/08/2024] [Indexed: 04/05/2024]
Abstract
Familial dilated cardiomyopathy is a prevalent cause of heart failure that results from the mutation of genes encoding proteins of diverse function. Despite modern therapy, dilated cardiomyopathy typically has a poor outcome and is the leading cause of cardiac transplantation. The phosphatase PP2A at cardiomyocyte perinuclear mAKAPβ signalosomes promotes pathological eccentric cardiac remodeling, as is characteristic of dilated cardiomyopathy. Displacement of PP2A from mAKAPβ, inhibiting PP2A function in that intracellular compartment, can be achieved by expression of a mAKAPβ-derived PP2A binding domain-derived peptide. To test whether PP2A anchoring disruption would be effective at preventing dilated cardiomyopathy-associated cardiac dysfunction, the adeno-associated virus gene therapy vector AAV9sc.PBD was devised to express the disrupting peptide in cardiomyocytes in vivo. Proof-of-concept is now provided that AAV9sc.PBD improves the cardiac structure and function of a cardiomyopathy mouse model involving transgenic expression of a mutant α-tropomyosin E54K Tpm1 allele, while AAV9sc.PBD has no effect on normal non-transgenic mice. At the cellular level, AAV9sc.PBD restores cardiomyocyte morphology and gene expression in the mutant Tpm1 mouse. As the mechanism of AAV9sc.PBD action suggests potential efficacy in dilated cardiomyopathy regardless of the underlying etiology, these data support the further testing of AAV9sc.PBD as a broad-based treatment for dilated cardiomyopathy.
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Affiliation(s)
- Xueyi Li
- Stanford Cardiovascular Institute, Departments of Ophthalmology and Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Jinliang Li
- Stanford Cardiovascular Institute, Departments of Ophthalmology and Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Anne-Maj Samuelsson
- Stanford Cardiovascular Institute, Departments of Ophthalmology and Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Hrishikesh Thakur
- Stanford Cardiovascular Institute, Departments of Ophthalmology and Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Michael S. Kapiloff
- Stanford Cardiovascular Institute, Departments of Ophthalmology and Medicine, Stanford University, Palo Alto, CA 94304, USA
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2
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Golatkar V, Bhatt LK. mAKAPβ signalosome: A potential target for cardiac hypertrophy. Drug Dev Res 2023; 84:1072-1084. [PMID: 37203301 DOI: 10.1002/ddr.22081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 03/05/2023] [Accepted: 05/06/2023] [Indexed: 05/20/2023]
Abstract
Pathological cardiac hypertrophy is the result of a prolonged increase in the workload of the heart that activates various signaling pathways such as MAPK pathway, PKA-dependent cAMP signaling, and CaN-NFAT signaling pathway which further activates genes for cardiac remodeling. Various signalosomes are present in the heart that regulates the signaling of physiological and pathological cardiac hypertrophy. mAKAPβ is one such scaffold protein that regulates signaling pathways involved in promoting cardiac hypertrophy. It is present in the outer nuclear envelope of the cardiomyocytes, which provides specificity of the target toward the heart. In addition, nuclear translocation of signaling components and transcription factors such as MEF2D, NFATc, and HIF-1α is facilitated due to the localization of mAKAPβ near the nuclear envelope. These factors are required for activation of genes promoting cardiac remodeling. Downregulation of mAKAPβ improves cardiac function and attenuates cardiac hypertrophy which in turn prevents the development of heart failure. Unlike earlier therapies for heart failure, knockout or silencing of mAKAPβ is not associated with side effects because of its high specificity in the striated myocytes. Downregulating expression of mAKAPβ is a favorable therapeutic approach toward attenuating cardiac hypertrophy and hence preventing heart failure. This review discusses mAKAPβ signalosome as a potential target for cardiac hypertrophy intervention.
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Affiliation(s)
- Vaishnavi Golatkar
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
| | - Lokesh K Bhatt
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (W), Mumbai, India
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3
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Martinez EC, Li J, Ataam JA, Tokarski K, Thakur H, Karakikes I, Dodge-Kafka K, Kapiloff MS. Targeting mAKAPβ expression as a therapeutic approach for ischemic cardiomyopathy. Gene Ther 2023; 30:543-551. [PMID: 35102273 PMCID: PMC9339585 DOI: 10.1038/s41434-022-00321-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 01/02/2023]
Abstract
Ischemic cardiomyopathy is a leading cause of death and an unmet clinical need. Adeno-associated virus (AAV) gene-based therapies hold great promise for treating and preventing heart failure. Previously we showed that muscle A-kinase Anchoring Protein β (mAKAPβ, AKAP6β), a scaffold protein that organizes perinuclear signalosomes in the cardiomyocyte, is a critical regulator of pathological cardiac hypertrophy. Here, we show that inhibition of mAKAPβ expression in stressed adult cardiomyocytes in vitro was cardioprotective, while conditional cardiomyocyte-specific mAKAP gene deletion in mice prevented pathological cardiac remodeling due to myocardial infarction. We developed a new self-complementary serotype 9 AAV gene therapy vector expressing a short hairpin RNA for mAKAPβ under the control of a cardiomyocyte-specific promoter (AAV9sc.shmAKAP). This vector efficiently downregulated mAKAPβ expression in the mouse heart in vivo. Expression of the shRNA also inhibited mAKAPβ expression in human induced cardiomyocytes in vitro. Following myocardial infarction, systemic administration of AAV9sc.shmAKAP prevented the development of pathological cardiac remodeling and heart failure, providing long-term restoration of left ventricular ejection fraction. Our findings provide proof-of-concept for mAKAPβ as a therapeutic target for ischemic cardiomyopathy and support the development of a translational pipeline for AAV9sc.shmAKAP for the treatment of heart failure.
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Affiliation(s)
- Eliana C Martinez
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33101, USA
| | - Jinliang Li
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33101, USA
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, 94304, USA
| | - Jennifer Arthur Ataam
- Department of Cardiothoracic Surgery and Stanford Cardiovascular Institute, Stanford University, Stanford, CA, 94305, USA
| | - Kristin Tokarski
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Hrishikesh Thakur
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33101, USA
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, 94304, USA
| | - Ioannis Karakikes
- Department of Cardiothoracic Surgery and Stanford Cardiovascular Institute, Stanford University, Stanford, CA, 94305, USA
| | - Kimberly Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | - Michael S Kapiloff
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33101, USA.
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, 94304, USA.
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Collins KB, Scott JD. Phosphorylation, compartmentalization, and cardiac function. IUBMB Life 2023; 75:353-369. [PMID: 36177749 PMCID: PMC10049969 DOI: 10.1002/iub.2677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022]
Abstract
Protein phosphorylation is a fundamental element of cell signaling. First discovered as a biochemical switch in glycogen metabolism, we now know that this posttranslational modification permeates all aspects of cellular behavior. In humans, over 540 protein kinases attach phosphate to acceptor amino acids, whereas around 160 phosphoprotein phosphatases remove phosphate to terminate signaling. Aberrant phosphorylation underlies disease, and kinase inhibitor drugs are increasingly used clinically as targeted therapies. Specificity in protein phosphorylation is achieved in part because kinases and phosphatases are spatially organized inside cells. A prototypic example is compartmentalization of the cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A through association with A-kinase anchoring proteins. This configuration creates autonomous signaling islands where the anchored kinase is constrained in proximity to activators, effectors, and selected substates. This article primarily focuses on A kinase anchoring protein (AKAP) signaling in the heart with an emphasis on anchoring proteins that spatiotemporally coordinate excitation-contraction coupling and hypertrophic responses.
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Affiliation(s)
- Kerrie B. Collins
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
| | - John D. Scott
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
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Turcotte MG, Thakur H, Kapiloff MS, Dodge-Kafka KL. A perinuclear calcium compartment regulates cardiac myocyte hypertrophy. J Mol Cell Cardiol 2022; 172:26-40. [PMID: 35952391 PMCID: PMC9727780 DOI: 10.1016/j.yjmcc.2022.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 06/16/2022] [Accepted: 07/18/2022] [Indexed: 12/14/2022]
Abstract
The pleiotropic Ca2+/calmodulin-dependent phosphatase calcineurin is a key regulator of pathological cardiac myocyte hypertrophy. The selective activation of hypertrophic calcineurin signaling under stress conditions has been attributed to compartmentation of Ca2+ signaling in cardiac myocytes. Here, perinuclear signalosomes organized by the scaffold protein muscle A-Kinase Anchoring Protein β (mAKAPβ/AKAP6β) are shown to orchestrate local Ca2+ transients, inducing calcineurin-dependent NFATc nuclear localization and myocyte hypertrophy in response to β-adrenergic receptor activation. Fluorescent biosensors for Ca2+ and calcineurin and protein kinase A (PKA) activity, both diffusely expressed and localized by nesprin-1α to the nuclear envelope, are used to define an autonomous mAKAPβ signaling compartment in adult and neonatal rat ventricular myocytes. Notably, β-adrenergic-stimulated perinuclear Ca2+ and PKA and CaN activity transients depended upon mAKAPβ expression, while Ca2+ elevation and PKA and CaN activity in the cytosol were mAKAPβ independent. Buffering perinuclear cAMP and Ca2+ prevented calcineurin-dependent NFATc nuclear translocation and myocyte hypertrophy, without affecting cardiac myocyte contractility. Additional findings suggest that the perinuclear Ca2+ transients were mediated by signalosome-associated ryanodine receptors regulated by local PKA phosphorylation. These results demonstrate the existence of a functionally independent Ca2+ signaling compartment in the cardiac myocyte regulating hypertrophy and provide a premise for targeting mAKAPβ signalosomes to prevent selectively cardiac hypertrophy in disease.
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Affiliation(s)
- Moriah Gildart Turcotte
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Hrishikesh Thakur
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA 94304, USA
| | - Kimberly L Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT 06030, USA.
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Jiang X, Cao M, Wu J, Wang X, Zhang G, Yang C, Gao P, Zou Y. Protections of transcription factor BACH2 and natural product myricetin against pathological cardiac hypertrophy and dysfunction. Front Physiol 2022; 13:971424. [PMID: 36105283 PMCID: PMC9465486 DOI: 10.3389/fphys.2022.971424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Pathological hypertrophic myocardium under consistent adverse stimuli eventually can cause heart failure. This study aims to explore the role of BACH2, a member of the basic region leucine zipper transcription factor family, in cardiac hypertrophy and failure. Transverse aortic constriction surgery was operated to induce cardiac hypertrophy and failure in mice. BACH2 was overexpressed in mice through tail vein injection of AAV9-Bach2. Mice with systemic or cardiac-specific knockdown of Bach2 were adopted. Neonatal rat ventricular myocytes (NRVMs) were isolated and infected with lentivirus to overexpress Bach2 or transfected with siRNA to knock down Bach2. Our data showed that overexpression of BACH2 ameliorated TAC-induced cardiac hypertrophy and failure in mice and decreased isoproterenol (ISO)-triggered myocyte hypertrophy in NRVMs. Systemic or cardiac-specific knockdown of Bach2 worsened the cardiac hypertrophy and failure phenotype in mice. Further assays showed that BACH2 bound to the promotor region of Akap6 at the -600 to -587 site and repressed its expression, which functioned as a crucial scaffold for cardiac hypertrophy and failure signaling pathways. Small molecular natural product library screening suggested that myricetin could up-regulate expression of Bach2 and simultaneously suppress the transcriptional levels of hypertrophic marker genes Bnp and Myh7. Further studies showed that myricetin exerted a BACH2-dependent protective effect against cardiac hypertrophy in vivo and in vitro. Taken together, our findings demonstrated that BACH2 plays a crucial role in the regulation of cardiac hypertrophy and failure and can be a potential therapeutic target in the future.
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Affiliation(s)
| | | | | | | | | | | | - Pan Gao
- *Correspondence: Yunzeng Zou, ; Pan Gao,
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Liu Q, Sun J, Dong Y, Li P, Wang J, Wang Y, Xu Y, Tian X, Wu B, He P, Yu Q, Lu X, Cao J. Tetramisole is a new I K1 channel agonist and exerts I K1 -dependent cardioprotective effects in rats. Pharmacol Res Perspect 2022; 10:e00992. [PMID: 35880674 PMCID: PMC9316008 DOI: 10.1002/prp2.992] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/22/2022] [Accepted: 07/04/2022] [Indexed: 11/30/2022] Open
Abstract
Cardiac ischemia, hypoxia, arrhythmias, and heart failure share the common electrophysiological changes featured by the elevation of intracellular Ca2+ (Ca2+ overload) and inhibition of the inward rectifier potassium (IK1 ) channel. IK1 channel agonists have been considered a new type of anti-arrhythmia and cardioprotective agents. We predicted using a drug repurposing strategy that tetramisole (Tet), a known anthelminthic agent, was a new IK1 channel agonist. The present study aimed to experimentally identify the above prediction and further demonstrate that Tet has cardioprotective effects. Results of the whole-cell patch clamp technique showed that Tet at 1-100 μmol/L enhanced IK1 current, hyperpolarized resting potential (RP), and shortened action potential duration (APD) in isolated rat cardiomyocytes, while without effects on other ion channels or transporters. In adult Sprague-Dawley (SD) rats in vivo, Tet showed anti-arrhythmia and anticardiac remodeling effects, respectively, in the coronary ligation-induced myocardial infarction model and isoproterenol (Iso, i.p., 3 mg/kg/day, 10 days) infusion-induced cardiac remodeling model. Tet also showed anticardiomyocyte remodeling effect in Iso (1 μmol/L) infused adult rat ventricular myocytes or cultured H9c2 (2-1) cardiomyocytes. Tet at 0.54 mg/kg in vivo or 30 μmol/L in vitro showed promising protections on acute ischemic arrhythmias, myocardial hypertrophy, and fibrosis. Molecular docking was performed and identified the selective binding of Tet with Kir2.1. The cardioprotection of Tet was associated with the facilitation of IK1 channel forward trafficking, deactivation of PKA signaling, and inhibition of intracellular calcium overload. Enhancing IK1 may play dual roles in anti-arrhythmia and antiventricular remodeling mediated by restoration of Ca2+ homeostasis.
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Affiliation(s)
- Qinghua Liu
- Department of PathophysiologyShanxi Medical UniversityTaiyuanChina
| | - Jiaxing Sun
- Department of PathophysiologyShanxi Medical UniversityTaiyuanChina
| | - Yangdou Dong
- Department of PathophysiologyShanxi Medical UniversityTaiyuanChina
| | - Pan Li
- Department of PathophysiologyShanxi Medical UniversityTaiyuanChina
| | - Jin Wang
- Key Laboratory of Cellular Physiology, Ministry of EducationShanxi Medical UniversityTaiyuanChina
- Department of PhysiologyShanxi Medical UniversityTaiyuanChina
| | - Yulan Wang
- Key Laboratory of Cellular Physiology, Ministry of EducationShanxi Medical UniversityTaiyuanChina
- Department of PhysiologyShanxi Medical UniversityTaiyuanChina
| | - Yanwu Xu
- Department of BiochemistryShanghai University of Traditional Chinese MedicineShanghaiChina
| | - Xinrui Tian
- Department of Respiratory and Critical Care MedicineSecond Hospital of Shanxi Medical UniversityTaiyuanChina
| | - Bowei Wu
- Key Laboratory of Cellular Physiology, Ministry of EducationShanxi Medical UniversityTaiyuanChina
- Department of PhysiologyShanxi Medical UniversityTaiyuanChina
| | - Peifeng He
- Shanxi Key Laboratory of Big Data for Clinical Decision Research, School of ManagementShanxi Medical UniversityTaiyuanChina
| | - Qi Yu
- Shanxi Key Laboratory of Big Data for Clinical Decision Research, School of ManagementShanxi Medical UniversityTaiyuanChina
| | - Xuechun Lu
- Department of Hematology, The Second Medical Center, Chinese PLA General HospitalNational clinical research center for geriatric diseaseBeijingChina
| | - Jimin Cao
- Key Laboratory of Cellular Physiology, Ministry of EducationShanxi Medical UniversityTaiyuanChina
- Department of PhysiologyShanxi Medical UniversityTaiyuanChina
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8
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Kocik RA, Gasch AP. Breadth and Specificity in Pleiotropic Protein Kinase A Activity and Environmental Responses. Front Cell Dev Biol 2022; 10:803392. [PMID: 35252178 PMCID: PMC8888911 DOI: 10.3389/fcell.2022.803392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 02/03/2022] [Indexed: 11/13/2022] Open
Abstract
Protein Kinase A (PKA) is an essential kinase that is conserved across eukaryotes and plays fundamental roles in a wide range of organismal processes, including growth control, learning and memory, cardiovascular health, and development. PKA mediates these responses through the direct phosphorylation of hundreds of proteins-however, which proteins are phosphorylated can vary widely across cell types and environmental cues, even within the same organism. A major question is how cells enact specificity and precision in PKA activity to mount the proper response, especially during environmental changes in which only a subset of PKA-controlled processes must respond. Research over the years has uncovered multiple strategies that cells use to modulate PKA activity and specificity. This review highlights recent advances in our understanding of PKA signaling control including subcellular targeting, phase separation, feedback control, and standing waves of allosteric regulation. We discuss how the complex inputs and outputs to the PKA network simultaneously pose challenges and solutions in signaling integration and insulation. PKA serves as a model for how the same regulatory factors can serve broad pleiotropic functions but maintain specificity in localized control.
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Affiliation(s)
- Rachel A Kocik
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI, United States.,Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, United States
| | - Audrey P Gasch
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, United States.,Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, United States
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Howlett LA, Kirton HM, Al‐Owais MM, Steele D, Lancaster MK. Action potential responses to changes in stimulation frequency and isoproterenol in rat ventricular myocytes. Physiol Rep 2022; 10:e15166. [PMID: 35076184 PMCID: PMC8787729 DOI: 10.14814/phy2.15166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/16/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023] Open
Abstract
PURPOSE Current understanding of ventricular action potential adaptation to physiological stress is generally based on protocols using non-physiological rates and conditions isolating rate effects from escalating adrenergic stimulation. To permit refined understanding, ventricular action potentials were assessed across physiological pacing frequencies in the presence and absence of adrenergic stimuli. Isolated and combined effects were analyzed to assess their ability to replicate in-vivo responses. METHODS Steady-state action potentials from ventricular myocytes isolated from male Wistar rats (3 months; N = 8 animals) were recorded at 37°C with steady-state pacing at 1, 2, 4, 6, 8 and 10 Hz using whole-cell patch-clamp. Action potential repolarization to 25, 50, 75, 90 and 100% of full repolarization (APD25-100 ) was compared before and after 5 nM, 100 nM and 1 µM isoproterenol doses. RESULTS A Repeated measures ANOVA found APD50-90 shortened with 5 nM isoproterenol infusion by 6-25% (but comparable across doses) (p ≤ 0.03). Pacing frequencies emulating a normal rat heart rate (6 Hz) prolonged APD50 23% compared with 1 Hz pacing. Frequencies emulating exercise or stress (10 Hz) shortened APD90 (29%). CONCLUSION These results demonstrate modest action potential shortening in response to adrenergic stimulation and elevations in pacing beyond physiological resting rates. Our findings indicate changes in action potential plateau and late repolarization predominantly underlie simulated exercise responses in the rat heart. This work provides novel action potential reference data and will help model cardiac responses to physiological stimuli in the rat heart via computational techniques.
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Affiliation(s)
| | | | | | - Derek Steele
- Faculty of Biological SciencesUniversity of LeedsLeedsUK
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Chaklader M, Rothermel BA. Calcineurin in the heart: New horizons for an old friend. Cell Signal 2021; 87:110134. [PMID: 34454008 PMCID: PMC8908812 DOI: 10.1016/j.cellsig.2021.110134] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023]
Abstract
Calcineurin, also known as PP2B or PPP3, is a member of the PPP family of protein phosphatases that also includes PP1 and PP2A. Together these three phosphatases carryout the majority of dephosphorylation events in the heart. Calcineurin is distinct in that it is activated by the binding of calcium/calmodulin (Ca2+/CaM) and therefore acts as a node for integrating Ca2+ signals with changes in phosphorylation, two fundamental intracellular signaling cascades. In the heart, calcineurin is primarily thought of in the context of pathological cardiac remodeling, acting through the Nuclear Factor of Activated T-cell (NFAT) family of transcription factors. However, calcineurin activity is also essential for normal heart development and homeostasis in the adult heart. Furthermore, it is clear that NFAT-driven changes in transcription are not the only relevant processes initiated by calcineurin in the setting of pathological remodeling. There is a growing appreciation for the diversity of calcineurin substrates that can impact cardiac function as well as the diversity of mechanisms for targeting calcineurin to specific sub-cellular domains in cardiomyocytes and other cardiac cell types. Here, we will review the basics of calcineurin structure, regulation, and function in the context of cardiac biology. Particular attention will be given to: the development of improved tools to identify and validate new calcineurin substrates; recent studies identifying new calcineurin isoforms with unique properties and targeting mechanisms; and the role of calcineurin in cardiac development and regeneration.
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Affiliation(s)
- Malay Chaklader
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Beverly A Rothermel
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
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11
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Howlett LA, Lancaster MK. Reduced cardiac response to the adrenergic system is a key limiting factor for physical capacity in old age. Exp Gerontol 2021; 150:111339. [PMID: 33838216 DOI: 10.1016/j.exger.2021.111339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 10/21/2022]
Abstract
Ageing is associated with a progressive reduction in physical capacity reducing quality of life. One key physiological limitation of physical capacity that deteriorates in a progressive age-dependent manner is cardiac reserve. Peak cardiac output falls progressively with advancing age such that in extreme old age there is limited ability to enhance cardiac output beyond basal function as is required to support the increased metabolic needs of physical activity. This loss of dynamic range in cardiac output associates with a progressive reduction in the heart's response to adrenergic stimulation. A combination of decreases in the expression and functioning of beta1 adrenergic receptors partially underlies this change. Changes in end effector proteins also have a role to play in this decline. Alterations in the efficiency of excitation-contraction coupling contribute to the reduced chronotropic, inotropic and lusitropic responses of the aged heart. Moderate to vigorous endurance exercise training however has some potential to counter elements of these changes. Further studies are required to fully elucidate the key pivotal mechanisms involved in the age-related loss of response to adrenergic signalling to allow targeted therapeutic strategies to be developed with the aim of preserving physical capacity in advanced old age.
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Affiliation(s)
- Luke A Howlett
- Faculty of Biological Sciences, University of Leeds, LS2 9JT, UK.
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cAMP at Perinuclear mAKAPα Signalosomes Is Regulated by Local Ca 2+ Signaling in Primary Hippocampal Neurons. eNeuro 2021; 8:ENEURO.0298-20.2021. [PMID: 33495246 PMCID: PMC7920539 DOI: 10.1523/eneuro.0298-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/07/2021] [Accepted: 01/10/2021] [Indexed: 12/14/2022] Open
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) is important for the regulation of neuronal structure and function, including neurite extension. A perinuclear cAMP compartment organized by the scaffold protein muscle A-kinase anchoring protein α (mAKAPα/AKAP6α) is sufficient and necessary for axon growth by rat hippocampal neurons in vitro. Here, we report that cAMP at mAKAPα signalosomes is regulated by local Ca2+ signaling that mediates activity-dependent cAMP elevation within that compartment. Simultaneous Forster resonance energy transfer (FRET) imaging using the protein kinase A (PKA) activity reporter AKAR4 and intensiometric imaging using the RCaMP1h fluorescent Ca2+ sensor revealed that membrane depolarization by KCl selectively induced activation of perinuclear PKA activity. Activity-dependent perinuclear PKA activity was dependent on expression of the mAKAPα scaffold, while both perinuclear Ca2+ elevation and PKA activation were dependent on voltage-dependent L-type Ca2+ channel activity. Importantly, chelation of Ca2+ by a nuclear envelope-localized parvalbumin fusion protein inhibited both activity-induced perinuclear PKA activity and axon elongation. Together, this study provides evidence for a model in which a neuronal perinuclear cAMP compartment is locally regulated by activity-dependent Ca2+ influx, providing local control for the enhancement of neurite extension.
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13
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Liu Y, Chen J, Fontes SK, Bautista EN, Cheng Z. Physiological And Pathological Roles Of Protein Kinase A In The Heart. Cardiovasc Res 2021; 118:386-398. [PMID: 33483740 DOI: 10.1093/cvr/cvab008] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 12/21/2022] Open
Abstract
Protein kinase A (PKA) is a central regulator of cardiac performance and morphology. Myocardial PKA activation is induced by a variety of hormones, neurotransmitters and stress signals, most notably catecholamines secreted by the sympathetic nervous system. Catecholamines bind β-adrenergic receptors to stimulate cAMP-dependent PKA activation in cardiomyocytes. Elevated PKA activity enhances Ca2+ cycling and increases cardiac muscle contractility. Dynamic control of PKA is essential for cardiac homeostasis, as dysregulation of PKA signaling is associated with a broad range of heart diseases. Specifically, abnormal PKA activation or inactivation contributes to the pathogenesis of myocardial ischemia, hypertrophy, heart failure, as well as diabetic, takotsubo, or anthracycline cardiomyopathies. PKA may also determine sex-dependent differences in contractile function and heart disease predisposition. Here, we describe the recent advances regarding the roles of PKA in cardiac physiology and pathology, highlighting previous study limitations and future research directions. Moreover, we discuss the therapeutic strategies and molecular mechanisms associated with cardiac PKA biology. In summary, PKA could serve as a promising drug target for cardioprotection. Depending on disease types and mechanisms, therapeutic intervention may require either inhibition or activation of PKA. Therefore, specific PKA inhibitors or activators may represent valuable drug candidates for the treatment of heart diseases.
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Affiliation(s)
- Yuening Liu
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Jingrui Chen
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Shayne K Fontes
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Erika N Bautista
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Zhaokang Cheng
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
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14
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Li J, Tan Y, Passariello CL, Martinez EC, Kritzer MD, Li X, Li X, Li Y, Yu Q, Ohgi K, Thakur H, MacArthur JW, Ivey JR, Woo YJ, Emter CA, Dodge-Kafka K, Rosenfeld MG, Kapiloff MS. Signalosome-Regulated Serum Response Factor Phosphorylation Determining Myocyte Growth in Width Versus Length as a Therapeutic Target for Heart Failure. Circulation 2020; 142:2138-2154. [PMID: 32933333 DOI: 10.1161/circulationaha.119.044805] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Concentric and eccentric cardiac hypertrophy are associated with pressure and volume overload, respectively, in cardiovascular disease both conferring an increased risk of heart failure. These contrasting forms of hypertrophy are characterized by asymmetrical growth of the cardiac myocyte in mainly width or length, respectively. The molecular mechanisms determining myocyte preferential growth in width versus length remain poorly understood. Identification of the mechanisms governing asymmetrical myocyte growth could provide new therapeutic targets for the prevention or treatment of heart failure. METHODS Primary adult rat ventricular myocytes, adeno-associated virus (AAV)-mediated gene delivery in mice, and human tissue samples were used to define a regulatory pathway controlling pathological myocyte hypertrophy. Chromatin immunoprecipitation assays with sequencing and precision nuclear run-on sequencing were used to define a transcriptional mechanism. RESULTS We report that asymmetrical cardiac myocyte hypertrophy is modulated by SRF (serum response factor) phosphorylation, constituting an epigenomic switch balancing the growth in width versus length of adult ventricular myocytes in vitro and in vivo. SRF Ser103 phosphorylation is bidirectionally regulated by RSK3 (p90 ribosomal S6 kinase type 3) and PP2A (protein phosphatase 2A) at signalosomes organized by the scaffold protein mAKAPβ (muscle A-kinase anchoring protein β), such that increased SRF phosphorylation activates AP-1 (activator protein-1)-dependent enhancers that direct myocyte growth in width. AAV are used to express in vivo mAKAPβ-derived RSK3 and PP2A anchoring disruptor peptides that block the association of the enzymes with the mAKAPβ scaffold. Inhibition of RSK3 signaling prevents concentric cardiac remodeling induced by pressure overload, while inhibition of PP2A signaling prevents eccentric cardiac remodeling induced by myocardial infarction, in each case improving cardiac function. SRF Ser103 phosphorylation is significantly decreased in dilated human hearts, supporting the notion that modulation of the mAKAPβ-SRF signalosome could be a new therapeutic approach for human heart failure. CONCLUSIONS We have identified a new molecular switch, namely mAKAPβ signalosome-regulated SRF phosphorylation, that controls a transcriptional program responsible for modulating changes in cardiac myocyte morphology that occur secondary to pathological stressors. Complementary AAV-based gene therapies constitute rationally-designed strategies for a new translational modality for heart failure.
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Affiliation(s)
- Jinliang Li
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.).,Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | - Yuliang Tan
- Howard Hughes Medical Institute, Department of Medicine, University of California, San Diego, La Jolla, CA (Y.T., K.O., M.G.R.)
| | - Catherine L Passariello
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | - Eliana C Martinez
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | - Michael D Kritzer
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | - Xueyi Li
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.)
| | - Xiaofeng Li
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | - Yang Li
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.)
| | - Qian Yu
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.)
| | - Kenneth Ohgi
- Howard Hughes Medical Institute, Department of Medicine, University of California, San Diego, La Jolla, CA (Y.T., K.O., M.G.R.)
| | - Hrishikesh Thakur
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.).,Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
| | | | - Jan R Ivey
- Department of Biomedical Sciences, University of Missouri-Columbia (J.R.I., C.A.E.)
| | - Y Joseph Woo
- Department of Cardiothoracic Surgery, Stanford University, CA (Y.J.W.)
| | - Craig A Emter
- Department of Biomedical Sciences, University of Missouri-Columbia (J.R.I., C.A.E.)
| | - Kimberly Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington (K.D-K.)
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department of Medicine, University of California, San Diego, La Jolla, CA (Y.T., K.O., M.G.R.)
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Xueyi Li, Y. L., Q.Y., H.T., M.S.K.).,Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (J.L., C.L.P., E.C.M., M.D.K., Xiaofeng Li, H.T., M.S.K.)
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15
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Affiliation(s)
- Kathleen C Woulfe
- Department of Medicine, Division of Cardiology (K.C.W., J.G.T., T.A.M.), University of Colorado Anschutz Medical Campus, Aurora
| | - Joshua G Travers
- Department of Medicine, Division of Cardiology (K.C.W., J.G.T., T.A.M.), University of Colorado Anschutz Medical Campus, Aurora.,Consortium for Fibrosis Research & Translation (J.G.T., T.A.M.), University of Colorado Anschutz Medical Campus, Aurora
| | - Timothy A McKinsey
- Department of Medicine, Division of Cardiology (K.C.W., J.G.T., T.A.M.), University of Colorado Anschutz Medical Campus, Aurora.,Consortium for Fibrosis Research & Translation (J.G.T., T.A.M.), University of Colorado Anschutz Medical Campus, Aurora
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16
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Li X, Li J, Martinez EC, Froese A, Passariello CL, Henshaw K, Rusconi F, Li Y, Yu Q, Thakur H, Nikolaev VO, Kapiloff MS. Calcineurin Aβ-Specific Anchoring Confers Isoform-Specific Compartmentation and Function in Pathological Cardiac Myocyte Hypertrophy. Circulation 2020; 142:948-962. [PMID: 32611257 DOI: 10.1161/circulationaha.119.044893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The Ca2+/calmodulin-dependent phosphatase calcineurin is a key regulator of cardiac myocyte hypertrophy in disease. An unexplained paradox is how the β isoform of the calcineurin catalytic A-subunit (CaNAβ) is required for induction of pathological myocyte hypertrophy, despite calcineurin Aα expression in the same cells. It is unclear how the pleiotropic second messenger Ca2+ drives excitation-contraction coupling while not stimulating hypertrophy by calcineurin in the normal heart. Elucidation of the mechanisms conferring this selectivity in calcineurin signaling should reveal new strategies for targeting the phosphatase in disease. METHODS Primary adult rat ventricular myocytes were studied for morphology and intracellular signaling. New Förster resonance energy transfer reporters were used to assay Ca2+ and calcineurin activity in living cells. Conditional gene deletion and adeno-associated virus-mediated gene delivery in the mouse were used to study calcineurin signaling after transverse aortic constriction in vivo. RESULTS CIP4 (Cdc42-interacting protein 4)/TRIP10 (thyroid hormone receptor interactor 10) was identified as a new polyproline domain-dependent scaffold for CaNAβ2 by yeast 2-hybrid screen. Cardiac myocyte-specific CIP4 gene deletion in mice attenuated pressure overload-induced pathological cardiac remodeling and heart failure. Blockade of CaNAβ polyproline-dependent anchoring using a competing peptide inhibited concentric hypertrophy in cultured myocytes; disruption of anchoring in vivo using an adeno-associated virus gene therapy vector inhibited cardiac hypertrophy and improved systolic function after pressure overload. Live cell Förster resonance energy transfer biosensor imaging of cultured myocytes revealed that Ca2+ levels and calcineurin activity associated with the CIP4 compartment were increased by neurohormonal stimulation, but minimally by pacing. Conversely, Ca2+ levels and calcineurin activity detected by nonlocalized Förster resonance energy transfer sensors were induced by pacing and minimally by neurohormonal stimulation, providing functional evidence for differential intracellular compartmentation of Ca2+ and calcineurin signal transduction. CONCLUSIONS These results support a structural model for Ca2+ and CaNAβ compartmentation in cells based on an isoform-specific mechanism for calcineurin protein-protein interaction and localization. This mechanism provides an explanation for the specific role of CaNAβ in hypertrophy and its selective activation under conditions of pathologic stress. Disruption of CaNAβ polyproline-dependent anchoring constitutes a rational strategy for therapeutic targeting of CaNAβ-specific signaling responsible for pathological cardiac remodeling in cardiovascular disease deserving of further preclinical investigation.
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Affiliation(s)
- Xiaofeng Li
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.)
| | - Jinliang Li
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.).,Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Y.L., Q.Y., H.T., M.S.K.)
| | - Eliana C Martinez
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.)
| | - Alexander Froese
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (A.F., V.O.N.)
| | - Catherine L Passariello
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.)
| | - Kathryn Henshaw
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.)
| | - Francesca Rusconi
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.)
| | - Yang Li
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Y.L., Q.Y., H.T., M.S.K.)
| | - Qian Yu
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Y.L., Q.Y., H.T., M.S.K.)
| | - Hrishikesh Thakur
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.).,Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Y.L., Q.Y., H.T., M.S.K.)
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (A.F., V.O.N.)
| | - Michael S Kapiloff
- Interdisciplinary Stem Cell Institute, Department of Pediatrics, Leonard M. Miller School of Medicine, University of Miami, FL (X.L., J.L., E.C.M., C.L.P., K.H., F.R., H.T., M.S.K.).,Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA (J.L., Y.L., Q.Y., H.T., M.S.K.)
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17
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Bedioune I, Lefebvre F, Lechêne P, Varin A, Domergue V, Kapiloff MS, Fischmeister R, Vandecasteele G. PDE4 and mAKAPβ are nodal organizers of β2-ARs nuclear PKA signalling in cardiac myocytes. Cardiovasc Res 2019; 114:1499-1511. [PMID: 29733383 DOI: 10.1093/cvr/cvy110] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 04/27/2018] [Indexed: 01/04/2023] Open
Abstract
Aims β1- and β2-adrenergic receptors (β-ARs) produce different acute contractile effects on the heart partly because they impact on different cytosolic pools of cAMP-dependent protein kinase (PKA). They also exert different effects on gene expression but the underlying mechanisms remain unknown. The aim of this study was to understand the mechanisms by which β1- and β2-ARs regulate nuclear PKA activity in cardiomyocytes. Methods and results We used cytoplasmic and nuclear targeted biosensors to examine cAMP signals and PKA activity in adult rat ventricular myocytes upon selective β1- or β2-ARs stimulation. Both β1- and β2-AR stimulation increased cAMP and activated PKA in the cytoplasm. Although the two receptors also increased cAMP in the nucleus, only β1-ARs increased nuclear PKA activity and up-regulated the PKA target gene and pro-apoptotic factor, inducible cAMP early repressor (ICER). Inhibition of phosphodiesterase (PDE)4, but not Gi, PDE3, GRK2 nor caveolae disruption disclosed nuclear PKA activation and ICER induction by β2-ARs. Both nuclear and cytoplasmic PKI prevented nuclear PKA activation and ICER induction by β1-ARs, indicating that PKA activation outside the nucleus is required for subsequent nuclear PKA activation and ICER mRNA expression. Cytoplasmic PKI also blocked ICER induction by β2-AR stimulation (with concomitant PDE4 inhibition). However, in this case nuclear PKI decreased ICER up-regulation by only 30%, indicating that other mechanisms are involved. Down-regulation of mAKAPβ partially inhibited nuclear PKA activation upon β1-AR stimulation, and drastically decreased nuclear PKA activation upon β2-AR stimulation in the presence of PDE4 inhibition. Conclusions β1- and β2-ARs differentially regulate nuclear PKA activity and ICER expression in cardiomyocytes. PDE4 insulates a mAKAPβ-targeted PKA pool at the nuclear envelope that prevents nuclear PKA activation upon β2-AR stimulation.
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Affiliation(s)
- Ibrahim Bedioune
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Univ. Paris-Sud, INSERM
| | - Florence Lefebvre
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Univ. Paris-Sud, INSERM
| | - Patrick Lechêne
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Univ. Paris-Sud, INSERM
| | - Audrey Varin
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Univ. Paris-Sud, INSERM
| | - Valérie Domergue
- Institut Paris Saclay d'Innovation Thérapeutique, UMS IPSIT, Univ. Paris-Sud, Université Paris-Saclay, F-92296 Châtenay-Malabry Cedex, France
| | - Michael S Kapiloff
- Cardiac Signal Transduction and Cellular Biology Laboratory, Departments of Pediatrics and Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, USA
| | - Rodolphe Fischmeister
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Univ. Paris-Sud, INSERM.,Institut Paris Saclay d'Innovation Thérapeutique, UMS IPSIT, Univ. Paris-Sud, Université Paris-Saclay, F-92296 Châtenay-Malabry Cedex, France
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18
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Hakem Zadeh F, Teng ACT, Kuzmanov U, Chambers PJ, Tupling AR, Gramolini AO. AKAP6 and phospholamban colocalize and interact in HEK-293T cells and primary murine cardiomyocytes. Physiol Rep 2019; 7:e14144. [PMID: 31325238 PMCID: PMC6642276 DOI: 10.14814/phy2.14144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/16/2019] [Accepted: 05/24/2019] [Indexed: 12/21/2022] Open
Abstract
Phospholamban (PLN) is an important Ca2+ modulator at the sarcoplasmic reticulum (SR) of striated muscles. It physically interacts and inhibits sarcoplasmic reticulum Ca2+ATPase (SERCA2) function, whereas a protein kinase A (PKA)‐dependent phosphorylation at its serine 16 reverses the inhibition. The underlying mechanism of this post‐translational modification, however, remains not fully understood. Using publicly available databases, we identified A‐kinase anchoring protein 6 (AKAP6) as a candidate that might play some roles in PLN phosphorylation. Immunofluorescence showed colocalization between GFP‐AKAP6 and PLN in transfected HEK‐293T cells and cultured mouse neonatal cardiomyocytes (CMNCs). Co‐immunoprecipitation confirmed the functional interaction between AKAP6 and PLN in HEK‐293T and isolated adult rat cardiomyocytes in response to isoproterenol stimulation. Functionally, AKAP6 promoted Ca2+ uptake activity of SERCA1 in cotransfected HEK‐293T cells despite the presence of PLN. These results were further confirmed in adult rat cardiomyocytes. Immunofluorescence showed colocalization of both proteins around the perinuclear region, while protein–protein interaction was corroborated by immunoprecipitation of the nucleus‐enriched fraction of rat hearts. Our findings suggest AKAP6 as a novel interacting partner to PLN in HEK‐293T and murine cardiomyocytes.
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Affiliation(s)
- Farigol Hakem Zadeh
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario.,Translational Biology and Engineering Program (TBEP), Ted Rogers Centre for Heart Research, Toronto, Ontario
| | - Allen C T Teng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario.,Translational Biology and Engineering Program (TBEP), Ted Rogers Centre for Heart Research, Toronto, Ontario
| | - Uros Kuzmanov
- Translational Biology and Engineering Program (TBEP), Ted Rogers Centre for Heart Research, Toronto, Ontario
| | - Paige J Chambers
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario
| | - Allan R Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario
| | - Anthony O Gramolini
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario.,Translational Biology and Engineering Program (TBEP), Ted Rogers Centre for Heart Research, Toronto, Ontario
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19
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Dodge-Kafka K, Gildart M, Tokarski K, Kapiloff MS. mAKAPβ signalosomes - A nodal regulator of gene transcription associated with pathological cardiac remodeling. Cell Signal 2019; 63:109357. [PMID: 31299211 PMCID: PMC7197268 DOI: 10.1016/j.cellsig.2019.109357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/01/2019] [Accepted: 07/05/2019] [Indexed: 12/14/2022]
Abstract
Striated myocytes compose about half of the cells of the heart, while contributing the majority of the heart's mass and volume. In response to increased demands for pumping power, including in diseases of pressure and volume overload, the contractile myocytes undergo non-mitotic growth, resulting in increased heart mass, i.e. cardiac hypertrophy. Myocyte hypertrophy is induced by a change in the gene expression program driven by the altered activity of transcription factors and co-repressor and co-activator chromatin-associated proteins. These gene regulatory proteins are subject to diverse post-translational modifications and serve as nuclear effectors for intracellular signal transduction pathways, including those controlled by cyclic nucleotides and calcium ion. Scaffold proteins contribute to the underlying architecture of intracellular signaling networks by targeting signaling enzymes to discrete intracellular compartments, providing specificity to the regulation of downstream effectors, including those regulating gene expression. Muscle A-kinase anchoring protein β (mAKAPβ) is a well-characterized scaffold protein that contributes to the regulation of pathological cardiac hypertrophy. In this review, we discuss the mechanisms how this prototypical scaffold protein organizes signalosomes responsible for the regulation of class IIa histone deacetylases and cardiac transcription factors such as NFAT, MEF2, and HIF-1α, as well as how this signalosome represents a novel therapeutic target for the prevention or treatment of heart failure.
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Affiliation(s)
- Kimberly Dodge-Kafka
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA.
| | - Moriah Gildart
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA
| | - Kristin Tokarski
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, USA
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20
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Regulation of Neuronal Survival and Axon Growth by a Perinuclear cAMP Compartment. J Neurosci 2019; 39:5466-5480. [PMID: 31097623 DOI: 10.1523/jneurosci.2752-18.2019] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 03/11/2019] [Accepted: 04/10/2019] [Indexed: 12/21/2022] Open
Abstract
cAMP signaling is known to be critical in neuronal survival and axon growth. Increasingly the subcellular compartmentation of cAMP signaling has been appreciated, but outside of dendritic synaptic regulation, few cAMP compartments have been defined in terms of molecular composition or function in neurons. Specificity in cAMP signaling is conferred in large part by A-kinase anchoring proteins (AKAPs) that localize protein kinase A and other signaling enzymes to discrete intracellular compartments. We now reveal that cAMP signaling within a perinuclear neuronal compartment organized by the large multivalent scaffold protein mAKAPα promotes neuronal survival and axon growth. mAKAPα signalosome function is explored using new molecular tools designed to specifically alter local cAMP levels as studied by live-cell FRET imaging. In addition, enhancement of mAKAPα-associated cAMP signaling by isoform-specific displacement of bound phosphodiesterase is demonstrated to increase retinal ganglion cell survival in vivo in mice of both sexes following optic nerve crush injury. These findings define a novel neuronal compartment that confers cAMP regulation of neuroprotection and axon growth and that may be therapeutically targeted in disease.SIGNIFICANCE STATEMENT cAMP is a second messenger responsible for the regulation of diverse cellular processes including neuronal neurite extension and survival following injury. Signal transduction by cAMP is highly compartmentalized in large part because of the formation of discrete, localized multimolecular signaling complexes by A-kinase anchoring proteins. Although the concept of cAMP compartmentation is well established, the function and identity of these compartments remain poorly understood in neurons. In this study, we provide evidence for a neuronal perinuclear cAMP compartment organized by the scaffold protein mAKAPα that is necessary and sufficient for the induction of neurite outgrowth in vitro and for the survival of retinal ganglion cells in vivo following optic nerve injury.
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21
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Grandi E, Ripplinger CM. Antiarrhythmic mechanisms of beta blocker therapy. Pharmacol Res 2019; 146:104274. [PMID: 31100336 DOI: 10.1016/j.phrs.2019.104274] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 05/04/2019] [Accepted: 05/13/2019] [Indexed: 02/07/2023]
Abstract
Sympathetic activity plays an important role in modulation of cardiac rhythm. Indeed, while exerting positive tropic effects in response to physiologic and pathologic stressors, β-adrenergic stimulation influences cardiac electrophysiology and can lead to disturbances of the heart rhythm and potentially lethal arrhythmias, particularly in pathological settings. For this reason, β-blockers are widely utilized clinically as antiarrhythmics. In this review, the molecular mechanisms of β-adrenergic action in the heart, the cellular and tissue level cardiac responses to β-adrenergic stimulation, and the clinical use of β-blockers as antiarrhythmic agents are reviewed. We emphasize the complex interaction between cardiomyocyte signaling, contraction, and electrophysiology occurring over multiple time- and spatial-scales during pathophysiological responses to β-adrenergic stimulation. An integrated understanding of this complex system is essential for optimizing therapies aimed at preventing arrhythmias.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California Davis, United States.
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22
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Gildart M, Kapiloff MS, Dodge-Kafka KL. Calcineurin-AKAP interactions: therapeutic targeting of a pleiotropic enzyme with a little help from its friends. J Physiol 2018; 598:3029-3042. [PMID: 30488951 PMCID: PMC7586300 DOI: 10.1113/jp276756] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/14/2018] [Indexed: 01/14/2023] Open
Abstract
The ubiquitous Ca2+ /calmodulin-dependent phosphatase calcineurin is a key regulator of pathological cardiac hypertrophy whose therapeutic targeting in heart disease has been elusive due to its role in other essential biological processes. Calcineurin is targeted to diverse intracellular compartments by association with scaffold proteins, including by multivalent A-kinase anchoring proteins (AKAPs) that bind protein kinase A and other important signalling enzymes determining cardiac myocyte function and phenotype. Calcineurin anchoring by AKAPs confers specificity to calcineurin function in the cardiac myocyte. Targeting of calcineurin 'signalosomes' may provide a rationale for inhibiting the phosphatase in disease.
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Affiliation(s)
- Moriah Gildart
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Cardiovascular Medicine, Byers Eye Institute and Spencer Center for Vision Research, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, USA
| | - Kimberly L Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, USA
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Li J, Aponte Paris S, Thakur H, Kapiloff MS, Dodge-Kafka KL. Muscle A-kinase-anchoring protein-β-bound calcineurin toggles active and repressive transcriptional complexes of myocyte enhancer factor 2D. J Biol Chem 2018; 294:2543-2554. [PMID: 30523159 DOI: 10.1074/jbc.ra118.005465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/04/2018] [Indexed: 12/13/2022] Open
Abstract
Myocyte enhancer factor 2 (MEF2) transcription factors are key regulators of the development and adult phenotype of diverse tissues, including skeletal and cardiac muscles. Controlled by multiple post-translational modifications, MEF2D is an effector for the Ca2+/calmodulin-dependent protein phosphatase calcineurin (CaN, PP2B, and PPP3). CaN-catalyzed dephosphorylation promotes the desumoylation and acetylation of MEF2D, increasing its transcriptional activity. Both MEF2D and CaN bind the scaffold protein muscle A-kinase-anchoring protein β (mAKAPβ), which is localized to the nuclear envelope, such that C2C12 skeletal myoblast differentiation and neonatal rat ventricular myocyte hypertrophy are inhibited by mAKAPβ signalosome targeting. Using immunoprecipitation and DNA-binding assays, we now show that the formation of mAKAPβ signalosomes is required for MEF2D dephosphorylation, desumoylation, and acetylation in C2C12 cells. Reduced MEF2D phosphorylation was coupled to a switch from type IIa histone deacetylase to p300 histone acetylase binding that correlated with increased MEF2D-dependent gene expression and ventricular myocyte hypertrophy. Together, these results highlight the importance of mAKAPβ signalosomes for regulating MEF2D activity in striated muscle, affirming mAKAPβ as a nodal regulator in the myocyte intracellular signaling network.
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Affiliation(s)
- Jinliang Li
- From the Departments of Ophthalmology and Cardiovascular Medicine, Byers Eye Institute, and Spencer Center for Vision Research, Stanford Cardiovascular Institute, Stanford University, Palo Alto, California 94304-1209 and
| | - Shania Aponte Paris
- the Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - Hrishikesh Thakur
- From the Departments of Ophthalmology and Cardiovascular Medicine, Byers Eye Institute, and Spencer Center for Vision Research, Stanford Cardiovascular Institute, Stanford University, Palo Alto, California 94304-1209 and
| | - Michael S Kapiloff
- From the Departments of Ophthalmology and Cardiovascular Medicine, Byers Eye Institute, and Spencer Center for Vision Research, Stanford Cardiovascular Institute, Stanford University, Palo Alto, California 94304-1209 and
| | - Kimberly L Dodge-Kafka
- the Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, Connecticut 06030
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Paruchuri S, Thodeti CK. Form follows function: polymorphisms in mAKAP alter cardiac cAMP/PKA signaling. Am J Physiol Heart Circ Physiol 2018; 315:H626-H628. [PMID: 29727216 DOI: 10.1152/ajpheart.00248.2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Charles K Thodeti
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio
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25
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Rababa'h AM, Guillory AN, Mustafa R, Hijjawi T. Oxidative Stress and Cardiac Remodeling: An Updated Edge. Curr Cardiol Rev 2018; 14:53-59. [PMID: 29332590 PMCID: PMC5872263 DOI: 10.2174/1573403x14666180111145207] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/24/2017] [Accepted: 01/03/2018] [Indexed: 01/21/2023] Open
Abstract
Background: A common phenotype associated with heart failure is the development of cardiac hypertrophy. Cardiac hypertrophy occurs in response to stress, such as hypertension, coro-nary vascular disease, or myocardial infarction. The most critical pathophysiological conditions in-volved may include dilated hypertrophy, fibrosis and contractile malfunction. The intricate pathophys-iological mechanisms of cardiac hypertrophy have been the core of several scientific studies, which may help in opening a new avenue in preventive and curative procedures. Objectives: To our knowledge from the literature, the development of cardiac remodeling and hyper-trophy is multifactorial. Thus, in this review, we will focus and summarize the potential role of oxida-tive stress in cardiac hypertrophy development. Conclusion: Oxidative stress is considered a major stimulant for the signal transduction in cardiac cells pathological conditions, including inflammatory cytokines, and MAP kinase. The understanding of the pathophysiological mechanisms which are involved in cardiac hypertrophy and remodeling process is crucial for the development of new therapeutic plans, especially that the mortality rates re-lated to cardiac remodeling/dysfunction remain high
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Affiliation(s)
- Abeer M Rababa'h
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Ashley N Guillory
- Department of Physician Assistant Studies, University of Texas Medical Branch, Galveston, Texas, TX, United States
| | - Rima Mustafa
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Tamara Hijjawi
- Department of Forensic Medicine and Toxicology, Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
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26
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Suryavanshi SV, Jadhav SM, Anderson KL, Katsonis P, Lichtarge O, McConnell BK. Human muscle-specific A-kinase anchoring protein polymorphisms modulate the susceptibility to cardiovascular diseases by altering cAMP/PKA signaling. Am J Physiol Heart Circ Physiol 2018; 315:H109-H121. [PMID: 29600899 DOI: 10.1152/ajpheart.00034.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
One of the crucial cardiac signaling pathways is cAMP-mediated PKA signal transduction, which is regulated by a family of scaffolding proteins, i.e., A-kinase anchoring proteins (AKAPs). Muscle-specific AKAP (mAKAP) partly regulates cardiac cAMP/PKA signaling by binding to PKA and phosphodiesterase 4D3 (PDE4D3), among other proteins, and plays a central role in modulating cardiac remodeling. Moreover, genetics plays an incomparable role in modifying the risk of cardiovascular diseases (CVDs). Single-nucleotide polymorphisms (SNPs) in various proteins have especially been shown to predispose individuals to CVDs. Hence, we hypothesized that human mAKAP polymorphisms found in humans with CVDs alter the cAMP/PKA pathway, influencing the susceptibility of individuals to CVDs. Our computational analyses revealed two mAKAP SNPs found in cardiac disease-related patients with the highest predicted deleterious effects, Ser 1653 Arg (S1653R) and Glu 2124 Gly (E2124G). Coimmunoprecipitation data in human embryonic kidney-293T cells showed that the S1653R SNP, present in the PDE4D3-binding domain of mAKAP, changed the binding of PDE4D3 to mAKAP and that the E2124G SNP, flanking the 3'-PKA binding domain, changed the binding of PKA before and after stimulation with isoproterenol. These SNPs significantly altered intracellular cAMP levels, global PKA activity, and cytosolic PDE activity compared with the wild type before and after isoproterenol stimulation. PKA-mediated phosphorylation of pathological markers was found to be upregulated after cell stimulation in both mutants. In conclusion, human mAKAP polymorphisms may influence the propensity of developing CVDs by affecting cAMP/PKA signaling, supporting the clinical significance of PKA-mAKAP-PDE4D3 interactions. NEW & NOTEWORTHY We found that single-nucleotide polymorphisms in muscle-specific A-kinase anchoring protein found in human patients with cardiovascular diseases significantly affect the cAMP/PKA signaling pathway. Our results showed, for the first time, that human muscle-specific A-kinase anchoring protein polymorphisms might alter the susceptibility of individuals to develop cardiovascular diseases with known underlying molecular mechanisms.
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Affiliation(s)
- Santosh V Suryavanshi
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, College of Pharmacy, Texas Medical Center , Houston, Texas
| | - Shweta M Jadhav
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, College of Pharmacy, Texas Medical Center , Houston, Texas
| | - Kody L Anderson
- Department of Chemical Engineering, University of Houston, Cullen College of Engineering , Houston, Texas
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine , Houston, Texas
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine , Houston, Texas
| | - Bradley K McConnell
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, College of Pharmacy, Texas Medical Center , Houston, Texas
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27
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Rababa'h AM, Guillory AN, Mustafa R, Hijjawi T. Oxidative Stress and Cardiac Remodeling: An Updated Edge. Curr Cardiol Rev 2018. [PMID: 29332590 DOI: 10.2174/1573403x14666180111145207.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A common phenotype associated with heart failure is the development of cardiac hypertrophy. Cardiac hypertrophy occurs in response to stress, such as hypertension, coronary vascular disease, or myocardial infarction. The most critical pathophysiological conditions involved may include dilated hypertrophy, fibrosis and contractile malfunction. The intricate pathophysiological mechanisms of cardiac hypertrophy have been the core of several scientific studies, which may help in opening a new avenue in preventive and curative procedures. OBJECTIVES To our knowledge from the literature, the development of cardiac remodeling and hypertrophy is multifactorial. Thus, in this review, we will focus and summarize the potential role of oxidative stress in cardiac hypertrophy development. CONCLUSION Oxidative stress is considered a major stimulant for the signal transduction in cardiac cells pathological conditions, including inflammatory cytokines, and MAP kinase. The understanding of the pathophysiological mechanisms which are involved in cardiac hypertrophy and remodeling process is crucial for the development of new therapeutic plans, especially that the mortality rates related to cardiac remodeling/dysfunction remain high.
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Affiliation(s)
- Abeer M Rababa'h
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Ashley N Guillory
- Department of Physician Assistant Studies, University of Texas Medical Branch, Galveston, Texas, TX, United States
| | - Rima Mustafa
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Tamara Hijjawi
- Department of Forensic Medicine and Toxicology, Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
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28
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Dodge-Kafka KL, Gildart M, Li J, Thakur H, Kapiloff MS. Bidirectional regulation of HDAC5 by mAKAPβ signalosomes in cardiac myocytes. J Mol Cell Cardiol 2018. [PMID: 29522762 DOI: 10.1016/j.yjmcc.2018.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Class IIa histone deacetylases (HDACs) are transcriptional repressors whose nuclear export in the cardiac myocyte is associated with the induction of pathological gene expression and cardiac remodeling. Class IIa HDACs are regulated by multiple, functionally opposing post-translational modifications, including phosphorylation by protein kinase D (PKD) that promotes nuclear export and phosphorylation by protein kinase A (PKA) that promotes nuclear import. We have previously shown that the scaffold protein muscle A-kinase anchoring protein β (mAKAPβ) orchestrates signaling in the cardiac myocyte required for pathological cardiac remodeling, including serving as a scaffold for both PKD and PKA. We now show that mAKAPβ is a scaffold for HDAC5 in cardiac myocytes, forming signalosomes containing HDAC5, PKD, and PKA. Inhibition of mAKAPβ expression attenuated the phosphorylation of HDAC5 by PKD and PKA in response to α- and β-adrenergic receptor stimulation, respectively. Importantly, disruption of mAKAPβ-HDAC5 anchoring prevented the induction of HDAC5 nuclear export by α-adrenergic receptor signaling and PKD phosphorylation. In addition, disruption of mAKAPβ-PKA anchoring prevented the inhibition by β-adrenergic receptor stimulation of α-adrenergic-induced HDAC5 nuclear export. Together, these data establish that mAKAPβ signalosomes serve to bidirectionally regulate the nuclear-cytoplasmic localization of class IIa HDACs. Thus, the mAKAPβ scaffold serves as a node in the myocyte regulatory network controlling both the repression and activation of pathological gene expression in health and disease, respectively.
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Affiliation(s)
- Kimberly L Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Cardiac Signal Transduction and Cellular Biology Laboratory, Farmington, CT, USA.
| | - Moriah Gildart
- Calhoun Center for Cardiology, University of Connecticut Health Center, Cardiac Signal Transduction and Cellular Biology Laboratory, Farmington, CT, USA
| | - Jinliang Li
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute Stanford University, Palo Alto, CA, USA
| | - Hrishikesh Thakur
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute Stanford University, Palo Alto, CA, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute Stanford University, Palo Alto, CA, USA.
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29
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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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30
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Wild AR, Dell'Acqua ML. Potential for therapeutic targeting of AKAP signaling complexes in nervous system disorders. Pharmacol Ther 2017; 185:99-121. [PMID: 29262295 DOI: 10.1016/j.pharmthera.2017.12.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A common feature of neurological and neuropsychiatric disorders is a breakdown in the integrity of intracellular signal transduction pathways. Dysregulation of ion channels and receptors in the cell membrane and the enzymatic mediators that link them to intracellular effectors can lead to synaptic dysfunction and neuronal death. However, therapeutic targeting of these ubiquitous signaling elements can lead to off-target side effects due to their widespread expression in multiple systems of the body. A-kinase anchoring proteins (AKAPs) are multivalent scaffolding proteins that compartmentalize a diverse range of receptor and effector proteins to streamline signaling within nanodomain signalosomes. A number of essential neurological processes are known to critically depend on AKAP-directed signaling and an understanding of the role AKAPs play in nervous system disorders has emerged in recent years. Selective targeting of AKAP protein-protein interactions may be a means to uncouple pathologically active signaling pathways in neurological disorders with a greater degree of specificity. In this review we will discuss the role of AKAPs in both regulating normal nervous system function and dysfunction associated with disease, and the potential for therapeutic targeting of AKAP signaling complexes.
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Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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31
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Brand T, Schindler R. New kids on the block: The Popeye domain containing (POPDC) protein family acting as a novel class of cAMP effector proteins in striated muscle. Cell Signal 2017; 40:156-165. [PMID: 28939104 PMCID: PMC6562197 DOI: 10.1016/j.cellsig.2017.09.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 01/16/2023]
Abstract
The cyclic 3′,5′-adenosine monophosphate (cAMP) signalling pathway constitutes an ancient signal transduction pathway present in prokaryotes and eukaryotes. Previously, it was thought that in eukaryotes three effector proteins mediate cAMP signalling, namely protein kinase A (PKA), exchange factor directly activated by cAMP (EPAC) and the cyclic-nucleotide gated channels. However, recently a novel family of cAMP effector proteins emerged and was termed the Popeye domain containing (POPDC) family, which consists of three members POPDC1, POPDC2 and POPDC3. POPDC proteins are transmembrane proteins, which are abundantly present in striated and smooth muscle cells. POPDC proteins bind cAMP with high affinity comparable to PKA. Presently, their biochemical activity is poorly understood. However, mutational analysis in animal models as well as the disease phenotype observed in patients carrying missense mutations suggests that POPDC proteins are acting by modulating membrane trafficking of interacting proteins. In this review, we will describe the current knowledge about this gene family and also outline the apparent gaps in our understanding of their role in cAMP signalling and beyond. Popeye domain containing (POPDC) proteins are novel class of cAMP effector proteins. POPDC proteins control membrane trafficking of interacting proteins. POPDC proteins play a role in cardiac pacemaking and atrioventricular conduction. Mutations of POPDC genes are causing muscular dystrophy.
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Affiliation(s)
- Thomas Brand
- Developmental Dynamics, Myocardial Function, National Heart and Lung Institute, Imperial College London, United Kingdom.
| | - Roland Schindler
- Developmental Dynamics, Myocardial Function, National Heart and Lung Institute, Imperial College London, United Kingdom
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32
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Abstract
The universal second messengers cyclic nucleotides 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) play central roles in cardiovascular function and disease. They act in discrete, functionally relevant subcellular microdomains which regulate, for example, calcium cycling and excitation-contraction coupling. Such localized cAMP and cGMP signals have been difficult to measure using conventional biochemical techniques. Recent years have witnessed the advent of live cell imaging techniques which allow visualization of these functionally relevant second messengers with unprecedented spatial and temporal resolution at cellular, subcellular and tissue levels. In this review, we discuss these new imaging techniques and give examples how they are used to visualize cAMP and cGMP in physiological and pathological settings to better understand cardiovascular function and disease. Two primary techniques include the use of Förster resonance energy transfer (FRET) based cyclic nucleotide biosensors and nanoscale scanning ion conductance microscopy (SICM). These methods can provide deep mechanistic insights into compartmentalized cAMP and cGMP signaling.
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Affiliation(s)
- Filip Berisha
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of General and Interventional Cardiology, University Heart Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Germany.
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33
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Parra V, Rothermel BA. Calcineurin signaling in the heart: The importance of time and place. J Mol Cell Cardiol 2017; 103:121-136. [PMID: 28007541 PMCID: PMC5778886 DOI: 10.1016/j.yjmcc.2016.12.006] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 12/12/2016] [Accepted: 12/16/2016] [Indexed: 12/20/2022]
Abstract
The calcium-activated protein phosphatase, calcineurin, lies at the intersection of protein phosphorylation and calcium signaling cascades, where it provides an essential nodal point for coordination between these two fundamental modes of intracellular communication. In excitatory cells, such as neurons and cardiomyocytes, that experience rapid and frequent changes in cytoplasmic calcium, calcineurin protein levels are exceptionally high, suggesting that these cells require high levels of calcineurin activity. Yet, it is widely recognized that excessive activation of calcineurin in the heart contributes to pathological hypertrophic remodeling and the progression to failure. How does a calcium activated enzyme function in the calcium-rich environment of the continuously contracting heart without pathological consequences? This review will discuss the wide range of calcineurin substrates relevant to cardiovascular health and the mechanisms calcineurin uses to find and act on appropriate substrates in the appropriate location while potentially avoiding others. Fundamental differences in calcineurin signaling in neonatal verses adult cardiomyocytes will be addressed as well as the importance of maintaining heterogeneity in calcineurin activity across the myocardium. Finally, we will discuss how circadian oscillations in calcineurin activity may facilitate integration with other essential but conflicting processes, allowing a healthy heart to reap the benefits of calcineurin signaling while avoiding the detrimental consequences of sustained calcineurin activity that can culminate in heart failure.
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Affiliation(s)
- Valentina Parra
- Advanced Centre for Chronic Disease (ACCDiS), Facultad Ciencias Quimicas y Farmaceuticas, Universidad de Chile, Santiago,Chile; Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Quimicas y Farmaceuticas, Universidad de Chie, Santiago, Chile
| | - Beverly A Rothermel
- Department of Internal Medicine (Cardiology Division), University of Texas Southwestern Medical Centre, Dallas, TX, USA; Department of Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
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34
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Li L, Li J, Drum BM, Chen Y, Yin H, Guo X, Luckey SW, Gilbert ML, McKnight GS, Scott JD, Santana LF, Liu Q. Loss of AKAP150 promotes pathological remodelling and heart failure propensity by disrupting calcium cycling and contractile reserve. Cardiovasc Res 2016; 113:147-159. [PMID: 27856611 DOI: 10.1093/cvr/cvw221] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/15/2016] [Accepted: 10/11/2016] [Indexed: 01/18/2023] Open
Abstract
AIMS Impaired Ca2 + cycling and myocyte contractility are a hallmark of heart failure triggered by pathological stress such as hemodynamic overload. The A-Kinase anchoring protein AKAP150 has been shown to coordinate key aspects of adrenergic regulation of Ca2+ cycling and excitation-contraction in cardiomyocytes. However, the role of the AKAP150 signalling complexes in the pathogenesis of heart failure has not been investigated. METHODS AND RESULTS Here we examined how AKAP150 signalling complexes impact Ca2+ cycling, myocyte contractility, and heart failure susceptibility following pathological stress. We detected a significant reduction of AKAP150 expression in the failing mouse heart induced by pressure overload. Importantly, cardiac-specific AKAP150 knockout mice were predisposed to develop dilated cardiomyopathy with severe cardiac dysfunction and fibrosis after pressure overload. Loss of AKAP150 also promoted pathological remodelling and heart failure progression following myocardial infarction. However, ablation of AKAP150 did not affect calcineurin-nuclear factor of activated T cells signalling in cardiomyocytes or pressure overload- or agonist-induced cardiac hypertrophy. Immunoprecipitation studies showed that AKAP150 was associated with SERCA2, phospholamban, and ryanodine receptor-2, providing a targeted control of sarcoplasmic reticulum Ca2+ regulatory proteins. Mechanistically, loss of AKAP150 led to impaired Ca2+ cycling and reduced myocyte contractility reserve following adrenergic stimulation or pressure overload. CONCLUSIONS These findings define a critical role for AKAP150 in regulating Ca2+ cycling and myocardial ionotropy following pathological stress, suggesting the AKAP150 signalling pathway may serve as a novel therapeutic target for heart failure.
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Affiliation(s)
- Lei Li
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Jing Li
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Benjamin M Drum
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Yi Chen
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Haifeng Yin
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Xiaoyun Guo
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Stephen W Luckey
- Department of Biology, Seattle University, 901 12th Ave., Seattle, WA 98122, USA
| | - Merle L Gilbert
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - G Stanley McKnight
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - John D Scott
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA.,Howard Hughes Medical Institute, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - L Fernando Santana
- Deparment of Physiology & Membrane Biology, University of California, One Shields Ave., Davis, CA 95616, USA
| | - Qinghang Liu
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA;
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35
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Terentyev D, Hamilton S. Regulation of sarcoplasmic reticulum Ca 2+ release by serine-threonine phosphatases in the heart. J Mol Cell Cardiol 2016; 101:156-164. [PMID: 27585747 DOI: 10.1016/j.yjmcc.2016.08.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 12/17/2022]
Abstract
The amount and timing of Ca2+ release from the sarcoplasmic reticulum (SR) during cardiac cycle are the main determinants of cardiac contractility. Reversible phosphorylation of the SR Ca2+ release channel, ryanodine receptor type 2 (RyR2) is the central mechanism of regulation of Ca2+ release in cardiomyocytes. Three major serine-threonine phosphatases including PP1, PP2A and PP2B (calcineurin) have been implicated in modulation of RyR2 function. Changes in expression levels of these phosphatases, their activity and targeting to the RyR2 macromolecular complex were demonstrated in many animal models of cardiac disease and humans and are implicated in cardiac arrhythmia and heart failure. Here we review evidence in support of regulation of RyR2-mediated SR Ca2+ release by serine-threonine phosphatases and the role and mechanisms of dysregulation of phosphatases in various disease states.
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Affiliation(s)
- Dmitry Terentyev
- The Warren Alpert Medical School of Brown University, Rhode Island Hospital, Department of Medicine, Cardiovascular Research Center, United States.
| | - Shanna Hamilton
- Cardiff University, School of Medicine, Wales Heart Research Institute, United Kingdom
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36
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Abstract
Cardiac remodeling is regulated by an extensive intracellular signal transduction network. Each of the many signaling pathways in this network contributes uniquely to the control of cellular adaptation. In the last few years, it has become apparent that multimolecular signaling complexes or "signalosomes" are important for fidelity in intracellular signaling and for mediating crosstalk between the different signaling pathways. These complexes integrate upstream signals and control downstream effectors. In the cardiac myocyte, the protein mAKAPβ serves as a scaffold for a large signalosome that is responsive to cAMP, calcium, hypoxia, and mitogen-activated protein kinase signaling. The main function of mAKAPβ signalosomes is to modulate stress-related gene expression regulated by the transcription factors NFATc, MEF2, and HIF-1α and type II histone deacetylases that control pathological cardiac hypertrophy.
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37
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Smrcka AV. Regulation of phosphatidylinositol-specific phospholipase C at the nuclear envelope in cardiac myocytes. J Cardiovasc Pharmacol 2016; 65:203-10. [PMID: 25658460 DOI: 10.1097/fjc.0000000000000195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Phosphatidylinositol 4,5-bisphosphate hydrolysis at the plasma membrane by phospholipase C is one of the major hormone regulated intracellular signaling systems. The system generates the diffusible second messenger IP3 and the membrane bound messenger diacylglycerol. Spatial regulation of this system has been thought to be through specific subcellular distributions of the IP3 receptor or PKC. As is becoming increasingly apparent, receptor-stimulated signaling systems are also found at intracellular membranes. As discussed in this issue, G protein-coupled receptors have been identified at the nuclear envelope implying intracellular localization of the signaling systems that respond to G protein-coupled receptors. Here, we discuss the evidence for the existence of PLC signals that regulate nuclear processes, as well as the evidence for nuclear and nuclear envelope localization of PLC signaling components, and their implications for cardiac physiology and disease.
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Affiliation(s)
- Alan V Smrcka
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
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38
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Araujo CM, Hermidorff MM, Amancio GDCS, Lemos DDS, Silva ME, de Assis LVM, Isoldi MC. Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor? J Recept Signal Transduct Res 2015; 36:435-44. [PMID: 27305962 DOI: 10.3109/10799893.2015.1122042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.
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Affiliation(s)
- Carolina Morais Araujo
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Milla Marques Hermidorff
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Gabriela de Cassia Sousa Amancio
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Denise da Silveira Lemos
- b Laboratory of Immunoparasitology , Center for Research in Biological Sciences, Institute of Biological and Exact Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Marcelo Estáquio Silva
- c Laboratory of Experimental Nutrition , School of Nutrition, Federal University of Ouro Preto , Ouro Preto , Brazil , and
| | | | - Mauro César Isoldi
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
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Diviani D, Reggi E, Arambasic M, Caso S, Maric D. Emerging roles of A-kinase anchoring proteins in cardiovascular pathophysiology. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1926-36. [PMID: 26643253 DOI: 10.1016/j.bbamcr.2015.11.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 01/08/2023]
Abstract
Heart and blood vessels ensure adequate perfusion of peripheral organs with blood and nutrients. Alteration of the homeostatic functions of the cardiovascular system can cause hypertension, atherosclerosis, and coronary artery disease leading to heart injury and failure. A-kinase anchoring proteins (AKAPs) constitute a family of scaffolding proteins that are crucially involved in modulating the function of the cardiovascular system both under physiological and pathological conditions. AKAPs assemble multifunctional signaling complexes that ensure correct targeting of the cAMP-dependent protein kinase (PKA) as well as other signaling enzymes to precise subcellular compartments. This allows local regulation of specific effector proteins that control the function of vascular and cardiac cells. This review will focus on recent advances illustrating the role of AKAPs in cardiovascular pathophysiology. The accent will be mainly placed on the molecular events linked to the control of vascular integrity and blood pressure as well as on the cardiac remodeling process associated with heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Dario Diviani
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland.
| | - Erica Reggi
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Miroslav Arambasic
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Stefania Caso
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
| | - Darko Maric
- Département de Pharmacologie et de Toxicologie, Faculté de Biologie et de Médecine, Lausanne 1005, Switzerland
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Lee SW, Won JY, Yang J, Lee J, Kim SY, Lee EJ, Kim HS. AKAP6 inhibition impairs myoblast differentiation and muscle regeneration: Positive loop between AKAP6 and myogenin. Sci Rep 2015; 5:16523. [PMID: 26563778 PMCID: PMC4643297 DOI: 10.1038/srep16523] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/13/2015] [Indexed: 01/27/2023] Open
Abstract
Skeletal muscle regeneration occurs continuously to repair muscle damage incurred during normal activity and in chronic disease or injury. Herein, we report that A-kinase anchoring protein 6 (AKAP6) is important for skeletal myoblast differentiation and muscle regeneration. Compared with unstimulated skeletal myoblasts that underwent proliferation, differentiated cells show significant stimulation of AKAP6 expression. AKAP6 knockdown with siRNA effectively halts the formation of myotubes and decreases the expression of the differentiation markers myogenin and myosin heavy chain. When shAKAP6-lentivirus is delivered to mice with cardiotoxin (CTX)-induced muscle injury, muscle regeneration is impaired compared with that of mice injected with control shMock-lentivirus. The motor functions of mice infected with shAKAP6-lentivirus (CTX+shAK6) are significantly worse than those of mice infected with shMock-lentivirus (CTX+shMock). Mechanistic analysis showed that AKAP6 promotes myogenin expression through myocyte enhancer factor 2A (MEF2A). Notably, myogenin increases AKAP6 expression as well. The results of chromatin immunoprecipitation and luciferase assays showed that myogenin binds to an E-box site on the AKAP6 promoter. Taken together, our findings demonstrate a novel interplay between AKAP6 and myogenin, and we suggest that AKAP6 is an important regulator of myoblast differentiation, myotube formation, and muscle regeneration.
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Affiliation(s)
- Sae-Won Lee
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Joo-Yun Won
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Jimin Yang
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Jaewon Lee
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Su-Yeon Kim
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Eun Ju Lee
- Biomedical Research Institute and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea
| | - Hyo-Soo Kim
- Department of Internal Medicine and IRICT, Seoul National University Hospital, 101 DaeHak-ro, JongRo-gu Seoul, 110-744, Republic of Korea.,Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Korea
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41
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Weber S, Meyer-Roxlau S, Wagner M, Dobrev D, El-Armouche A. Counteracting Protein Kinase Activity in the Heart: The Multiple Roles of Protein Phosphatases. Front Pharmacol 2015; 6:270. [PMID: 26617522 PMCID: PMC4643138 DOI: 10.3389/fphar.2015.00270] [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: 08/24/2015] [Accepted: 10/28/2015] [Indexed: 12/19/2022] Open
Abstract
Decades of cardiovascular research have shown that variable and flexible levels of protein phosphorylation are necessary to maintain cardiac function. A delicate balance between phosphorylated and dephosphorylated states of proteins is guaranteed by a complex interplay of protein kinases (PKs) and phosphatases. Serine/threonine phosphatases, in particular members of the protein phosphatase (PP) family govern dephosphorylation of the majority of these cardiac proteins. Recent findings have however shown that PPs do not only dephosphorylate previously phosphorylated proteins as a passive control mechanism but are capable to actively control PK activity via different direct and indirect signaling pathways. These control mechanisms can take place on (epi-)genetic, (post-)transcriptional, and (post-)translational levels. In addition PPs themselves are targets of a plethora of proteinaceous interaction partner regulating their endogenous activity, thus adding another level of complexity and feedback control toward this system. Finally, novel approaches are underway to achieve spatiotemporal pharmacologic control of PPs which in turn can be used to fine-tune misleaded PK activity in heart disease. Taken together, this review comprehensively summarizes the major aspects of PP-mediated PK regulation and discusses the subsequent consequences of deregulated PP activity for cardiovascular diseases in depth.
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Affiliation(s)
- Silvio Weber
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Stefanie Meyer-Roxlau
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Michael Wagner
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, Faculty of Medicine, West German Heart and Vascular Center , Essen, Germany
| | - Ali El-Armouche
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
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42
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Dema A, Perets E, Schulz MS, Deák VA, Klussmann E. Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling. Cell Signal 2015; 27:2474-87. [PMID: 26386412 DOI: 10.1016/j.cellsig.2015.09.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/14/2015] [Indexed: 01/26/2023]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.
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Affiliation(s)
- Alessandro Dema
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Ekaterina Perets
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Maike Svenja Schulz
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Veronika Anita Deák
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany; DZHK, German Centre for Cardiovascular Research, Oudenarder Straße 16, 13347 Berlin, Germany.
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43
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Calejo AI, Taskén K. Targeting protein-protein interactions in complexes organized by A kinase anchoring proteins. Front Pharmacol 2015; 6:192. [PMID: 26441649 PMCID: PMC4562273 DOI: 10.3389/fphar.2015.00192] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/24/2015] [Indexed: 01/06/2023] Open
Abstract
Cyclic AMP is a ubiquitous intracellular second messenger involved in the regulation of a wide variety of cellular processes, a majority of which act through the cAMP – protein kinase A (PKA) signaling pathway and involve PKA phosphorylation of specific substrates. PKA phosphorylation events are typically spatially restricted and temporally well controlled. A-kinase anchoring proteins (AKAPs) directly bind PKA and recruit it to specific subcellular loci targeting the kinase activity toward particular substrates, and thereby provide discrete spatiotemporal control of downstream phosphorylation events. AKAPs also scaffold other signaling molecules into multi-protein complexes that function as crossroads between different signaling pathways. Targeting AKAP coordinated protein complexes with high-affinity peptidomimetics or small molecules to tease apart distinct protein–protein interactions (PPIs) therefore offers important means to disrupt binding of specific components of the complex to better understand the molecular mechanisms involved in the function of individual signalosomes and their pathophysiological role. Furthermore, development of novel classes of small molecules involved in displacement of AKAP-bound signal molecules is now emerging. Here, we will focus on mechanisms for targeting PPI, disruptors that modulate downstream cAMP signaling and their role, especially in the heart.
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Affiliation(s)
- Ana I Calejo
- Biotechnology Centre, University of Oslo Oslo, Norway ; Centre for Molecular Medicine Norway, Nordic European Molecular Biology Laboratory Partnership, University of Oslo and Oslo University Hospital Oslo, Norway
| | - Kjetil Taskén
- Biotechnology Centre, University of Oslo Oslo, Norway ; Centre for Molecular Medicine Norway, Nordic European Molecular Biology Laboratory Partnership, University of Oslo and Oslo University Hospital Oslo, Norway
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44
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Guo H, Liu B, Hou L, The E, Li G, Wang D, Jie Q, Che W, Wei Y. The role of mAKAPβ in the process of cardiomyocyte hypertrophy induced by angiotensin II. Int J Mol Med 2015; 35:1159-68. [PMID: 25739102 PMCID: PMC4380120 DOI: 10.3892/ijmm.2015.2119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/04/2015] [Indexed: 12/16/2022] Open
Abstract
Angiotensin II (AngII) is the central product of the renin-angiotensin system (RAS) and this octapeptide contributes to the pathophysiology of cardiac hypertrophy and remodeling. mAKAPβ is an A-kinase anchoring protein (AKAP) that has the function of binding to the regulatory subunit of protein kinase A (PKA) and confining the holoenzyme to discrete locations within the cell. In this study, we aimed to investigate the role of mAKAPβ in AngII‑induced cardiomyocyte hypertrophy and the possible mechanisms involved. Cultured cardiomyocytes from neonatal rats were treated with AngII. Subsequently, the morphology of the cardiomyocytes was observed and the expression of mAKAPβ and cardiomyocyte hypertrophic markers was measured. mAKAPβ‑shRNA was constructed for RNA interference; the expression of mAKAPβ and hypertrophic markers, the cell surface area and the [3H]Leucine incorporation rate in the AngII‑treated rat cardiomyocytes were detected following RNA interference. Simultaneously, changes in the expression levels of phosphorylated extracellular signal-regulated kinase (p-ERK)2 in the cardiomyocytes were assessed. The cell size of the AngII-treated cardiaomyocytes was significantly larger than that of the untreated cardiomyocytes. The expression of hypertrophic markers and p-ERK2, the cell surface area and the [3H]Leucine incorporation rate were all significantly increased in the AngII‑treated cells. However, the expression of mAKAPβ remained unaltered in this process. RNA interference simultaneously inhibited the protein expression of mAKAPβ and p‑ERK2, and the hypertrophy of the cardiomyocytes induced by AngII was attenuated. These results demonstrate that AngII induces hypertrophy in cardiomyocytes, and mAKAPβ is possibly involved in this process. The effects of mAKAPβ on AngII‑induced cardiomyocyte hypertrophy may be associated with p-ERK2 expression.
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Affiliation(s)
- Huixin Guo
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Baoxin Liu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Lei Hou
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Erlinda The
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Gang Li
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Dongzhi Wang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Qiqiang Jie
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Wenliang Che
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Yidong Wei
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
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45
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Wang L, Burmeister BT, Johnson KR, Baillie GS, Karginov AV, Skidgel RA, O'Bryan JP, Carnegie GK. UCR1C is a novel activator of phosphodiesterase 4 (PDE4) long isoforms and attenuates cardiomyocyte hypertrophy. Cell Signal 2015; 27:908-22. [PMID: 25683917 DOI: 10.1016/j.cellsig.2015.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 01/21/2023]
Abstract
Hypertrophy increases the risk of heart failure and arrhythmia. Prevention or reversal of the maladaptive hypertrophic phenotype has thus been proposed to treat heart failure. Chronic β-adrenergic receptor (β-AR) stimulation induces cardiomyocyte hypertrophy by elevating 3',5'-cyclic adenosine monophosphate (cAMP) levels and activating downstream effectors such protein kinase A (PKA). Conversely, hydrolysis of cAMP by phosphodiesterases (PDEs) spatiotemporally restricts cAMP signaling. Here, we demonstrate that PDE4, but not PDE3, is critical in regulating cardiomyocyte hypertrophy, and may represent a potential target for preventing maladaptive hypertrophy. We identify a sequence within the upstream conserved region 1 of PDE4D, termed UCR1C, as a novel activator of PDE4 long isoforms. UCR1C activates PDE4 in complex with A-kinase anchoring protein (AKAP)-Lbc resulting in decreased PKA signaling facilitated by AKAP-Lbc. Expression of UCR1C in cardiomyocytes inhibits hypertrophy in response to chronic β-AR stimulation. This effect is partially due to inhibition of nuclear PKA activity, which decreases phosphorylation of the transcription factor cAMP response element-binding protein (CREB). In conclusion, PDE4 activation by UCR1C attenuates cardiomyocyte hypertrophy by specifically inhibiting nuclear PKA activity.
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Affiliation(s)
- Li Wang
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
| | - Brian T Burmeister
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
| | - Keven R Johnson
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
| | - George S Baillie
- Institute of Cardiovascular and Medical Science, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G128QQ, Scotland, United Kingdom
| | - Andrei V Karginov
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA; University of Illinois Cancer Center, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
| | - Randal A Skidgel
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
| | - John P O'Bryan
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA; University of Illinois Cancer Center, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA; Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA; Jessie Brown VA Medical Center, 820 S Damen Ave, Chicago, IL 60612, USA.
| | - Graeme K Carnegie
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, E403 MSB, 835 South Wolcott Avenue, Chicago, IL 60612, USA
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46
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Compartmentalization role of A-kinase anchoring proteins (AKAPs) in mediating protein kinase A (PKA) signaling and cardiomyocyte hypertrophy. Int J Mol Sci 2014. [PMID: 25547489 DOI: 10.3390/ijms16010218.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The Beta-adrenergic receptors (β-ARs) stimulation enhances contractility through protein kinase-A (PKA) substrate phosphorylation. This PKA signaling is conferred in part by PKA binding to A-kinase anchoring proteins (AKAPs). AKAPs coordinate multi-protein signaling networks that are targeted to specific intracellular locations, resulting in the localization of enzyme activity and transmitting intracellular actions of neurotransmitters and hormones to its target substrates. In particular, mAKAP (muscle-selective AKAP) has been shown to be present on the nuclear envelope of cardiomyocytes with various proteins including: PKA-regulatory subunit (RIIα), phosphodiesterase-4D3, protein phosphatase-2A, and ryanodine receptor (RyR2). Therefore, through the coordination of spatial-temporal signaling of proteins and enzymes, mAKAP controls cyclic-adenosine monophosphate (cAMP) levels very tightly and functions as a regulator of PKA-mediated substrate phosphorylation leading to changes in calcium availability and myofilament calcium sensitivity. The goal of this review is to elucidate the critical compartmentalization role of mAKAP in mediating PKA signaling and regulating cardiomyocyte hypertrophy by acting as a scaffolding protein. Based on our literature search and studying the structure-function relationship between AKAP scaffolding protein and its binding partners, we propose possible explanations for the mechanism by which mAKAP promotes cardiac hypertrophy.
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47
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Rababa'h A, Singh S, Suryavanshi SV, Altarabsheh SE, Deo SV, McConnell BK. Compartmentalization role of A-kinase anchoring proteins (AKAPs) in mediating protein kinase A (PKA) signaling and cardiomyocyte hypertrophy. Int J Mol Sci 2014; 16:218-29. [PMID: 25547489 PMCID: PMC4307244 DOI: 10.3390/ijms16010218] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/18/2014] [Indexed: 02/07/2023] Open
Abstract
The Beta-adrenergic receptors (β-ARs) stimulation enhances contractility through protein kinase-A (PKA) substrate phosphorylation. This PKA signaling is conferred in part by PKA binding to A-kinase anchoring proteins (AKAPs). AKAPs coordinate multi-protein signaling networks that are targeted to specific intracellular locations, resulting in the localization of enzyme activity and transmitting intracellular actions of neurotransmitters and hormones to its target substrates. In particular, mAKAP (muscle-selective AKAP) has been shown to be present on the nuclear envelope of cardiomyocytes with various proteins including: PKA-regulatory subunit (RIIα), phosphodiesterase-4D3, protein phosphatase-2A, and ryanodine receptor (RyR2). Therefore, through the coordination of spatial-temporal signaling of proteins and enzymes, mAKAP controls cyclic-adenosine monophosphate (cAMP) levels very tightly and functions as a regulator of PKA-mediated substrate phosphorylation leading to changes in calcium availability and myofilament calcium sensitivity. The goal of this review is to elucidate the critical compartmentalization role of mAKAP in mediating PKA signaling and regulating cardiomyocyte hypertrophy by acting as a scaffolding protein. Based on our literature search and studying the structure-function relationship between AKAP scaffolding protein and its binding partners, we propose possible explanations for the mechanism by which mAKAP promotes cardiac hypertrophy.
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Affiliation(s)
- Abeer Rababa'h
- Department of Clinical Pharmacy, Jordan University of Science and Technology, Irbid 22110, Jordan.
| | - Sonal Singh
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Texas Medical Center, Houston, TX 77204, USA.
| | - Santosh V Suryavanshi
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Texas Medical Center, Houston, TX 77204, USA.
| | | | - Salil V Deo
- Department of Cardiovascular Surgery, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Bradley K McConnell
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Texas Medical Center, Houston, TX 77204, USA.
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Li X, Matta SM, Sullivan RD, Bahouth SW. Carvedilol reverses cardiac insufficiency in AKAP5 knockout mice by normalizing the activities of calcineurin and CaMKII. Cardiovasc Res 2014; 104:270-9. [PMID: 25225170 DOI: 10.1093/cvr/cvu209] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
AIMS Cardiac β-adrenergic receptors (β-AR) are key regulators of cardiac haemodynamics and size. The scaffolding protein A-kinase anchoring protein 79/150 (AKAP5) is a key regulator of myocardial signalling by β-ARs. We examined the function of AKAP5 in regulating cardiac haemodynamics and size, and the role of β-ARs and Ca(2+)-regulated intracellular signalling pathways in this phenomenon. METHODS AND RESULTS We used echocardiographic, histological, genetic, and biochemical methods to examine the effect of ablation of AKAP5 on cardiac haemodynamics, size, and signalling in mice. AKAP5(-/-) mice exhibited enhanced signs of cardiac dilatation and dysfunction that progressed with age. Infusions of isoprenaline worsened cardiac haemodynamics in wild-type (WT) mice only, but increased the ratio of heart-to-body weight equally in WT and in AKAP5(-/-) mice. Mechanistically, loss of AKAP5 was associated with enhanced activity of cardiac calmodulin kinase II (CaMKII) and calcineurin (CaN) as indexed by nuclear factor of activated T-cell-luciferase activity. Loss of AKAP5 interfered with the recycling of cardiac β1-ARs, which was mediated in part by CaN binding to AKAP5. Carvedilol reversed cardiac hypertrophy and haemodynamic deficiencies in AKAP5(-/-) mice by normalizing the activities of cardiac CaN and CaMKII. CONCLUSIONS These findings identify a novel cardioprotective role for AKAP5 that is mediated by regulating the activities of cardiac CaN and CaMKII and highlight a significant role for cardiac β-ARs in this phenomenon.
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Affiliation(s)
- Xin Li
- Department of Pharmacology, The University of Tennessee Health Sciences Center, 874 Union Avenue, Memphis, TN 38163, USA
| | - Shannon M Matta
- Department of Pharmacology, The University of Tennessee Health Sciences Center, 874 Union Avenue, Memphis, TN 38163, USA
| | - Ryan D Sullivan
- Department of Comparative Medicine, The University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Suleiman W Bahouth
- Department of Pharmacology, The University of Tennessee Health Sciences Center, 874 Union Avenue, Memphis, TN 38163, USA
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Soni S, Scholten A, Vos MA, van Veen TAB. Anchored protein kinase A signalling in cardiac cellular electrophysiology. J Cell Mol Med 2014; 18:2135-46. [PMID: 25216213 PMCID: PMC4224547 DOI: 10.1111/jcmm.12365] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/10/2014] [Indexed: 01/13/2023] Open
Abstract
The cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) is an elementary molecule involved in both acute and chronic modulation of cardiac function. Substantial research in recent years has highlighted the importance of A-kinase anchoring proteins (AKAP) therein as they act as the backbones of major macromolecular signalling complexes of the β-adrenergic/cAMP/PKA pathway. This review discusses the role of AKAP-associated protein complexes in acute and chronic cardiac modulation by dissecting their role in altering the activity of different ion channels, which underlie cardiac action potential (AP) generation. In addition, we review the involvement of different AKAP complexes in mechanisms of cardiac remodelling and arrhythmias.
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Affiliation(s)
- Siddarth Soni
- Division of Heart & Lungs, Dept of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands; Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
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50
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Kapiloff MS, Rigatti M, Dodge-Kafka KL. Architectural and functional roles of A kinase-anchoring proteins in cAMP microdomains. ACTA ACUST UNITED AC 2014; 143:9-15. [PMID: 24378903 PMCID: PMC3874566 DOI: 10.1085/jgp.201311020] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Michael S Kapiloff
- Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, 2 Department of Pediatrics, and 3 Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33101
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