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Zhu Y, Nair RV, Xia X, Nahmou M, Li X, Yan W, Li J, Tanasa B, Goldberg JL, Kapiloff MS. Reversal of injury-associated retinal ganglion cell gene expression by a phosphodiesterase anchoring disruptor peptide. Exp Eye Res 2024; 246:110017. [PMID: 39097072 PMCID: PMC11330710 DOI: 10.1016/j.exer.2024.110017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 06/24/2024] [Accepted: 07/31/2024] [Indexed: 08/05/2024]
Abstract
Loss of retinal ganglion cells (RGCs) is central to the pathogenesis of optic neuropathies such as glaucoma. Increased RGC cAMP signaling is neuroprotective. We have shown that displacement of the cAMP-specific phosphodiesterase PDE4D3 from an RGC perinuclear compartment by expression of the modified PDE4D3 N-terminal peptide 4D3(E) increases perinuclear cAMP and protein kinase A activity in cultured neurons and in vivo RGC survival after optic nerve crush (ONC) injury. To explore mechanisms by which PDE4D3 displacement promotes neuroprotection, in this study mice intravitreally injected with an adeno-associated virus to express an mCherry-tagged 4D3(E) peptide were subjected to ONC injury and analyzed by single cell RNA-sequencing (scRNA-seq). 4D3(E)-mCherry expression was associated with an attenuation of injury-induced changes in gene expression, thereby supporting the hypothesis that enhanced perinuclear PKA signaling promotes neuroprotective RGC gene expression.
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Affiliation(s)
- Ying Zhu
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Ramesh V Nair
- Stanford Center for Genomics and Personalized Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Xin Xia
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Michael Nahmou
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Xueyi Li
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Wenjun Yan
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Jinliang Li
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Bogdan Tanasa
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA
| | - Michael S Kapiloff
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA, 94034, USA.
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2
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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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3
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He Z, Xie L, Liu J, Wei X, Zhang W, Mei Z. Novel insight into the role of A-kinase anchoring proteins (AKAPs) in ischemic stroke and therapeutic potentials. Biomed Pharmacother 2024; 175:116715. [PMID: 38739993 DOI: 10.1016/j.biopha.2024.116715] [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: 02/25/2024] [Revised: 05/03/2024] [Accepted: 05/06/2024] [Indexed: 05/16/2024] Open
Abstract
Ischemic stroke, a devastating disease associated with high mortality and disability worldwide, has emerged as an urgent public health issue. A-kinase anchoring proteins (AKAPs) are a group of signal-organizing molecules that compartmentalize and anchor a wide range of receptors and effector proteins and have a major role in stabilizing mitochondrial function and promoting neurodevelopmental development in the central nervous system (CNS). Growing evidence suggests that dysregulation of AKAPs expression and activity is closely associated with oxidative stress, ion disorder, mitochondrial dysfunction, and blood-brain barrier (BBB) impairment in ischemic stroke. However, the underlying mechanisms remain inadequately understood. This review provides a comprehensive overview of the composition and structure of A-kinase anchoring protein (AKAP) family members, emphasizing their physiological functions in the CNS. We explored in depth the molecular and cellular mechanisms of AKAP complexes in the pathological progression and risk factors of ischemic stroke, including hypertension, hyperglycemia, lipid metabolism disorders, and atrial fibrillation. Herein, we highlight the potential of AKAP complexes as a pharmacological target against ischemic stroke in the hope of inspiring translational research and innovative clinical approaches.
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Affiliation(s)
- Ziyu He
- Key Laboratory of Hunan Province for Integrated Traditional Chinese and Western Medicine on Prevention and Treatment of Cardio-Cerebral Diseases, College of Integrated Traditional Chinese Medicine and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Letian Xie
- Key Laboratory of Hunan Province for Integrated Traditional Chinese and Western Medicine on Prevention and Treatment of Cardio-Cerebral Diseases, College of Integrated Traditional Chinese Medicine and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Jiyong Liu
- Hunan Provincial Key Laboratory of Traditional Chinese Medicine Diagnostics, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Xuan Wei
- Key Laboratory of Hunan Province for Integrated Traditional Chinese and Western Medicine on Prevention and Treatment of Cardio-Cerebral Diseases, College of Integrated Traditional Chinese Medicine and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China
| | - Wenli Zhang
- School of Pharmacy, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China.
| | - Zhigang Mei
- Key Laboratory of Hunan Province for Integrated Traditional Chinese and Western Medicine on Prevention and Treatment of Cardio-Cerebral Diseases, College of Integrated Traditional Chinese Medicine and Western Medicine, Hunan University of Chinese Medicine, Changsha, Hunan 410208, China; Third-Grade Pharmacological Laboratory on Chinese Medicine Approved by State Administration of Traditional Chinese Medicine, College of Medicine and Health Sciences, China Three Gorges University, Yichang, Hubei 443002, China.
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4
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Wei J, Duan X, Chen J, Zhang D, Xu J, Zhuang J, Wang S. Metabolic adaptations in pressure overload hypertrophic heart. Heart Fail Rev 2024; 29:95-111. [PMID: 37768435 DOI: 10.1007/s10741-023-10353-y] [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] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
This review article offers a detailed examination of metabolic adaptations in pressure overload hypertrophic hearts, a condition that plays a pivotal role in the progression of heart failure with preserved ejection fraction (HFpEF) to heart failure with reduced ejection fraction (HFrEF). The paper delves into the complex interplay between various metabolic pathways, including glucose metabolism, fatty acid metabolism, branched-chain amino acid metabolism, and ketone body metabolism. In-depth insights into the shifts in substrate utilization, the role of different transporter proteins, and the potential impact of hypoxia-induced injuries are discussed. Furthermore, potential therapeutic targets and strategies that could minimize myocardial injury and promote cardiac recovery in the context of pressure overload hypertrophy (POH) are examined. This work aims to contribute to a better understanding of metabolic adaptations in POH, highlighting the need for further research on potential therapeutic applications.
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Affiliation(s)
- Jinfeng Wei
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Xuefei Duan
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jiaying Chen
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Dengwen Zhang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jindong Xu
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jian Zhuang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
| | - Sheng Wang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
- Linzhi People's Hospital, Linzhi, Tibet, China.
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5
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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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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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7
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Regulation of cardiac function by cAMP nanodomains. Biosci Rep 2023; 43:232544. [PMID: 36749130 PMCID: PMC9970827 DOI: 10.1042/bsr20220953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/29/2023] [Accepted: 02/07/2023] [Indexed: 02/08/2023] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a diffusible intracellular second messenger that plays a key role in the regulation of cardiac function. In response to the release of catecholamines from sympathetic terminals, cAMP modulates heart rate and the strength of contraction and ease of relaxation of each heartbeat. At the same time, cAMP is involved in the response to a multitude of other hormones and neurotransmitters. A sophisticated network of regulatory mechanisms controls the temporal and spatial propagation of cAMP, resulting in the generation of signaling nanodomains that enable the second messenger to match each extracellular stimulus with the appropriate cellular response. Multiple proteins contribute to this spatiotemporal regulation, including the cAMP-hydrolyzing phosphodiesterases (PDEs). By breaking down cAMP to a different extent at different locations, these enzymes generate subcellular cAMP gradients. As a result, only a subset of the downstream effectors is activated and a specific response is executed. Dysregulation of cAMP compartmentalization has been observed in cardiovascular diseases, highlighting the importance of appropriate control of local cAMP signaling. Current research is unveiling the molecular organization underpinning cAMP compartmentalization, providing original insight into the physiology of cardiac myocytes and the alteration associated with disease, with the potential to uncover novel therapeutic targets. Here, we present an overview of the mechanisms that are currently understood to be involved in generating cAMP nanodomains and we highlight the questions that remain to be answered.
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8
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Ulengin-Talkish I, Cyert MS. A cellular atlas of calcineurin signaling. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119366. [PMID: 36191737 PMCID: PMC9948804 DOI: 10.1016/j.bbamcr.2022.119366] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/25/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
Intracellular Ca2+ signals are temporally controlled and spatially restricted. Signaling occurs adjacent to sites of Ca2+ entry and/or release, where Ca2+-dependent effectors and their substrates co-localize to form signaling microdomains. Here we review signaling by calcineurin, the Ca2+/calmodulin regulated protein phosphatase and target of immunosuppressant drugs, Cyclosporin A and FK506. Although well known for its activation of the adaptive immune response via NFAT dephosphorylation, systematic mapping of human calcineurin substrates and regulators reveals unexpected roles for this versatile phosphatase throughout the cell. We discuss calcineurin function, with an emphasis on where signaling occurs and mechanisms that target calcineurin and its substrates to signaling microdomains, especially binding of cognate short linear peptide motifs (SLiMs). Calcineurin is ubiquitously expressed and regulates events at the plasma membrane, other intracellular membranes, mitochondria, the nuclear pore complex and centrosomes/cilia. Based on our expanding knowledge of localized CN actions, we describe a cellular atlas of Ca2+/calcineurin signaling.
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Affiliation(s)
| | - Martha S Cyert
- Department of Biology, Stanford University, Stanford, CA 94035, United States.
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9
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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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10
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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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Liu Y, Chen X, Zhang HG. Editorial: Cardiac Hypertrophy: From Compensation to Decompensation and Pharmacological Interventions. Front Pharmacol 2021; 12:665936. [PMID: 33981242 PMCID: PMC8107717 DOI: 10.3389/fphar.2021.665936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/13/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ya Liu
- Department of Pharmacology, Army Medical University (Third Military Medical University), Chongqing, China
| | - Xiongwen Chen
- Cardiovascular Research Center, Temple University Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Hai-Gang Zhang
- Department of Pharmacology, Army Medical University (Third Military Medical University), Chongqing, China
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12
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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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Abstract
The field of cAMP signaling is witnessing exciting developments with the recognition that cAMP is compartmentalized and that spatial regulation of cAMP is critical for faithful signal coding. This realization has changed our understanding of cAMP signaling from a model in which cAMP connects a receptor at the plasma membrane to an intracellular effector in a linear pathway to a model in which cAMP signals propagate within a complex network of alternative branches and the specific functional outcome strictly depends on local regulation of cAMP levels and on selective activation of a limited number of branches within the network. In this review, we cover some of the early studies and summarize more recent evidence supporting the model of compartmentalized cAMP signaling, and we discuss how this knowledge is starting to provide original mechanistic insight into cell physiology and a novel framework for the identification of disease mechanisms that potentially opens new avenues for therapeutic interventions. SIGNIFICANCE STATEMENT: cAMP mediates the intracellular response to multiple hormones and neurotransmitters. Signal fidelity and accurate coordination of a plethora of different cellular functions is achieved via organization of multiprotein signalosomes and cAMP compartmentalization in subcellular nanodomains. Defining the organization and regulation of subcellular cAMP nanocompartments is necessary if we want to understand the complex functional ramifications of pharmacological treatments that target G protein-coupled receptors and for generating a blueprint that can be used to develop precision medicine interventions.
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Affiliation(s)
- Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Anna Zerio
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Miguel J Lobo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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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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Schoenherr C, Byron A, Griffith B, Loftus A, Wills JC, Munro AF, von Kriegsheim A, Frame MC. The autophagy protein Ambra1 regulates gene expression by supporting novel transcriptional complexes. J Biol Chem 2020; 295:12045-12057. [PMID: 32616651 PMCID: PMC7443501 DOI: 10.1074/jbc.ra120.012565] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/24/2020] [Indexed: 12/13/2022] Open
Abstract
Ambra1 is considered an autophagy and trafficking protein with roles in neurogenesis and cancer cell invasion. Here, we report that Ambra1 also localizes to the nucleus of cancer cells, where it has a novel nuclear scaffolding function that controls gene expression. Using biochemical fractionation and proteomics, we found that Ambra1 binds to multiple classes of proteins in the nucleus, including nuclear pore proteins, adaptor proteins such as FAK and Akap8, chromatin-modifying proteins, and transcriptional regulators like Brg1 and Atf2. We identified biologically important genes, such as Angpt1, Tgfb2, Tgfb3, Itga8, and Itgb7, whose transcription is regulated by Ambra1-scaffolded complexes, likely by altering histone modifications and Atf2 activity. Therefore, in addition to its recognized roles in autophagy and trafficking, Ambra1 scaffolds protein complexes at chromatin, regulating transcriptional signaling in the nucleus. This novel function for Ambra1, and the specific genes impacted, may help to explain the wider role of Ambra1 in cancer cell biology.
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Affiliation(s)
- Christina Schoenherr
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Byron
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Billie Griffith
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alexander Loftus
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Jimi C Wills
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alison F Munro
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alex von Kriegsheim
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Margaret C Frame
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom.
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17
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Ljubojevic-Holzer S, Herren AW, Djalinac N, Voglhuber J, Morotti S, Holzer M, Wood BM, Abdellatif M, Matzer I, Sacherer M, Radulovic S, Wallner M, Ivanov M, Wagner S, Sossalla S, von Lewinski D, Pieske B, Brown JH, Sedej S, Bossuyt J, Bers DM. CaMKIIδC Drives Early Adaptive Ca 2+ Change and Late Eccentric Cardiac Hypertrophy. Circ Res 2020; 127:1159-1178. [PMID: 32821022 PMCID: PMC7547876 DOI: 10.1161/circresaha.120.316947] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Supplemental Digital Content is available in the text. CaMKII (Ca2+-Calmodulin dependent protein kinase) δC activation is implicated in pathological progression of heart failure (HF) and CaMKIIδC transgenic mice rapidly develop HF and arrhythmias. However, little is known about early spatio-temporal Ca2+ handling and CaMKII activation in hypertrophy and HF.
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Affiliation(s)
- Senka Ljubojevic-Holzer
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria.,Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.).,BioTechMed Graz, Austria (S.L.-H., J.V., S. Sedej)
| | - Anthony W Herren
- Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.)
| | - Natasa Djalinac
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Julia Voglhuber
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria.,BioTechMed Graz, Austria (S.L.-H., J.V., S. Sedej)
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.)
| | - Michael Holzer
- Otto-Loewi Research Centre, Division of Pharmacology (M.H.), Medical University of Graz, Austria
| | - Brent M Wood
- Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.)
| | - Mahmoud Abdellatif
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Ingrid Matzer
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Michael Sacherer
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Snjezana Radulovic
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Markus Wallner
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Milan Ivanov
- Institute for Medical Research, University of Belgrade, Serbia (M.I.)
| | - Stefan Wagner
- Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum Regensburg, Germany (S.W., S. Sossalla)
| | - Samuel Sossalla
- Klinik für Kardiologie und Pneumologie, Georg-August-Universität Göttingen, Germany (S. Sossalla).,Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum Regensburg, Germany (S.W., S. Sossalla)
| | - Dirk von Lewinski
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité University Medicine Berlin, Germany (B.P.)
| | - Joan Heller Brown
- Department of Pharmacology, University of California San Diego, La Jolla (J.H.B.)
| | - Simon Sedej
- Department of Cardiology (S.L.-H., N.D., J.V., M.A., I.M., M.S., S.R., M.W., D.v.L., S. Sedej), Medical University of Graz, Austria.,BioTechMed Graz, Austria (S.L.-H., J.V., S. Sedej).,Faculty of Medicine, Institute of Physiology, University of Maribor, Slovenia (S. Sedej)
| | - Julie Bossuyt
- Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.)
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA (S.L.-H., A.W.H., S.M., B.M.W., J.B., D.M.B.)
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18
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The role of A-kinase anchoring proteins in cardiac oxidative stress. Biochem Soc Trans 2020; 47:1341-1353. [PMID: 31671182 PMCID: PMC6824835 DOI: 10.1042/bst20190228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 09/08/2019] [Accepted: 09/10/2019] [Indexed: 12/18/2022]
Abstract
Cardiac stress initiates a pathological remodeling process that is associated with cardiomyocyte loss and fibrosis that ultimately leads to heart failure. In the injured heart, a pathologically elevated synthesis of reactive oxygen species (ROS) is the main driver of oxidative stress and consequent cardiomyocyte dysfunction and death. In this context, the cAMP-dependent protein kinase (PKA) plays a central role in regulating signaling pathways that protect the heart against ROS-induced cardiac damage. In cardiac cells, spatiotemporal regulation of PKA activity is controlled by A-kinase anchoring proteins (AKAPs). This family of scaffolding proteins tether PKA and other transduction enzymes at subcellular microdomains where they can co-ordinate cellular responses regulating oxidative stress. In this review, we will discuss recent literature illustrating the role of PKA and AKAPs in modulating the detrimental impact of ROS production on cardiac function.
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19
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The Role of Cyclic AMP Signaling in Cardiac Fibrosis. Cells 2019; 9:cells9010069. [PMID: 31888098 PMCID: PMC7016856 DOI: 10.3390/cells9010069] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/18/2022] Open
Abstract
Myocardial stress and injury invariably promote remodeling of the cardiac tissue, which is associated with cardiomyocyte death and development of fibrosis. The fibrotic process is initially triggered by the differentiation of resident cardiac fibroblasts into myofibroblasts. These activated fibroblasts display increased proliferative capacity and secrete large amounts of extracellular matrix. Uncontrolled myofibroblast activation can thus promote heart stiffness, cardiac dysfunction, arrhythmias, and progression to heart failure. Despite the well-established role of myofibroblasts in mediating cardiac disease, our current knowledge on how signaling pathways promoting fibrosis are regulated and coordinated in this cell type is largely incomplete. In this respect, cyclic adenosine monophosphate (cAMP) signaling acts as a major modulator of fibrotic responses activated in fibroblasts of injured or stressed hearts. In particular, accumulating evidence now suggests that upstream cAMP modulators including G protein-coupled receptors, adenylyl cyclases (ACs), and phosphodiesterases (PDEs); downstream cAMP effectors such as protein kinase A (PKA) and the guanine nucleotide exchange factor Epac; and cAMP signaling organizers such as A-kinase anchoring proteins (AKAPs) modulate a variety of fundamental cellular processes involved in myocardial fibrosis including myofibroblast differentiation, proliferation, collagen secretion, and invasiveness. The current review will discuss recent advances highlighting the role of cAMP and AKAP-mediated signaling in regulating pathophysiological responses controlling cardiac fibrosis.
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