1
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Dallagnol JCC, Volkovich M, Chatenet D, Allen BG, Hébert TE. G Protein-Biased Agonists for Intracellular Angiotensin Receptors Promote Collagen Secretion in Myofibroblasts. ACS Chem Biol 2023; 18:2050-2062. [PMID: 37611227 DOI: 10.1021/acschembio.3c00319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
Photoactivatable ligands remain valuable tools to study the spatiotemporal aspects of cellular signaling. However, the synthesis, handling, and biological validation of such compounds remain challenging, especially when dealing with peptides. We report an optimized synthetic strategy, where laborious preparation of dimethoxy-nitrobenzyl-tyrosine building blocks was replaced by direct functionalization of amino acid side chains while peptides remained coupled to resin, reducing both preparation time and cost. Our caged peptides were designed to investigate cellular responses mediated by intracellular angiotensin II receptors (iATR) upon interaction with known biased and unbiased ligands. The pathophysiological roles of iATRs remain poorly understood, and we sought to develop ligands to explore this. Initial validation showed that our caged ligands undergo rapid photolysis and produced functionally active peptides upon UV exposure. We also show, for the first time, that different biased ligands (β-arrestin- vs G protein-biased analogues) evoked distinct responses when uncaged in adult rat myofibroblasts. Intracellularly targeted versions of Ang II (unbiased) or G protein-biased analogues (TRV055, TRV056) were more effective than β-arrestin-biased Ang II analogues (SI, TRV026, and TRV27) in inducing collagen secretion, suggesting a divergent role in regulating the fibrotic response.
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Affiliation(s)
- Juliana C C Dallagnol
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Laval H7V 5B7, Québec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal H3G 1Y6, Québec, Canada
- Montreal Heart Institute, Montréal H1T 1C8, Québec, Canada
| | - Mikhail Volkovich
- Department of Pharmacology and Therapeutics, McGill University, Montréal H3G 1Y6, Québec, Canada
- Montreal Heart Institute, Montréal H1T 1C8, Québec, Canada
| | - David Chatenet
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Groupe de Recherche en Ingénierie des Peptides et en Pharmacothérapie (GRIPP), Université du Québec, Laval H7V 5B7, Québec, Canada
| | - Bruce G Allen
- Montreal Heart Institute, Montréal H1T 1C8, Québec, Canada
- Departments of Biochemistry and Molecular Medicine, Medicine, Pharmacology and Physiology, Université de Montréal, Montréal H3C 3J7, Québec, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal H3G 1Y6, Québec, Canada
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2
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Grogan A, Lucero EY, Jiang H, Rockman HA. Pathophysiology and pharmacology of G protein-coupled receptors in the heart. Cardiovasc Res 2023; 119:1117-1129. [PMID: 36534965 PMCID: PMC10202650 DOI: 10.1093/cvr/cvac171] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/30/2022] [Accepted: 10/06/2022] [Indexed: 08/10/2023] Open
Abstract
G protein-coupled receptors (GPCRs), comprising the largest superfamily of cell surface receptors, serve as fundamental modulators of cardiac health and disease owing to their key roles in the regulation of heart rate, contractile dynamics, and cardiac function. Accordingly, GPCRs are heavily pursued as drug targets for a wide variety of cardiovascular diseases ranging from heart failure, cardiomyopathy, and arrhythmia to hypertension and coronary artery disease. Recent advancements in understanding the signalling mechanisms, regulation, and pharmacological properties of GPCRs have provided valuable insights that will guide the development of novel therapeutics. Herein, we review the cellular signalling mechanisms, pathophysiological roles, and pharmacological developments of the major GPCRs in the heart, highlighting the β-adrenergic, muscarinic, and angiotensin receptors as exemplar subfamilies.
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Affiliation(s)
- Alyssa Grogan
- Department of Medicine, Duke University Medical Center, DUMC 3104, 226 CARL Building, Durham, NC 27710, USA
| | - Emilio Y Lucero
- Department of Medicine, Duke University Medical Center, DUMC 3104, 226 CARL Building, Durham, NC 27710, USA
| | - Haoran Jiang
- Department of Medicine, Duke University Medical Center, DUMC 3104, 226 CARL Building, Durham, NC 27710, USA
| | - Howard A Rockman
- Department of Medicine, Duke University Medical Center, DUMC 3104, 226 CARL Building, Durham, NC 27710, USA
- Cell Biology, Duke University Medical Center, DUMC 3104, 226 CARL Building, 12 Durham, NC 27710, USA
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3
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Kiessling M, Djalinac N, Voglhuber J, Ljubojevic-Holzer S. Nuclear Calcium in Cardiac (Patho)Physiology: Small Compartment, Big Impact. Biomedicines 2023; 11:biomedicines11030960. [PMID: 36979939 PMCID: PMC10046765 DOI: 10.3390/biomedicines11030960] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
The nucleus of a cardiomyocyte has been increasingly recognized as a morphologically distinct and partially independent calcium (Ca2+) signaling microdomain, with its own Ca2+-regulatory mechanisms and important effects on cardiac gene expression. In this review, we (1) provide a comprehensive overview of the current state of research on the dynamics and regulation of nuclear Ca2+ signaling in cardiomyocytes, (2) address the role of nuclear Ca2+ in the development and progression of cardiac pathologies, such as heart failure and atrial fibrillation, and (3) discuss novel aspects of experimental methods to investigate nuclear Ca2+ handling and its downstream effects in the heart. Finally, we highlight current challenges and limitations and recommend future directions for addressing key open questions.
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Affiliation(s)
- Mara Kiessling
- Department of Cardiology, Medical University of Graz, 8036 Graz, Austria
| | - Nataša Djalinac
- Department of Biology, University of Padua, 35122 Padova, Italy
| | - Julia Voglhuber
- Department of Cardiology, Medical University of Graz, 8036 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
| | - Senka Ljubojevic-Holzer
- Department of Cardiology, Medical University of Graz, 8036 Graz, Austria
- BioTechMed Graz, 8010 Graz, Austria
- Gottfried Schatz Research Center, Division of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
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4
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Demydenko K, Ekhteraei-Tousi S, Roderick HL. Inositol 1,4,5-trisphosphate receptors in cardiomyocyte physiology and disease. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210319. [PMID: 36189803 PMCID: PMC9527928 DOI: 10.1098/rstb.2021.0319] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The contraction of cardiac muscle underlying the pumping action of the heart is mediated by the process of excitation-contraction coupling (ECC). While triggered by Ca2+ entry across the sarcolemma during the action potential, it is the release of Ca2+ from the sarcoplasmic reticulum (SR) intracellular Ca2+ store via ryanodine receptors (RyRs) that plays the major role in induction of contraction. Ca2+ also acts as a key intracellular messenger regulating transcription underlying hypertrophic growth. Although Ca2+ release via RyRs is by far the greatest contributor to the generation of Ca2+ transients in the cardiomyocyte, Ca2+ is also released from the SR via inositol 1,4,5-trisphosphate (InsP3) receptors (InsP3Rs). This InsP3-induced Ca2+ release modifies Ca2+ transients during ECC, participates in directing Ca2+ to the mitochondria, and stimulates the transcription of genes underlying hypertrophic growth. Central to these specific actions of InsP3Rs is their localization to responsible signalling microdomains, the dyad, the SR-mitochondrial interface and the nucleus. In this review, the various roles of InsP3R in cardiac (patho)physiology and the mechanisms by which InsP3 signalling selectively influences the different cardiomyocyte cell processes in which it is involved will be presented. This article is part of the theme issue ‘The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease’.
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Affiliation(s)
- Kateryna Demydenko
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Samaneh Ekhteraei-Tousi
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - H Llewelyn Roderick
- Laboratory of Experimental Cardiology, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
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5
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Fasciani I, Carli M, Petragnano F, Colaianni F, Aloisi G, Maggio R, Scarselli M, Rossi M. GPCRs in Intracellular Compartments: New Targets for Drug Discovery. Biomolecules 2022; 12:1343. [PMID: 36291552 PMCID: PMC9599219 DOI: 10.3390/biom12101343] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 08/02/2023] Open
Abstract
The architecture of eukaryotic cells is defined by extensive membrane-delimited compartments, which entails separate metabolic processes that would otherwise interfere with each other, leading to functional differences between cells. G protein-coupled receptors (GPCRs) are the largest class of cell surface receptors, and their signal transduction is traditionally viewed as a chain of events initiated from the plasma membrane. Furthermore, their intracellular trafficking, internalization, and recycling were considered only to regulate receptor desensitization and cell surface expression. On the contrary, accumulating data strongly suggest that GPCRs also signal from intracellular compartments. GPCRs localize in the membranes of endosomes, nucleus, Golgi and endoplasmic reticulum apparatuses, mitochondria, and cell division compartments. Importantly, from these sites they have shown to orchestrate multiple signals that regulate different cell pathways. In this review, we summarize the current knowledge of this fascinating phenomenon, explaining how GPCRs reach the intracellular sites, are stimulated by the endogenous ligands, and their potential physiological/pathophysiological roles. Finally, we illustrate several mechanisms involved in the modulation of the compartmentalized GPCR signaling by drugs and endogenous ligands. Understanding how GPCR signaling compartmentalization is regulated will provide a unique opportunity to develop novel pharmaceutical approaches to target GPCRs and potentially lead the way towards new therapeutic approaches.
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Affiliation(s)
- Irene Fasciani
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Marco Carli
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Francesco Petragnano
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Francesco Colaianni
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Gabriella Aloisi
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Roberto Maggio
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
| | - Marco Scarselli
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Mario Rossi
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, 67100 L’Aquila, Italy
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6
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Kuo C, Nikan M, Yeh ST, Chappell AE, Tanowitz M, Seth PP, Prakash TP, Mullick AE. Targeted Delivery of Antisense Oligonucleotides Through Angiotensin Type 1 Receptor. Nucleic Acid Ther 2022; 32:300-311. [PMID: 35612431 DOI: 10.1089/nat.2021.0105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We evaluated the potential of AGTR1, the principal receptor for angiotensin II (Ang II) and a member of the G protein-coupled receptor family, for targeted delivery of antisense oligonucleotides (ASOs) in cells and tissues with abundant AGTR1 expression. Ang II peptide ASO conjugates maintained robust AGTR1 signaling and receptor internalization when ASO was placed at the N-terminus of the peptide, but not at C-terminus. Conjugation of Ang II peptide improved ASO potency up to 12- to 17-fold in AGTR1-expressing cells. Additionally, evaluation of Ang II conjugates in cells lacking AGTR1 revealed no enhancement of ASO potency. Ang II peptide conjugation improves potency of ASO in mouse heart, adrenal, and adipose tissues. The data presented in this report add to a growing list of approaches for improving ASO potency in extrahepatic tissues.
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Affiliation(s)
- Carol Kuo
- Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Mehran Nikan
- Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | - Steve T Yeh
- Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
| | | | | | - Punit P Seth
- Ionis Pharmaceuticals, Inc., Carlsbad, California, USA
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7
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Ca 2+ mishandling and mitochondrial dysfunction: a converging road to prediabetic and diabetic cardiomyopathy. Pflugers Arch 2022; 474:33-61. [PMID: 34978597 PMCID: PMC8721633 DOI: 10.1007/s00424-021-02650-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/17/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022]
Abstract
Diabetic cardiomyopathy is defined as the myocardial dysfunction that suffers patients with diabetes mellitus (DM) in the absence of hypertension and structural heart diseases such as valvular or coronary artery dysfunctions. Since the impact of DM on cardiac function is rather silent and slow, early stages of diabetic cardiomyopathy, known as prediabetes, are poorly recognized, and, on many occasions, cardiac illness is diagnosed only after a severe degree of dysfunction was reached. Therefore, exploration and recognition of the initial pathophysiological mechanisms that lead to cardiac dysfunction in diabetic cardiomyopathy are of vital importance for an on-time diagnosis and treatment of the malady. Among the complex and intricate mechanisms involved in diabetic cardiomyopathy, Ca2+ mishandling and mitochondrial dysfunction have been described as pivotal early processes. In the present review, we will focus on these two processes and the molecular pathway that relates these two alterations to the earlier stages and the development of diabetic cardiomyopathy.
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8
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Qi Z, Wang T, Chen X, Wong CK, Ding Q, Sauer H, Chen ZF, Long C, Yao X, Cai Z, Tsang SY. Extracellular and Intracellular Angiotensin II Regulate the Automaticity of Developing Cardiomyocytes via Different Signaling Pathways. Front Mol Biosci 2021; 8:699827. [PMID: 34513920 PMCID: PMC8425478 DOI: 10.3389/fmolb.2021.699827] [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: 04/24/2021] [Accepted: 07/27/2021] [Indexed: 12/02/2022] Open
Abstract
Angiotensin II (Ang II) plays an important role in regulating various physiological processes. However, little is known about the existence of intracellular Ang II (iAng II), whether iAng II would regulate the automaticity of early differentiating cardiomyocytes, and the underlying mechanism involved. Here, iAng II was detected by immunocytochemistry and ultra-high performance liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry in mouse embryonic stem cell–derived cardiomyocytes (mESC-CMs) and neonatal rat ventricular myocytes. Expression of AT1R-YFP in mESC-CMs revealed that Ang II type 1 receptors were located on the surface membrane, while immunostaining of Ang II type 2 receptors (AT2R) revealed that AT2R were predominately located on the nucleus and the sarcoplasmic reticulum. While extracellular Ang II increased spontaneous action potentials (APs), dual patch clamping revealed that intracellular delivery of Ang II or AT2R activator C21 decreased spontaneous APs. Interestingly, iAng II was found to decrease the caffeine-induced increase in spontaneous APs and caffeine-induced calcium release, suggesting that iAng II decreased spontaneous APs via the AT2R- and ryanodine receptor–mediated pathways. This is the first study that provides evidence of the presence and function of iAng II in regulating the automaticity behavior of ESC-CMs and may therefore shed light on the role of iAng II in fate determination.
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Affiliation(s)
- Zenghua Qi
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China.,Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China
| | - Tao Wang
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon, Hong Kong, SAR China
| | - Xiangmao Chen
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Chun Kit Wong
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China
| | - Qianqian Ding
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China
| | - Heinrich Sauer
- Department of Physiology, Justus Liebig University Giessen, Giessen, Germany
| | - Zhi-Feng Chen
- Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xiaoqiang Yao
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon, Hong Kong, SAR China
| | - Suk Ying Tsang
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China.,Key Laboratory for Regenerative Medicine, Ministry of Education, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China.,State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong, SAR China
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9
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Lino CA, de Bortoli Teixeira L, Capelupe Simões S, de Oliveira Silva T, Diniz GP, da Costa-Neto CM, Barreto-Chaves MLM. Beta-arrestin 2 mediates cardiac hypertrophy induced by thyroid hormones via AT1R. J Cell Physiol 2021; 236:4640-4654. [PMID: 33345322 DOI: 10.1002/jcp.30187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/30/2022]
Abstract
We have previously reported that angiotensin II receptor type 1 (AT1R) contributes to the hypertrophic effects of thyroid hormones (TH) in cardiac cells. Even though evidence indicates crosstalks between TH and AT1R, the underlying mechanisms are poorly understood. Beta-arrestin (ARRB) signaling has been described as noncanonical signal transduction pathway that exerts important effects in the cardiovascular system through G-protein-coupled receptors, as AT1R. Herein, we investigated the contribution of ARRB signaling in TH-induced cardiomyocyte hypertrophy. Primary cardiomyocyte cultures were treated with Triiodothyronine (T3) to induce cell hypertrophy. T3 rapidly activates extracellular signal-regulated kinase 1/2 (ERK1/2) signaling, which was partially inhibited by AT1R blockade. Also, ERK1/2 inhibition attenuated the hypertrophic effects of T3. ARRB2 was upregulated by T3, and small interfering RNA assays revealed the role of ARRB2-but not ARRB1-on ERK1/2 activation and cardiomyocyte hypertrophy. Corroborating these findings, the ARRB2-overexpressed cells showed increased expression of hypertrophic markers, which were attenuated by ERK1/2 inhibition. Immunocytochemistry and immunoprecipitation assays revealed the increased expression of nuclear AT1R after T3 stimulation and the increased interaction of AT1R/ARRB2. The inhibition of endocytosis also attenuated the T3 effects on cardiac cells. Our results evidence the contribution of ARRB2 on ERK1/2 activation and cardiomyocyte hypertrophy induced by T3 via AT1R.
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Affiliation(s)
- Caroline Antunes Lino
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Larissa de Bortoli Teixeira
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | - Sarah Capelupe Simões
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Gabriela Placoná Diniz
- Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Claudio Miguel da Costa-Neto
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo, Brazil
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10
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Qi XY, Vahdati Hassani F, Hoffmann D, Xiao J, Xiong F, Villeneuve LR, Ljubojevic-Holzer S, Kamler M, Abu-Taha I, Heijman J, Bers DM, Dobrev D, Nattel S. Inositol Trisphosphate Receptors and Nuclear Calcium in Atrial Fibrillation. Circ Res 2020; 128:619-635. [PMID: 33375812 DOI: 10.1161/circresaha.120.317768] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
RATIONALE The mechanisms underlying atrial fibrillation (AF), the most common clinical arrhythmia, are poorly understood. Nucleoplasmic Ca2+ regulates gene expression, but the nature and significance of nuclear Ca2+-changes in AF are largely unknown. OBJECTIVE To elucidate mechanisms by which AF alters atrial-cardiomyocyte nuclear Ca2+ ([Ca2+]Nuc) and CaMKII (Ca2+/calmodulin-dependent protein kinase-II)-related signaling. METHODS AND RESULTS Atrial cardiomyocytes were isolated from control and AF dogs (kept in AF by atrial tachypacing [600 bpm × 1 week]). [Ca2+]Nuc and cytosolic [Ca2+] ([Ca2+]Cyto) were recorded via confocal microscopy. Diastolic [Ca2+]Nuc was greater than [Ca2+]Cyto under control conditions, while resting [Ca2+]Nuc was similar to [Ca2+]Cyto; both diastolic and resting [Ca2+]Nuc increased with AF. IP3R (Inositol-trisphosphate receptor) stimulation produced larger [Ca2+]Nuc increases in AF versus control cardiomyocytes, and IP3R-blockade suppressed the AF-related [Ca2+]Nuc differences. AF upregulated nuclear protein expression of IP3R1 (IP3R-type 1) and of phosphorylated CaMKII (immunohistochemistry and immunoblot) while decreasing the nuclear/cytosolic expression ratio for HDAC4 (histone deacetylase type-4). Isolated atrial cardiomyocytes tachypaced at 3 Hz for 24 hours mimicked AF-type [Ca2+]Nuc changes and L-type calcium current decreases versus 1-Hz-paced cardiomyocytes; these changes were prevented by IP3R knockdown with short-interfering RNA directed against IP3R1. Nuclear/cytosolic HDAC4 expression ratio was decreased by 3-Hz pacing, while nuclear CaMKII phosphorylation was increased. Either CaMKII-inhibition (by autocamtide-2-related peptide) or IP3R-knockdown prevented the CaMKII-hyperphosphorylation and nuclear-to-cytosolic HDAC4 shift caused by 3-Hz pacing. In human atrial cardiomyocytes from AF patients, nuclear IP3R1-expression was significantly increased, with decreased nuclear/nonnuclear HDAC4 ratio. MicroRNA-26a was predicted to target ITPR1 (confirmed by luciferase assay) and was downregulated in AF atrial cardiomyocytes; microRNA-26a silencing reproduced AF-induced IP3R1 upregulation and nuclear diastolic Ca2+-loading. CONCLUSIONS AF increases atrial-cardiomyocyte nucleoplasmic [Ca2+] by IP3R1-upregulation involving miR-26a, leading to enhanced IP3R1-CaMKII-HDAC4 signaling and L-type calcium current downregulation. Graphic Abstract: A graphic abstract is available for this article.
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Affiliation(s)
- Xiao-Yan Qi
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Faezeh Vahdati Hassani
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Dennis Hoffmann
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Jiening Xiao
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Feng Xiong
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | - Louis R Villeneuve
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.)
| | | | - Markus Kamler
- Departments of Thoracic and Cardiovascular Surgery Huttrop (M.K.)
| | - Issam Abu-Taha
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Jordi Heijman
- Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.).,Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, the Netherlands (J.H.)
| | - Donald M Bers
- Physiology, University of California, Davis (S.L.-H., D.M.B.)
| | - Dobromir Dobrev
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.).,Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.)
| | - Stanley Nattel
- Medicine, Montreal Heart Institute, Université de Montréal, Canada (X.-Y.Q., F.V.H., J.X., F.X., L.R.V., D.D., S.N.).,Institute of Pharmacology, West German Heart and Vascular Center, Medical Faculty, University Duisburg-Essen, Germany (D.H., I.A.-T., J.H., D.D., S.N.).,Pharmacology, McGill University Montreal, Canada (S.N.).,IHU LIRYC, Bordeaux, France (S.N.)
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11
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Angiotensin dependent and angiotensin independent protective effects of renin-b in H9c2 cells after anoxia. Sci Rep 2020; 10:19689. [PMID: 33184370 PMCID: PMC7661495 DOI: 10.1038/s41598-020-76712-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/20/2020] [Indexed: 12/20/2022] Open
Abstract
The renin-angiotensin system is known to regulate blood pressure as well as water- and electrolyte balance. An activated RAS is involved in the development of hypertension and hypertension-related organ damage. Thus, inhibitors of the RAS are protective and markedly increasing the life span of patients. In contrast, renin transcripts have been discovered encoding a cytoplasmatic renin isoform, termed renin-b, which is not harmful but may be even protective. Here we demonstrate that depletion of renin-b encoding transcripts by small interference RNA decreased ATP levels and increased basal necrosis as well as apoptosis rates. Furthermore, renin-b depletion potentiated the anoxia-induced increase of necrosis rates. Vice versa, overexpression of renin-b prevented the anoxia-induced increase of caspase-mediated apoptosis rates. Besides, cells overexpressing renin-b exhibited even reduced mitochondrial mediated apoptosis rates under anoxia, when compared with normoxic conditions, as indicated by Annexin V labeling. However, whereas the protective effect of renin-b on caspase-mediated apoptosis was completely blocked by the renin inhibitor CH732, the effect on mitochondrial-mediated apoptosis was not affected by CH732 at all. From these data we conclude that renin-b overexpression mediates cardioprotective effects under anoxia with respect to mitochondrial induced apoptosis angiotensin-independently, but with respect to caspase induced apoptosis likely in an angiotensin-dependent manner.
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12
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Labandeira-Garcia JL, Valenzuela R, Costa-Besada MA, Villar-Cheda B, Rodriguez-Perez AI. The intracellular renin-angiotensin system: Friend or foe. Some light from the dopaminergic neurons. Prog Neurobiol 2020; 199:101919. [PMID: 33039415 PMCID: PMC7543790 DOI: 10.1016/j.pneurobio.2020.101919] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 08/20/2020] [Accepted: 10/04/2020] [Indexed: 12/11/2022]
Abstract
The renin-angiotensin system (RAS) is one of the oldest hormone systems in vertebrate phylogeny. RAS was initially related to regulation of blood pressure and sodium and water homeostasis. However, local or paracrine RAS were later identified in many tissues, including brain, and play a major role in their physiology and pathophysiology. In addition, a major component, ACE2, is the entry receptor for SARS-CoV-2. Overactivation of tissue RAS leads several oxidative stress and inflammatory processes involved in aging-related degenerative changes. In addition, a third level of RAS, the intracellular or intracrine RAS (iRAS), with still unclear functions, has been observed. The possible interaction between the intracellular and extracellular RAS, and particularly the possible deleterious or beneficial effects of the iRAS activation are controversial. The dopaminergic system is particularly interesting to investigate the RAS as important functional interactions between dopamine and RAS have been observed in the brain and several peripheral tissues. Our recent observations in mitochondria and nucleus of dopaminergic neurons may clarify the role of the iRAS. This may be important for the developing of new therapeutic strategies, since the effects on both extracellular and intracellular RAS must be taken into account, and perhaps better understanding of COVID-19 cell mechanisms.
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Affiliation(s)
- Jose L Labandeira-Garcia
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain.
| | - Rita Valenzuela
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Maria A Costa-Besada
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Begoña Villar-Cheda
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
| | - Ana I Rodriguez-Perez
- Laboratory of Cellular and Molecular Neurobiology of Parkinson's Disease, Research Center for Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute (IDIS), University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CiberNed), Madrid, Spain
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13
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Rukavina Mikusic NL, Silva MG, Pineda AM, Gironacci MM. Angiotensin Receptors Heterodimerization and Trafficking: How Much Do They Influence Their Biological Function? Front Pharmacol 2020; 11:1179. [PMID: 32848782 PMCID: PMC7417933 DOI: 10.3389/fphar.2020.01179] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/20/2020] [Indexed: 01/03/2023] Open
Abstract
G-protein–coupled receptors (GPCRs) are targets for around one third of currently approved and clinical prescribed drugs and represent the largest and most structurally diverse family of transmembrane signaling proteins, with almost 1000 members identified in the human genome. Upon agonist stimulation, GPCRs are internalized and trafficked inside the cell: they may be targeted to different organelles, recycled back to the plasma membrane or be degraded. Once inside the cell, the receptors may initiate other signaling pathways leading to different biological responses. GPCRs’ biological function may also be influenced by interaction with other receptors. Thus, the ultimate cellular response may depend not only on the activation of the receptor from the cell membrane, but also from receptor trafficking and/or the interaction with other receptors. This review is focused on angiotensin receptors and how their biological function is influenced by trafficking and interaction with others receptors.
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Affiliation(s)
- Natalia L Rukavina Mikusic
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Dpto. Química Biológica, IQUIFIB (UBA-CONICET), Buenos Aires, Argentina
| | - Mauro G Silva
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Dpto. Química Biológica, IQUIFIB (UBA-CONICET), Buenos Aires, Argentina
| | - Angélica M Pineda
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Dpto. Química Biológica, IQUIFIB (UBA-CONICET), Buenos Aires, Argentina
| | - Mariela M Gironacci
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Dpto. Química Biológica, IQUIFIB (UBA-CONICET), Buenos Aires, Argentina
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14
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Stoll D, Yokota R, Sanches Aragão D, Casarini DE. Both aldosterone and spironolactone can modulate the intracellular ACE/ANG II/AT1 and ACE2/ANG (1-7)/MAS receptor axes in human mesangial cells. Physiol Rep 2020; 7:e14105. [PMID: 31165585 PMCID: PMC6548847 DOI: 10.14814/phy2.14105] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 04/10/2019] [Accepted: 04/24/2019] [Indexed: 12/01/2022] Open
Abstract
The kidney is an important target of the renin‐ANG‐aldosterone system (RAAS). To date, several studies have demonstrated the existence of a local RAAS in various tissues, including the renal tissue. The mineralocorticoid aldosterone is known to play a critical role in the classical RAAS; however, its effect on mesangial cells (MCs) remains to be elucidated. Based on this, our aim was to investigate whether aldosterone stimulation can modulate the intracellular RAAS of immortalized human MCs by evaluating ANG‐converting enzyme (ACE)/ANG II/ANG II receptor type 1 (AT1) and ANG‐converting enzyme 2 (ACE2)/ANG (1‐7)/MAS receptor axes. To realise this, protein expression, enzyme activity, and immunofluorescence were performed under aldosterone stimulation and in the presence of the mineralocorticoid receptor (MR) antagonist spironolactone (SPI). We observed that high doses of aldosterone increase ACE activity. The effect of aldosterone on the catalytic activity of ACE was completely abolished with the pretreatment of SPI suggesting that the aldosterone‐induced cell injuries through ANG II release were attenuated. Aldosterone treatment also decreased the expression of MAS receptor, but did not alter the expression or the catalytic activity of ACE 2 and ANG (1‐7) levels. Spironolactone modulated the localization of ANG II and AT1 receptor and decreased ANG (1‐7) and MAS receptor levels. Our data suggest that both aldosterone and the MR receptor antagonist can modulate both of these axes and that spironolactone can protect MCs from the damage induced by aldosterone.
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Affiliation(s)
- Danielle Stoll
- Escola Paulista de Medicina - Department of Medicine, Nephrology Division, Universidade Federal de São Paulo, UNIFESP, São Paulo, Brazil
| | - Rodrigo Yokota
- Escola Paulista de Medicina - Department of Medicine, Nephrology Division, Universidade Federal de São Paulo, UNIFESP, São Paulo, Brazil
| | - Danielle Sanches Aragão
- Escola Paulista de Medicina - Department of Medicine, Nephrology Division, Universidade Federal de São Paulo, UNIFESP, São Paulo, Brazil
| | - Dulce E Casarini
- Escola Paulista de Medicina - Department of Medicine, Nephrology Division, Universidade Federal de São Paulo, UNIFESP, São Paulo, Brazil
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15
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Escobales N, Nuñez RE, Javadov S. Mitochondrial angiotensin receptors and cardioprotective pathways. Am J Physiol Heart Circ Physiol 2019; 316:H1426-H1438. [PMID: 30978131 PMCID: PMC6620675 DOI: 10.1152/ajpheart.00772.2018] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/15/2019] [Accepted: 04/01/2019] [Indexed: 12/13/2022]
Abstract
A growing body of data provides strong evidence that intracellular angiotensin II (ANG II) plays an important role in mammalian cell function and is involved in the pathogenesis of human diseases such as hypertension, diabetes, inflammation, fibrosis, arrhythmias, and kidney disease, among others. Recent studies also suggest that intracellular ANG II exerts protective effects in cells during high extracellular levels of the hormone or during chronic stimulation of the local tissue renin-angiotensin system (RAS). Notably, the intracellular RAS (iRAS) described in neurons, fibroblasts, renal cells, and cardiomyocytes provided new insights into regulatory mechanisms mediated by intracellular ANG II type 1 (AT1Rs) and 2 (AT2Rs) receptors, particularly, in mitochondria and nucleus. For instance, ANG II through nuclear AT1Rs promotes protective mechanisms by stimulating the AT2R signaling cascade, which involves mitochondrial AT2Rs and Mas receptors. The stimulation of nuclear ANG II receptors enhances mitochondrial biogenesis through peroxisome proliferator-activated receptor-γ coactivator-1α and increases sirtuins activity, thus protecting the cell against oxidative stress. Recent studies in ANG II-induced preconditioning suggest that plasma membrane AT2R stimulation exerts protective effects against cardiac ischemia-reperfusion by modulating mitochondrial AT1R and AT2R signaling. These studies indicate that iRAS promotes the protection of cells through nuclear AT1R signaling, which, in turn, promotes AT2R-dependent processes in mitochondria. Thus, despite abundant data on the deleterious effects of intracellular ANG II, a growing body of studies also supports a protective role for iRAS that could be of relevance to developing new therapeutic strategies. This review summarizes and discusses previous studies on the role of iRAS, particularly emphasizing the protective and counterbalancing actions of iRAS, mitochondrial ANG II receptors, and their implications for organ protection.
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Affiliation(s)
- Nelson Escobales
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
| | - Rebeca E Nuñez
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
| | - Sabzali Javadov
- Department of Physiology, University of Puerto Rico School of Medicine , San Juan, Puerto Rico
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16
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Nucleoligands-repurposing G Protein-coupled Receptor Ligands to Modulate Nuclear-localized G Protein-coupled Receptors in the Cardiovascular System. J Cardiovasc Pharmacol 2019; 71:193-204. [PMID: 28858907 DOI: 10.1097/fjc.0000000000000535] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There is significant evidence that internal pools of G protein-coupled receptors (GPCRs) exist and may be affected by both endogenous signaling molecules and hydrophobic pharmaceutical ligands, once assumed to only affect cell surface versions of these receptors. Here, we discuss evidence that the biology of nuclear GPCRs in particular is complex, rich, and highly interactive with GPCR signaling from the cell surface. Caging existing GPCR ligands may be an excellent means of further stratifying the phenotypic effects of known pharmacophores such as β-adrenergic, angiotensin II, and type B endothelin receptor ligands in the cardiovascular system. We describe some synthetic strategies we have used to design ligands to go from in cellulo to in vivo experiments. We also consider how surface and intracellular GPCR signaling might be integrated and ways to dissect this. If they could be selectively targeted, nuclear GPCRs and their associated nucleoligands would represent a completely novel area for exploration by Pharma.
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17
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Mhatre KN, Wakula P, Klein O, Bisping E, Völkl J, Pieske B, Heinzel FR. Crosstalk between FGF23- and angiotensin II-mediated Ca 2+ signaling in pathological cardiac hypertrophy. Cell Mol Life Sci 2018; 75:4403-4416. [PMID: 30062428 PMCID: PMC11105615 DOI: 10.1007/s00018-018-2885-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 07/16/2018] [Accepted: 07/19/2018] [Indexed: 02/07/2023]
Abstract
Heart failure (HF) manifestation and progression are driven by systemic activation of neuroendocrine signaling cascades, such as the renin-angiotensin aldosterone system (RAAS). Fibroblast growth factor 23 (FGF23), an endocrine hormone, is linked to HF and cardiovascular mortality. It is also a mediator of left-ventricular hypertrophy (LVH). In vivo, high circulating levels of FGF23 are associated with an altered systemic RAAS response. FGF23 is proposed to trigger pathological signaling mediated by Ca2+-regulated transcriptional pathways. In the present study, we investigated Ca2+-dependent signaling of FGF23 in ventricular cardiomyocytes and its association with angiotensin II (ATII). In neonatal rat ventricular myocytes (NRVMs), both ATII and FGF23 induced hypertrophy as observed by an increase in cell area and hypertrophic gene expression. Furthermore, FGF23 activates nuclear Ca2+-regulated CaMKII-HDAC4 pathway, similar to ATII. In addition to a global increase in cytoplasmic Ca2+, FGF23, like ATII, induced inositol 1, 4, 5-triphosphate (IP3)-induced Ca2+ release from the nucleoplasmic Ca2+ store, associated with cellular hypertrophy. Interestingly, ATII receptor antagonist, losartan, significantly attenuated FGF23-induced changes in Ca2+ homeostasis and cellular hypertrophy suggesting an involvement of ATII receptor-mediated signaling. In addition, application of FGF23 increased intracellular expression of ATII peptide and its secretion in NRVMs, confirming the participation of ATII. In conclusion, FGF23 and ATII share a common mechanism of IP3-nuclear Ca2+-dependent cardiomyocyte hypertrophy. FGF23-mediated cellular hypertrophy is associated with increased production and secretion of ATII by cardiomyocytes. These findings indicate a pathophysiological role of the cellular angiotensin system in FGF23-induced hypertrophy in ventricular cardiomyocytes.
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Affiliation(s)
- Ketaki N Mhatre
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
- Department of Cardiology, Medical University Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Paulina Wakula
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Oliver Klein
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Egbert Bisping
- Department of Cardiology, Medical University Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Jakob Völkl
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
| | - Burkert Pieske
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Berlin, Germany
- Department of Internal Medicine and Cardiology, German Heart Center, 13353, Berlin, Germany
| | - Frank R Heinzel
- Department of Internal Medicine and Cardiology, Charité University Medicine, Campus Virchow-Klinikum, 13353, Berlin, Germany.
- German Center for Cardiovascular Research (DZHK), Berlin, Germany.
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18
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Matsushima-Otsuka S, Fujiwara-Tani R, Sasaki T, Ohmori H, Nakashima C, Kishi S, Nishiguchi Y, Fujii K, Luo Y, Kuniyasu H. Significance of intranuclear angiotensin-II type 2 receptor in oral squamous cell carcinoma. Oncotarget 2018; 9:36561-36574. [PMID: 30564297 PMCID: PMC6290968 DOI: 10.18632/oncotarget.26337] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/01/2018] [Indexed: 11/29/2022] Open
Abstract
The renin-angiotensin system (RAS) is implicated in the maintenance of blood pressure and in many other biological processes including tumorigenesis and metastasis formation. Angiotensin-II (A-II) type 2 receptor (AGTR2) seems to be involved in different types of cancer; its role, however, is still unclear. Here, we investigated the role of RAS, and specifically that of AGTR2, in oral squamous cell carcinoma (OSCC) progression. AGTR2 has opposite effect on vasodilation and blood pressure compared to AGTR1. In 23 OSCCs, we found that the AGTR1/AGTR2 mRNA ratio was inversely associated with disease progression, while nuclear AGTR2 positivity was associated with disease progression. In the human OSCC cell lines HSC3 and HSC4, AGTR1 was associated with proliferation and invasion, while AGTR2 was associated with anti-apoptosis and anti-oxidative stress. Levels of nuclear AGTR2 confirmed by subcellular fractionation increased in hypoxic and hyperglycemic conditions, in which apoptosis and oxidative stress were suppressed and the redox status altered to reduction. Accumulation of nuclear AGTR2 by inhibition of extranuclear transportation decreased apoptosis and increased proliferation and invasion in HSC3 cells. Intratumoral angiotensin-II (but not serum angiotensin-II) levels were associated with stage and nuclear AGTR2 positivity. In OSCC cell lines, intracellular angiotensin-II was produced by themselves. Notably, losartan, an angiotensin receptor blocker, inhibited intracellular angiotensin-II production and AGTR2 nuclear localization to enhance the antitumoral effect of 5-FU in an OSCC tumor model. While the precise role of nuclear AGTR2 requires further examination, these data suggest that the intracellular angiotensin system might be a significant target for OSCC.
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Affiliation(s)
| | - Rina Fujiwara-Tani
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Takamitsu Sasaki
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Hitoshi Ohmori
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Chie Nakashima
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Shingo Kishi
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Yukiko Nishiguchi
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Kiyomu Fujii
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
| | - Yi Luo
- Jiangsu Province Key Laboratory of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, China
| | - Hiroki Kuniyasu
- Department of Molecular Pathology, Nara Medical University, Kashihara, Nara 634-8521, Japan
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19
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Intratubular and intracellular renin-angiotensin system in the kidney: a unifying perspective in blood pressure control. Clin Sci (Lond) 2018; 132:1383-1401. [PMID: 29986878 DOI: 10.1042/cs20180121] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/05/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022]
Abstract
The renin-angiotensin system (RAS) is widely recognized as one of the most important vasoactive hormonal systems in the physiological regulation of blood pressure and the development of hypertension. This recognition is derived from, and supported by, extensive molecular, cellular, genetic, and pharmacological studies on the circulating (tissue-to-tissue), paracrine (cell-to-cell), and intracrine (intracellular, mitochondrial, nuclear) RAS during last several decades. Now, it is widely accepted that circulating and local RAS may act independently or interactively, to regulate sympathetic activity, systemic and renal hemodynamics, body salt and fluid balance, and blood pressure homeostasis. However, there remains continuous debate with respect to the specific sources of intratubular and intracellular RAS in the kidney and other tissues, the relative contributions of the circulating RAS to intratubular and intracellular RAS, and the roles of intratubular compared with intracellular RAS to the normal control of blood pressure or the development of angiotensin II (ANG II)-dependent hypertension. Based on a lecture given at the recent XI International Symposium on Vasoactive Peptides held in Horizonte, Brazil, this article reviews recent studies using mouse models with global, kidney- or proximal tubule-specific overexpression (knockin) or deletion (knockout) of components of the RAS or its receptors. Although much knowledge has been gained from cell- and tissue-specific transgenic or knockout models, a unifying and integrative approach is now required to better understand how the circulating and local intratubular/intracellular RAS act independently, or with other vasoactive systems, to regulate blood pressure, cardiovascular and kidney function.
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20
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Dahl EF, Wu SC, Healy CL, Harsch BA, Shearer GC, O'Connell TD. Subcellular compartmentalization of proximal Gα q-receptor signaling produces unique hypertrophic phenotypes in adult cardiac myocytes. J Biol Chem 2018; 293:8734-8749. [PMID: 29610273 DOI: 10.1074/jbc.ra118.002283] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/13/2018] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors that signal through Gαq (Gq receptors), such as α1-adrenergic receptors (α1-ARs) or angiotensin receptors, share a common proximal signaling pathway that activates phospholipase Cβ1 (PLCβ1), which cleaves phosphatidylinositol 4,5-bisphosphate (PIP2) to produce inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. Despite these common proximal signaling mechanisms, Gq receptors produce distinct physiological responses, yet the mechanistic basis for this remains unclear. In the heart, Gq receptors are thought to induce myocyte hypertrophy through a mechanism termed excitation-transcription coupling, which provides a mechanistic basis for compartmentalization of calcium required for contraction versus IP3-dependent intranuclear calcium required for hypertrophy. Here, we identified subcellular compartmentalization of Gq-receptor signaling as a mechanistic basis for unique Gq receptor-induced hypertrophic phenotypes in cardiac myocytes. We show that α1-ARs co-localize with PLCβ1 and PIP2 at the nuclear membrane. Further, nuclear α1-ARs induced intranuclear PLCβ1 activity, leading to histone deacetylase 5 (HDAC5) export and a robust transcriptional response (i.e. significant up- or down-regulation of 806 genes). Conversely, we found that angiotensin receptors localize to the sarcolemma and induce sarcolemmal PLCβ1 activity, but fail to promote HDAC5 nuclear export, while producing a transcriptional response that is mostly a subset of α1-AR-induced transcription. In summary, these results link Gq-receptor compartmentalization in cardiac myocytes to unique hypertrophic transcription. They suggest a new model of excitation-transcription coupling in adult cardiac myocytes that accounts for differential Gq-receptor localization and better explains distinct physiological functions of Gq receptors.
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Affiliation(s)
| | - Steven C Wu
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455 and
| | - Chastity L Healy
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455 and
| | - Brian A Harsch
- the Department of Nutritional Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Gregory C Shearer
- the Department of Nutritional Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Timothy D O'Connell
- Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455 and
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21
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Intracrine action of angiotensin II in mesangial cells: subcellular distribution of angiotensin II receptor subtypes AT 1 and AT 2. Mol Cell Biochem 2018; 448:265-274. [PMID: 29455433 DOI: 10.1007/s11010-018-3331-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/07/2018] [Indexed: 10/18/2022]
Abstract
Biological effects of angiotensin II (AngII) such as regulation of AngII target genes may be triggered by interaction of AngII with intracellular AngII receptor types 1 and 2 (AT1 and AT2), defined as intracrine response. The aim of this study was to examine the presence of AT1 and AT2 receptors in nuclear membrane of human mesangial cells (HMCs) and evaluate the possible biological effects mediated by intracellular AT1 through an intracrine mechanism. Subcellular distribution of AT1 and AT2 was evaluated by immunofluorescence and by western blot in isolated nuclear extract. Endogenous intracellular synthesis of AngII was stimulated by high glucose (HG). Effects of HG were analyzed in the presence of candesartan, which prevents AngII internalization. Both receptors were found in nuclear membrane. Fluorescein isothiocyanate (FITC)-labeled AngII added to isolated nuclei produced a fluorescence that was reduced in the presence of losartan or PD-123319 and quenched in the presence of both inhibitors simultaneously. HG induced overexpression of fibronectin and increased cell proliferation in the presence of candesartan, indicating an intracrine action of AngII induced by HG. Results showed the presence of nuclear receptors in HMCs that can be activated by AngII through an intracrine response independent of cytoplasmic membrane AngII receptors.
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22
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Dubuc C, Savard M, Bovenzi V, Lessard A, Fortier A, Côté J, Neugebauer W, Rizzolio F, Geha S, Giordano A, Chemtob S, Gobeil F. Targeting intracellular B2 receptors using novel cell-penetrating antagonists to arrest growth and induce apoptosis in human triple-negative breast cancer. Oncotarget 2018. [PMID: 29515778 PMCID: PMC5839409 DOI: 10.18632/oncotarget.24009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are integral cell-surface proteins having a central role in tumor growth and metastasis. However, several GPCRs retain an atypical intracellular/nuclear location in various types of cancer. The pathological significance of this is currently unknown. Here we extend this observation by showing that the bradykinin B2R (BK-B2R) is nuclearly expressed in the human triple-negative breast cancer (TNBC) cell line MDA-MB-231 and in human clinical specimens of TNBC. We posited that these “nuclearized” receptors could be involved in oncogenic signaling linked to aberrant growth and survival maintenance of TNBC. We used cell-penetrating BK-B2R antagonists, including FR173657 and novel transducible, cell-permeable forms of the peptide B2R antagonist HOE 140 (NG68, NG134) to demonstrate their superior efficacy over impermeable ones (HOE 140), in blocking proliferation and promoting apoptosis of MDA-MB-231 cells. Some showed an even greater antineoplastic activity over conventional chemotherapeutic drugs in vitro. The cell-permeable B2R antagonists had less to no anticancer effects on B2R shRNA-knockdown or non-B2R expressing (COS-1) cells, indicating specificity in their action. Possible mechanisms of their anticancer effects may involve activation of p38kinase/p27Kip1 pathways. Together, our data support the existence of a possible intracrine signaling pathway via internal/nuclear B2R, critical for the growth of TNBC cells, and identify new chemical entities that enable to target the corresponding intracellular GPCRs.
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Affiliation(s)
- Céléna Dubuc
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Martin Savard
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Veronica Bovenzi
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Andrée Lessard
- Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Audrey Fortier
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Jérôme Côté
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Witold Neugebauer
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Flavio Rizzolio
- Department of Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, Philadelphia, PA, USA.,Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre-Venezia, Italy
| | - Sameh Geha
- Department of Pathology, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Québec, Canada
| | - Antonio Giordano
- Department of Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, Philadelphia, PA, USA
| | - Sylvain Chemtob
- Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine Research Center, Montréal, Québec, Canada
| | - Fernand Gobeil
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institute of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, Canada
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23
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AT1 receptor blockage impairs NF-κB activation mediated by thyroid hormone in cardiomyocytes. Pflugers Arch 2017; 470:549-558. [DOI: 10.1007/s00424-017-2088-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/06/2017] [Accepted: 11/15/2017] [Indexed: 10/18/2022]
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24
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Dewenter M, von der Lieth A, Katus HA, Backs J. Calcium Signaling and Transcriptional Regulation in Cardiomyocytes. Circ Res 2017; 121:1000-1020. [DOI: 10.1161/circresaha.117.310355] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Calcium (Ca
2+
) is a universal regulator of various cellular functions. In cardiomyocytes, Ca
2+
is the central element of excitation–contraction coupling, but also impacts diverse signaling cascades and influences the regulation of gene expression, referred to as excitation–transcription coupling. Disturbances in cellular Ca
2+
-handling and alterations in Ca
2+
-dependent gene expression patterns are pivotal characteristics of failing cardiomyocytes, with several excitation–transcription coupling pathways shown to be critically involved in structural and functional remodeling processes. Thus, targeting Ca
2+
-dependent transcriptional pathways might offer broad therapeutic potential. In this article, we (1) review cytosolic and nuclear Ca
2+
dynamics in cardiomyocytes with respect to their impact on Ca
2+
-dependent signaling, (2) give an overview on Ca
2+
-dependent transcriptional pathways in cardiomyocytes, and (3) discuss implications of excitation–transcription coupling in the diseased heart.
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Affiliation(s)
- Matthias Dewenter
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Albert von der Lieth
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Hugo A. Katus
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
| | - Johannes Backs
- From the Department of Molecular Cardiology and Epigenetics (M.D., A.v.d.L., J.B.) and Department of Cardiology (H.A.K.), Heidelberg University, Germany; and DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Germany (M.D., A.v.d.L., H.A.K., J.B.)
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25
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The intracellular angiotensin system buffers deleterious effects of the extracellular paracrine system. Cell Death Dis 2017; 8:e3044. [PMID: 28880266 PMCID: PMC5636983 DOI: 10.1038/cddis.2017.439] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/25/2017] [Accepted: 07/31/2017] [Indexed: 12/30/2022]
Abstract
The 'classical' renin-angiotensin system (RAS) is a circulating system that controls blood pressure. Local/paracrine RAS, identified in a variety of tissues, including the brain, is involved in different functions and diseases, and RAS blockers are commonly used in clinical practice. A third type of RAS (intracellular/intracrine RAS) has been observed in some types of cells, including neurons. However, its role is still unknown. The present results indicate that in brain cells the intracellular RAS counteracts the intracellular superoxide/H2O2 and oxidative stress induced by the extracellular/paracrine angiotensin II acting on plasma membrane receptors. Activation of nuclear receptors by intracellular or internalized angiotensin triggers a number of mechanisms that protect the cell, such as an increase in the levels of protective angiotensin type 2 receptors, intracellular angiotensin, PGC-1α and IGF-1/SIRT1. Interestingly, this protective mechanism is altered in isolated nuclei from brains of aged animals. The present results indicate that at least in the brain, AT1 receptor blockers acting only on the extracellular or paracrine RAS may offer better protection of cells.
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26
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Li XC, Zhuo JL. Recent Updates on the Proximal Tubule Renin-Angiotensin System in Angiotensin II-Dependent Hypertension. Curr Hypertens Rep 2017; 18:63. [PMID: 27372447 DOI: 10.1007/s11906-016-0668-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
It is well recognized that the renin-angiotensin system (RAS) exists not only as circulating, paracrine (cell to cell), but also intracrine (intracellular) system. In the kidney, however, it is difficult to dissect the respective contributions of circulating RAS versus intrarenal RAS to the physiological regulation of proximal tubular Na(+) reabsorption and hypertension. Here, we review recent studies to provide an update in this research field with a focus on the proximal tubular RAS in angiotensin II (ANG II)-induced hypertension. Careful analysis of available evidence supports the hypothesis that both local synthesis or formation and AT1 (AT1a) receptor- and/or megalin-mediated uptake of angiotensinogen (AGT), ANG I and ANG II contribute to high levels of ANG II in the proximal tubules of the kidney. Under physiological conditions, nearly all major components of the RAS including AGT, prorenin, renin, ANG I, and ANG II would be filtered by the glomerulus and taken up by the proximal tubules. In ANG II-dependent hypertension, the expression of AGT, prorenin, and (pro)renin receptors, and angiotensin-converting enzyme (ACE) is upregulated rather than downregulated in the kidney. Furthermore, hypertension damages the glomerular filtration barrier, which augments the filtration of circulating AGT, prorenin, renin, ANG I, and ANG II and their uptake in the proximal tubules. Together, increased local ANG II formation and augmented uptake of circulating ANG II in the proximal tubules, via activation of AT1 (AT1a) receptors and Na(+)/H(+) exchanger 3, may provide a powerful feedforward mechanism for promoting Na(+) retention and the development of ANG II-induced hypertension.
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Affiliation(s)
- Xiao C Li
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, 2500 North State Street, Jackson, MS, 39216-4505, USA
| | - Jia L Zhuo
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, 2500 North State Street, Jackson, MS, 39216-4505, USA.
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27
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Bundalo M, Djordjevic A, Bursac B, Zivkovic M, Koricanac G, Stanković A. Fructose-rich diet differently affects angiotensin II receptor content in the nucleus and a plasma membrane fraction of visceral adipose tissue. Appl Physiol Nutr Metab 2017; 42:1254-1263. [PMID: 28772089 DOI: 10.1139/apnm-2016-0725] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The adipose tissue renin-angiotensin system (RAS) is proposed to be a pathophysiological link between adipose tissue dysregulation and metabolic disorders induced by a fructose-rich diet (FRD). RAS can act intracellularly. We hypothesized that adipocyte nuclear membranes possess angiotensin receptor types 1 and 2 (AT1R and AT2R), which couple to nuclear signaling pathways and regulate oxidative gene expression under FRD conditions. We analyzed the effect of consumption of 10% fructose solution for 9 weeks on biochemical parameters, adipocyte morphology, and expression of AT1R, AT2R, AT1R-associated protein (ATRAP), NADPH oxidase 4 (NOX4), matrix metalloproteinase-9 (MMP-9), and manganese superoxide dismutase (MnSOD) in adipose tissue of Wistar rats. We detected AT1R and AT2R in the nuclear fraction. FRD reduced the level of angiotensin receptors in the nucleus, while increased AT1R and decreased AT2R levels were observed in the plasma membrane. FRD increased the ATRAP mRNA level and decreased MnSOD mRNA and protein levels. No significant differences were observed for MMP-9 and NOX4 mRNA levels. These findings coincided with hyperleptinemia, elevated blood pressure and triglycerides, and unchanged visceral adipose tissue mass and morphology in FRD rats. Besides providing evidence for nuclear localization of angiotensin receptors in visceral adipose tissue, this study demonstrates the different effects of FRD on AT1R expression in different cellular compartments. Elevated blood pressure and decreased antioxidant capacity in visceral fat of fructose-fed rats were accompanied by an increased AT1R level in the plasma membrane, while upregulation of ATRAP and a decrease of nuclear membrane AT1R suggest an increased capacity for attenuation of excessive AT1R signaling and visceral adiposity.
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Affiliation(s)
- Maja Bundalo
- a Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade, Serbia
| | - Ana Djordjevic
- b Department of Biochemistry, Institute for Biological Research "Siniša Stanković", University of Belgrade, 142 Despot Stefan Blvd., 11000 Belgrade, Serbia
| | - Biljana Bursac
- b Department of Biochemistry, Institute for Biological Research "Siniša Stanković", University of Belgrade, 142 Despot Stefan Blvd., 11000 Belgrade, Serbia
| | - Maja Zivkovic
- a Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade, Serbia
| | - Goran Koricanac
- c Laboratory for Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade, Serbia
| | - Aleksandra Stanković
- a Laboratory for Radiobiology and Molecular Genetics, Vinca Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11000 Belgrade, Serbia
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28
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Ferrão FM, Cardoso LHD, Drummond HA, Li XC, Zhuo JL, Gomes DS, Lara LS, Vieyra A, Lowe J. Luminal ANG II is internalized as a complex with AT 1R/AT 2R heterodimers to target endoplasmic reticulum in LLC-PK 1 cells. Am J Physiol Renal Physiol 2017; 313:F440-F449. [PMID: 28468964 DOI: 10.1152/ajprenal.00261.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 04/18/2017] [Accepted: 04/23/2017] [Indexed: 12/28/2022] Open
Abstract
ANG II has many biological effects in renal physiology, particularly in Ca2+ handling in the regulation of fluid and solute reabsorption. It involves the systemic endocrine renin-angiotensin system (RAS), but tissue and intracrine ANG II are also known. We have shown that ANG II induces heterodimerization of its AT1 and AT2 receptors (AT1R and AT2R) to stimulate sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) activity. Thus, we investigated whether ANG II-AT1R/AT2R complex is formed and internalized, and also examined the intracellular localization of this complex to determine how its effect might be exerted on renal intracrine RAS. Living cell imaging of LLC-PK1 cells, quantification of extracellular ANG II, and use of the receptor antagonists, losartan and PD123319, showed that ANG II is internalized with AT1R/AT2R heterodimers as a complex in a microtubule-dependent and clathrin-independent manner, since colchicine-but not Pitstop2-blocked this process. This result was confirmed by an increase of β-arrestin phosphorylation after ANG II treatment, clathrin-mediated endocytosis being dependent on dephosphorylation of β-arrestin. Internalized ANG II colocalized with an endoplasmic reticulum (ER) marker and increased levels of AT1R, AT2R, and PKCα in ER-enriched membrane fractions. This novel evidence suggests the internalization of an ANG II-AT1/AT2 complex to target ER, where it might trigger intracellular Ca2+ responses.
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Affiliation(s)
- Fernanda M Ferrão
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiza H D Cardoso
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Heather A Drummond
- Department of Physiology and Biophysics and the Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Xiao C Li
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Jia L Zhuo
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Dayene S Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lucienne S Lara
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and.,National Institute of Science and Technology for Regenerative Medicine, Rio de Janeiro, Brazil
| | - Jennifer Lowe
- Laboratório de Físico-Química Biológica Aída Hassón-Voloch, Instituto de Biofísica Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; .,Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and
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29
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Tadevosyan A, Xiao J, Surinkaew S, Naud P, Merlen C, Harada M, Qi X, Chatenet D, Fournier A, Allen BG, Nattel S. Intracellular Angiotensin-II Interacts With Nuclear Angiotensin Receptors in Cardiac Fibroblasts and Regulates RNA Synthesis, Cell Proliferation, and Collagen Secretion. J Am Heart Assoc 2017; 6:e004965. [PMID: 28381466 PMCID: PMC5533010 DOI: 10.1161/jaha.116.004965] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/16/2017] [Indexed: 02/01/2023]
Abstract
BACKGROUND Cardiac fibroblasts play important functional and pathophysiological roles. Intracellular ("intracrine") angiotensin-II (Ang-II) signaling regulates intercellular communication, excitability, and gene expression in cardiomyocytes; however, the existence and role of intracrine Ang-II signaling in cardiac fibroblasts is unstudied. Here, we evaluated the localization of Ang-II receptors on atrial fibroblast nuclei and associated intracrine effects of potential functional significance. METHODS AND RESULTS Immunoblots of subcellular protein-fractions from isolated canine atrial fibroblasts indicated the presence of nuclear Ang-II type 1 receptors (AT1Rs) and Ang-II type 2 receptors (AT2Rs). Fluorescein isothiocyanate-Ang-II binding displaceable by AT1R- and AT2R-blockers was present on isolated fibroblast nuclei. G-protein subunits, including Gαq/11, Gαi/3, and Gβ, were observed in purified fibroblast nuclear fractions by immunoblotting and intact-fibroblast nuclei by confocal immunocytofluorescence microscopy. Nuclear AT1Rs and AT2Rs regulated de novo RNA synthesis ([α32P]UTP incorporation) via IP3R- and NO-dependent pathways, respectively. In intact cultured fibroblasts, intracellular Ang-II release by photolysis of a membrane-permeable caged Ang-II analog led to IP3R-dependent nucleoplasmic Ca2+-liberation, with IP3R3 being the predominant nuclear isoform. Intracellular Ang-II regulated fibroblast proliferation ([3H]thymidine incorporation), collagen-1A1 mRNA-expression, and collagen secretion. Intracellular Ang-II and nuclear AT1R protein levels were significantly increased in a heart failure model in which atrial fibrosis underlies atrial fibrillation. CONCLUSIONS Fibroblast nuclei possess AT1R and AT2R binding sites that are coupled to intranuclear Ca2+-mobilization and NO liberation, respectively. Intracellular Ang-II signaling regulates fibroblast proliferation, collagen gene expression, and collagen secretion. Heart failure upregulates Ang-II intracrine signaling-components in atrial fibroblasts. These results show for the first time that nuclear angiotensin-II receptor activation and intracrine Ang-II signaling control fibroblast function and may have pathophysiological significance.
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MESH Headings
- Angiotensin II/physiology
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Angiotensin II Type 2 Receptor Blockers/pharmacology
- Animals
- Calcium/metabolism
- Cell Nucleus/metabolism
- Cell Proliferation
- Collagen/metabolism
- Collagen Type I/genetics
- Disease Models, Animal
- Dogs
- Fibroblasts/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/metabolism
- GTP-Binding Protein beta Subunits/metabolism
- Heart Atria/cytology
- Heart Failure/metabolism
- Immunoblotting
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Microscopy, Fluorescence
- Nitric Oxide/metabolism
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/metabolism
- Transcription, Genetic
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Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Jiening Xiao
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Sirirat Surinkaew
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Patrice Naud
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Clémence Merlen
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - Masahide Harada
- Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Xiaoyan Qi
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
| | - David Chatenet
- Institut National de la Recherche Scientifique-Institut Armand Frappier, Laval, Québec, Canada
| | - Alain Fournier
- Institut National de la Recherche Scientifique-Institut Armand Frappier, Laval, Québec, Canada
| | - Bruce G Allen
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Quebec, Canada
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Duisburg, Germany
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30
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Husser D, Büttner P, Ueberham L, Dinov B, Sommer P, Arya A, Hindricks G, Bollmann A. Genomic Contributors to Rhythm Outcome of Atrial Fibrillation Catheter Ablation - Pathway Enrichment Analysis of GWAS Data. PLoS One 2016; 11:e0167008. [PMID: 27870913 PMCID: PMC5117760 DOI: 10.1371/journal.pone.0167008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/07/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Left atrial enlargement and persistent atrial fibrillation (AF) are well-known predictors for arrhythmia recurrence after AF catheter ablation (LRAF). In this study, by using pathway enrichment analysis of GWAS data, we tested the hypothesis that genetic pathways associated with these phenotypes are also associated with LRAF. METHODS Samples from 660 patients with paroxysmal (n = 370) or persistent AF (n = 290) undergoing de-novo AF catheter ablation were genotyped for ~1,000,000 SNPs. SNPs found to be significantly associated with left atrial diameter (LAD) or AF type were used for gene-based association tests in a systematic biological Knowledge-based mining system for Genome-wide Genetic studies (KGG). Associated genes were tested for pathway enrichment using WEB-based Gene SeT AnaLysis Toolkit (WebGestalt), the Gene Annotation Tool to Help Explain Relationships (GATHER) and the databases provided by Kyoto Encyclopedia of Genes and Genomes (KEGG). In a second step, the association of consistently enriched pathways and LRAF was tested. RESULTS By using sequential 7-day Holter ECGs, LRAF between 3 and 12 months was observed in 48% and was associated with LAD (B = 1.801, 95% CI 0.760-2.841, p = 1.0E-3) and persistent AF (OR = 2.1; 95% CI 1.567-2.931, p = 2.0E-6). WebGestalt (adj. p = 2.7E-22) and GATHER (adj. p = 5.2E-3) identified the calcium signaling pathway (hsa04020) as the only consistently enriched pathway for LAD, while the extracellular matrix (ECM) -receptor interaction pathway (hsa04512) was the only consistently enriched pathway for AF type (adj. p = 2.1E-15 in WebGestalt; adj. p = 9.3E-4 in GATHER). Both calcium signaling (adj. p = 2.2E-17 in WebGestalt; adj. p = 2.9E-2 in GATHER) and ECM-receptor interaction (adj. p = 1.2E-10 in WebGestalt; adj. p = 2.9E-2 in GATHER) were significantly associated with LRAF. CONCLUSIONS Calcium signaling and ECM-receptor interaction pathways are associated with LAD and AF type and, in turn, with LRAF. Future and larger studies are necessary to replicate and apply these findings.
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Affiliation(s)
- Daniela Husser
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
- * E-mail:
| | - Petra Büttner
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Laura Ueberham
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Borislav Dinov
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Philipp Sommer
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Arash Arya
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Gerhard Hindricks
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Leipzig, Germany
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31
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Husser D, Ueberham L, Dinov B, Kosiuk J, Kornej J, Hindricks G, Shoemaker MB, Roden DM, Bollmann A, Büttner P. Genomic contributors to atrial electroanatomical remodeling and atrial fibrillation progression: Pathway enrichment analysis of GWAS data. Sci Rep 2016; 6:36630. [PMID: 27857207 PMCID: PMC5114680 DOI: 10.1038/srep36630] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 10/11/2016] [Indexed: 12/18/2022] Open
Abstract
In atrial fibrillation (AF), left atrial diameter (LAD) and low voltage area (LVA) are intermediate phenotypes that are associated with AF type and progression. In this study, we tested the hypothesis, that these phenotypes share common, genetically-determined pathways using pathway enrichment analysis of GWAS data. Samples from 660 patients with paroxysmal (n = 370) or persistent AF (n = 290) were genotyped for ~1,000,000 SNPs. SNPs found significantly associated with LAD, LVA or AF type were used for gene-based association tests in a systematic biological Knowledge-based mining system for Genome-wide Genetic studies (KGG). Associated genes were tested for pathway enrichment using two enrichment tools (WebGestalt and GATHER) and the databases provided by Kyoto Encyclopedia of Genes and Genomes. The calcium signaling pathway (hsa04020) was the only pathway that reached statistical significance for LAD and LVA in both enrichment tools and was also significantly associated with AF type. Within this pathway, there were 39 genes (i.e. CACNA1C, RyR2) that were associated with LAD, LVA and AF type. In conclusion, there is a genomic contribution to electroanatomical remodeling (LAD, LVA) and AF type via the calcium signaling pathway. Future and larger studies are necessary to replicate and apply these findings.
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Affiliation(s)
- Daniela Husser
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Laura Ueberham
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Borislav Dinov
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Jedrzej Kosiuk
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Jelena Kornej
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Gerhard Hindricks
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | | | - Dan M Roden
- Department of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
| | - Petra Büttner
- Department of Electrophysiology, Heart Center Leipzig, Leipzig University, Germany
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32
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Morinelli TA, Luttrell LM, Strungs EG, Ullian ME. Angiotensin II receptors and peritoneal dialysis-induced peritoneal fibrosis. Int J Biochem Cell Biol 2016; 77:240-50. [PMID: 27167177 PMCID: PMC5038354 DOI: 10.1016/j.biocel.2016.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 12/22/2022]
Abstract
The vasoactive hormone angiotensin II initiates its major hemodynamic effects through interaction with AT1 receptors, a member of the class of G protein-coupled receptors. Acting through its AT1R, angiotensin II regulates blood pressure and renal salt and water balance. Recent evidence points to additional pathological influences of activation of AT1R, in particular inflammation, fibrosis and atherosclerosis. The transcription factor nuclear factor κB, a key mediator in inflammation and atherosclerosis, can be activated by angiotensin II through a mechanism that may involve arrestin-dependent AT1 receptor internalization. Peritoneal dialysis is a therapeutic modality for treating patients with end-stage kidney disease. The effectiveness of peritoneal dialysis at removing waste from the circulation is compromised over time as a consequence of peritoneal dialysis-induced peritoneal fibrosis. The non-physiological dialysis solution used in peritoneal dialysis, i.e. highly concentrated, hyperosmotic glucose, acidic pH as well as large volumes infused into the peritoneal cavity, contributes to the development of fibrosis. Numerous trials have been conducted altering certain components of the peritoneal dialysis fluid in hopes of preventing or delaying the fibrotic response with limited success. We hypothesize that structural activation of AT1R by hyperosmotic peritoneal dialysis fluid activates the internalization process and subsequent signaling through the transcription factor nuclear factor κB, resulting in the generation of pro-fibrotic/pro-inflammatory mediators producing peritoneal fibrosis.
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Affiliation(s)
- Thomas A Morinelli
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States.
| | - Louis M Luttrell
- Division of Endocrinology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, United States
| | - Erik G Strungs
- Division of Endocrinology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Michael E Ullian
- Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC 29425, United States; Research Service of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, United States
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Wilson BA, Nautiyal M, Gwathmey TM, Rose JC, Chappell MC. Evidence for a mitochondrial angiotensin-(1-7) system in the kidney. Am J Physiol Renal Physiol 2016; 310:F637-F645. [PMID: 26697984 PMCID: PMC4824145 DOI: 10.1152/ajprenal.00479.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/10/2015] [Indexed: 11/22/2022] Open
Abstract
Evidence for an intracellular renin-angiotensin system (RAS) in various cell organelles now includes the endoplasmic reticulum, nucleus, and mitochondria (Mito). Indeed, angiotensin (ANG) AT1 and AT2 receptor subtypes were functionally linked to Mito respiration and nitric oxide production, respectively, in previous studies. We undertook a biochemical analysis of the Mito RAS from male and female sheep kidney cortex. Mito were isolated by differential centrifugation followed by a discontinuous Percoll gradient and were coenriched in Mito membrane markers VDAC and ATP synthase, but not β-actin or cathepsin B. Two distinct renin antibodies identified a 37-kDa protein band in Mito; angiotensinogen (Aogen) conversion was abolished by the inhibitor aliskiren. Mito Aogen was detected by an Aogen antibody to an internal sequence of the protein, but not with an antibody directed against the ANG I N terminus. ANG peptides were quantified by three direct RIAs; mitochondrial ANG II and ANG-(1-7) contents were higher compared with ANG I (23 ± 8 and 58 ± 17 vs. 2 ± 1 fmol/mg protein; P < 0.01, n = 3). 125I-ANG I metabolism primarily revealed the formation of 125I-ANG-(1-7) in Mito that reflects the endopeptidases neprilysin and thimet oligopeptidase. Last, immunoblot studies utilizing the ANG-(1-7)/Mas receptor antibody revealed the protein in isolated Mito from sheep renal cortex. Collectively, the current data demonstrate that Mito actively metabolize the RAS precursor protein Aogen, suggesting that ANG-(1-7) may be generated within Mito to establish an intramitochondrial RAS tone and contribute to renal mitochondrial function.
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Affiliation(s)
- Bryan A Wilson
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Manisha Nautiyal
- Division of Endocrinology, Diabetes, and Metabolism, University of Florida, Gainesville, Florida
| | - TanYa M Gwathmey
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - James C Rose
- Department of Obstetrics and Gynecology, Wake Forest University School of Medicine, Winston-Salem, North Carolina; and
| | - Mark C Chappell
- Hypertension and Vascular Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina;
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Abstract
Calcium (Ca) is a universal second messenger involved in the regulation of various cellular processes, including electrical signaling, contraction, secretion, memory, gene transcription, and cell death. In heart, Ca governs cardiomyocyte contraction, is central in electrophysiological properties, and controls major signaling pathway implicated in gene transcription. How cardiomyocytes decode Ca signal to regulate gene expression without interfering with, or being controlled by, "contractile" Ca that floods the entire cytosol during each heartbeat is still elusive. In this review, we summarize recent findings on nuclear Ca regulation and its downstream signaling in cardiomyocytes. We will address difficulties in reliable quantification of nuclear Ca fluxes and discuss its role in the development and progression of cardiac hypertrophy and heart failure. We also point out key open questions to stimulate future work.
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Abstract
Although convention dictates that G protein-coupled receptors localize to and signal at the plasma membrane, accumulating evidence suggests that G protein-coupled receptors localize to and signal at intracellular membranes, most notably the nucleus. In fact, there is now significant evidence indicating that endogenous alpha-1 adrenergic receptors (α1-ARs) localize to and signal at the nuclei in adult cardiac myocytes. Cumulatively, the data suggest that α1-ARs localize to the inner nuclear membrane, activate intranuclear signaling, and regulate physiologic function in adult cardiac myocytes. Although α1-ARs signal through Gαq, unlike other Gq-coupled receptors, α1-ARs mediate important cardioprotective functions including adaptive/physiologic hypertrophy, protection from cell death (survival signaling), positive inotropy, and preconditioning. Also unlike other Gq-coupled receptors, most, if not all, functional α1-ARs localize to the nuclei in adult cardiac myocytes, as opposed to the sarcolemma. Together, α1-AR nuclear localization and cardioprotection might suggest a novel model for compartmentalization of Gq-coupled receptor signaling in which nuclear Gq-coupled receptor signaling is cardioprotective.
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Abstract
According to the standard model of G protein-coupled receptor (GPCR) signaling, GPCRs are localized to the cell membrane where they respond to extracellular signals. Stimulation of GPCRs leads to the activation of heterotrimeric G proteins and their intracellular signaling pathways. However, this model fails to accommodate GPCRs, G proteins, and their downstream effectors that are found on the nuclear membrane or in the nucleus. Evidence from isolated nuclei indicates the presence of GPCRs on the nuclear membrane that can activate similar G protein-dependent signaling pathways in the nucleus as at the cell surface. These pathways also include activation of cyclic adenosine monophosphate, calcium and nitric oxide synthase signaling in cardiomyocytes. In addition, a number of distinct heterotrimeric and monomeric G proteins have been found in the nucleus of various cell types. This review will focus on understanding the function of nuclear G proteins with a focus on cardiac signaling where applicable.
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Abstract
G protein-coupled receptors (GPCRs) play key physiological roles and represent a significant target for drug development. However, historically, drugs were developed with the understanding that GPCRs as a therapeutic target exist solely on cell surface membranes. More recently, GPCRs have been detected on intracellular membranes, including the nuclear membrane, and the concept that intracellular GPCRs are functional is become more widely accepted. Nuclear GPCRs couple to effectors and regulate signaling pathways, analogous to their counterparts at the cell surface, but may serve distinct biological roles. Hence, the physiological responses mediated by GPCR ligands, or pharmacological agents, result from the integration of their actions at extracellular and intracellular receptors. The net effect depends on the ability of a given ligand or drug to access intracellular receptors, as dictated by its structure, lipophilic properties, and affinity for nuclear receptors. This review will discuss angiotensin II, endothelin, and β-adrenergic receptors located on the nuclear envelope in cardiac cells in terms of their origin, activation, and role in cardiovascular function and pathology.
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Wanka H, Staar D, Lutze P, Peters B, Hildebrandt J, Beck T, Bäumgen I, Albers A, Krieg T, Zimmermann K, Sczodrok J, Schäfer S, Hoffmann S, Peters J. Anti-necrotic and cardioprotective effects of a cytosolic renin isoform under ischemia-related conditions. J Mol Med (Berl) 2015; 94:61-9. [DOI: 10.1007/s00109-015-1321-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 12/31/2022]
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Tadevosyan A, Villeneuve LR, Fournier A, Chatenet D, Nattel S, Allen BG. Caged ligands to study the role of intracellular GPCRs. Methods 2015. [PMID: 26196333 DOI: 10.1016/j.ymeth.2015.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In addition to cell surface membranes, numerous G protein-coupled receptors (GPCRs) are located on intracellular membranes including the nuclear envelope. Although the role of numerous GPCRs at the cell surface has been well characterized, the physiological function of these same receptors located on intracellular membranes remains to be determined. Here, we employ a novel caged Ang-II analog, cAng-II, to compare the effects of the activation of cell surface versus intracellular angiotensin receptors in intact cardiomyocytes. When added extracellularly to HEK 293 cells, Ang-II and photolysed cAng-II increased ERK1/2 phosphorylation (via AT1R) and cGMP production (AT2R). In contrast unphotolysed cAng-II did not. Cellular uptake of cAng-II was 6-fold greater than that of Ang-II and comparable to the HIV TAT(48-60) peptide. Intracellular photolysis of cAng-II induced an increase in nucleoplasmic Ca(2+) ([Ca(2+)]n) that was greater than that induced by extracellular application of Ang-II. We conclude that cell-permeable ligands that can access intracellular GPCRs may evoke responses distinct from those with access restricted to the same receptor located on the cell surface.
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Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada
| | | | - Alain Fournier
- INRS-Institut Armand-Frappier, Université du Québec, Canada; Laboratoire International Associé Samuel de Champlain, Canada
| | - David Chatenet
- INRS-Institut Armand-Frappier, Université du Québec, Canada; Laboratoire International Associé Samuel de Champlain, Canada
| | - Stanley Nattel
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada; Department of Pharmacology and Therapeutics, McGill University, Canada.
| | - Bruce G Allen
- Department of Medicine, Université de Montréal, Canada; Montreal Heart Institute, Canada; Department of Pharmacology and Therapeutics, McGill University, Canada; Department of Biochemistry and Molecular Medicine, Université de Montréal, Canada.
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Aztatzi-Aguilar OG, Uribe-Ramírez M, Arias-Montaño JA, Barbier O, De Vizcaya-Ruiz A. Acute and subchronic exposure to air particulate matter induces expression of angiotensin and bradykinin-related genes in the lungs and heart: Angiotensin-II type-I receptor as a molecular target of particulate matter exposure. Part Fibre Toxicol 2015; 12:17. [PMID: 26113123 PMCID: PMC4482198 DOI: 10.1186/s12989-015-0094-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 06/15/2015] [Indexed: 01/03/2023] Open
Abstract
Background Particulate matter (PM) adverse effects on health include lung and heart damage. The renin-angiotensin-aldosterone (RAAS) and kallikrein-kinin (KKS) endocrine systems are involved in the pathophysiology of cardiovascular diseases and have been found to impact lung diseases. The aim of the present study was to evaluate whether PM exposure regulates elements of RAAS and KKS. Methods Sprague–Dawley rats were acutely (3 days) and subchronically (8 weeks) exposed to coarse (CP), fine (FP) or ultrafine (UFP) particulates using a particulate concentrator, and a control group exposed to filtered air (FA). We evaluated the mRNA of the RAAS components At1, At2r and Ace, and of the KKS components B1r, B2r and Klk-1 by RT-PCR in the lungs and heart. The ACE and AT1R protein were evaluated by Western blot, as were HO-1 and γGCSc as indicators of the antioxidant response and IL-6 levels as an inflammation marker. We performed a binding assay to determinate AT1R density in the lung, also the subcellular AT1R distribution in the lungs was evaluated. Finally, we performed a histological analysis of intramyocardial coronary arteries and the expression of markers of heart gene reprogramming (Acta1 and Col3a1). Results The PM fractions induced the expression of RAAS and KKS elements in the lungs and heart in a time-dependent manner. CP exposure induced Ace mRNA expression and regulated its protein in the lungs. Acute and subchronic exposure to FP and UFP induced the expression of At1r in the lungs and heart. All PM fractions increased the AT1R protein in a size-dependent manner in the lungs and heart after subchronic exposure. The AT1R lung protein showed a time-dependent change in subcellular distribution. In addition, the presence of AT1R in the heart was accompanied by a decrease in HO-1, which was concomitant with the induction of Acta1 and Col3a1 and the increment of IL-6. Moreover, exposure to all PM fractions increased coronary artery wall thickness. Conclusion We demonstrate that exposure to PM induces the expression of RAAS and KKS elements, including AT1R, which was the main target in the lungs and the heart.
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Affiliation(s)
- Octavio Gamaliel Aztatzi-Aguilar
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional, 2508, México D. F, CP. 07360, Mexico.
| | - Marisela Uribe-Ramírez
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional, 2508, México D. F, CP. 07360, Mexico.
| | - José Antonio Arias-Montaño
- Departamento de Fisiología, Neurociencias y Biofísica, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional, 2508, México D. F, C.P. 07360, Mexico.
| | - Olivier Barbier
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional, 2508, México D. F, CP. 07360, Mexico.
| | - Andrea De Vizcaya-Ruiz
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional, 2508, México D. F, CP. 07360, Mexico.
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Tadevosyan A, Allen BG, Nattel S. Isolation and study of cardiac nuclei from canine myocardium and adult ventricular myocytes. Methods Mol Biol 2015; 1234:69-80. [PMID: 25304349 DOI: 10.1007/978-1-4939-1755-6_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The nuclear envelope encloses the genome as well as the molecular machinery responsible for both the replication and transcription of DNA as well as the maturation of nascent RNA. Recent studies ascribe a growing number of functions to the nuclear membrane, in addition to sequestering the DNA, through receptors and their effectors, ion channels, as well as ion pumps and transporters located within the nuclear membrane itself. Despite the obvious structural and functional importance of the nucleus, certain aspects remain poorly understood due to the challenges associated with its accessibility in vivo, as well as isolating nuclei intact and with sufficient purity from cardiac cells to permit studies in vitro. Here, we present a detailed protocol for isolation of intact nuclei from both myocardial tissue and freshly isolated adult ventricular cardiomyocytes. These methods are based on partial permeabilization of plasma membrane with digitonin and cell disruption, followed by differential and discontinuous sucrose density centrifugation. These preparations provide for rapid separation of nonnuclear membranes and cytosol from nuclei.
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Affiliation(s)
- Artavazd Tadevosyan
- Montreal Heart Institute, 5000 Belanger Street, Montreal, QC, Canada, H1T 1C8
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Zawada WM, Mrak RE, Biedermann J, Palmer QD, Gentleman SM, Aboud O, Griffin WST. Loss of angiotensin II receptor expression in dopamine neurons in Parkinson's disease correlates with pathological progression and is accompanied by increases in Nox4- and 8-OH guanosine-related nucleic acid oxidation and caspase-3 activation. Acta Neuropathol Commun 2015; 3:9. [PMID: 25645462 PMCID: PMC4359535 DOI: 10.1186/s40478-015-0189-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/20/2015] [Indexed: 12/22/2022] Open
Abstract
Background In rodent models of Parkinson’s disease (PD), dopamine neuron loss is accompanied by increased expression of angiotensin II (AngII), its type 1 receptor (AT1), and NADPH oxidase (Nox) in the nigral dopamine neurons and microglia. AT1 blockers (ARBs) stymie such oxidative damage and neuron loss. Whether changes in the AngII/AT1/Nox4 axis contribute to Parkinson neuropathogenesis is unknown. Here, we studied the distribution of AT1 and Nox4 in dopamine neurons in two nigral subregions: the less affected calbindin-rich matrix and the first-affected calbindin-poor nigrosome 1 of three patients, who were clinically asymptomatic, but had nigral dopamine cell loss and Braak stages consistent with a neuropathological diagnosis of PD (prePD). For comparison, five clinically- and neuropathologically-confirmed PD patients and seven age-matched control patients (AMC) were examined. Results AT1 and Nox4 immunoreactivity was noted in dopamine neurons in both the matrix and the nigrosome 1. The total cellular levels of AT1 in surviving dopamine neurons in the matrix and nigrosome 1 declined from AMC>prePD>PD, suggesting that an AngII/AT1/Nox4 axis orders neurodegenerative progression. In this vein, the loss of dopamine neurons was paralleled by a decline in total AT1 per surviving dopamine neuron. Similarly, AT1 in the nuclei of surviving neurons in the nigral matrix declined with disease progression, i.e., AMC>prePD>PD. In contrast, in nigrosome 1, the expression of nuclear AT1 was unaffected and similar in all groups. The ratio of nuclear AT1 to total AT1 (nuclear + cytoplasmic + membrane) in dopamine neurons increased stepwise from AMC to prePD to PD. The proportional increase in nuclear AT1 in dopamine neurons in nigrosome 1 of prePD and PD patients was accompanied by elevated nuclear expression of Nox4, oxidative damage to DNA, and caspase-3-mediated cell loss. Conclusions Our observations are consistent with the idea that AngII/AT1/Nox4 axis-mediated oxidative stress gives rise to the dopamine neuron dysfunction and loss characteristic of the neuropathological and clinical manifestations of PD and suggest that the chance for a neuron to survive increases in association with lower total as well as nuclear AT1 expression. Our results support the need for further evaluation of ARBs as disease-modifying agents in PD.
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Tadevosyan A, Létourneau M, Folch B, Doucet N, Villeneuve LR, Mamarbachi AM, Pétrin D, Hébert TE, Fournier A, Chatenet D, Allen BG, Nattel S. Photoreleasable ligands to study intracrine angiotensin II signalling. J Physiol 2015; 593:521-39. [PMID: 25433071 DOI: 10.1113/jphysiol.2014.279109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 11/20/2014] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS The renin-angiotensin system plays a key role in cardiovascular physiology and its overactivation has been implicated in the pathogenesis of several major cardiovascular diseases. There is growing evidence that angiotensin II (Ang-II) may function as an intracellular peptide to activate intracellular/nuclear receptors and their downstream signalling effectors independently of cell surface receptors. Current methods used to study intracrine Ang-II signalling are limited to indirect approaches because of a lack of selective intracellularly-acting probes. Here, we present novel photoreleasable Ang-II analogues used to probe intracellular actions with spatial and temporal precision. The photorelease of intracellular Ang-II causes nuclear and cytosolic calcium mobilization and initiates the de novo synthesis of RNA in cardiac cells, demonstrating the application of the method. ABSTRACT Several lines of evidence suggest that intracellular angiotensin II (Ang-II) contributes to the regulation of cardiac contractility, renal salt reabsorption, vascular tone and metabolism; however, work on intracrine Ang-II signalling has been limited to indirect approaches because of a lack of selective intracellularly-acting probes. Here, we aimed to synthesize and characterize cell-permeant Ang-II analogues that are inactive without uncaging, but release active Ang-II upon exposure to a flash of UV-light, and act as novel tools for use in the study of intracrine Ang-II physiology. We prepared three novel caged Ang-II analogues, [Tyr(DMNB)(4)]Ang-II, Ang-II-ODMNB and [Tyr(DMNB)(4)]Ang-II-ODMNB, based upon the incorporation of the photolabile moiety 4,5-dimethoxy-2-nitrobenzyl (DMNB). Compared to Ang-II, the caged Ang-II analogues showed 2-3 orders of magnitude reduced affinity toward both angiotensin type-1 (AT1R) and type-2 (AT2R) receptors in competition binding assays, and greatly-reduced potency in contraction assays of rat thoracic aorta. After receiving UV-irradiation, all three caged Ang-II analogues released Ang-II and potently induced the contraction of rat thoracic aorta. [Tyr(DMNB)(4)]Ang-II showed the most rapid photolysis upon UV-irradiation and was the focus of subsequent characterization. Whereas Ang-II and photolysed [Tyr(DMNB)(4)]Ang-II increased ERK1/2 phosphorylation (via AT1R) and cGMP production (AT2R), caged [Tyr(DMNB)(4)]Ang-II did not. Cellular uptake of [Tyr(DMNB)(4)]Ang-II was 4-fold greater than that of Ang-II and significantly greater than uptake driven by the positive-control HIV TAT(48-60) peptide. Intracellular photolysis of [Tyr(DMNB)(4)]Ang-II induced an increase in nucleoplasmic Ca(2+) ([Ca(2+)]n), and initiated 18S rRNA and nuclear factor kappa B mRNA synthesis in adult cardiac cells. We conclude that caged Ang-II analogues represent powerful new tools for use in the selective study of intracrine signalling via Ang-II.
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Affiliation(s)
- Artavazd Tadevosyan
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada; Montreal Heart Institute, Montréal, Québec, Canada
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Alpha-1-adrenergic receptors in heart failure: the adaptive arm of the cardiac response to chronic catecholamine stimulation. J Cardiovasc Pharmacol 2014; 63:291-301. [PMID: 24145181 DOI: 10.1097/fjc.0000000000000032] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alpha-1-adrenergic receptors (ARs) are G protein-coupled receptors activated by catecholamines. The alpha-1A and alpha-1B subtypes are expressed in mouse and human myocardium, whereas the alpha-1D protein is found only in coronary arteries. There are far fewer alpha-1-ARs than beta-ARs in the nonfailing heart, but their abundance is maintained or increased in the setting of heart failure, which is characterized by pronounced chronic elevation of catecholamines and beta-AR dysfunction. Decades of evidence from gain and loss-of-function studies in isolated cardiac myocytes and numerous animal models demonstrate important adaptive functions for cardiac alpha-1-ARs to include physiological hypertrophy, positive inotropy, ischemic preconditioning, and protection from cell death. Clinical trial data indicate that blocking alpha-1-ARs is associated with incident heart failure in patients with hypertension. Collectively, these findings suggest that alpha-1-AR activation might mitigate the well-recognized toxic effects of beta-ARs in the hyperadrenergic setting of chronic heart failure. Thus, exogenous cardioselective activation of alpha-1-ARs might represent a novel and viable approach to the treatment of heart failure.
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Wu SC, Dahl EF, Wright CD, Cypher AL, Healy CL, O'Connell TD. Nuclear localization of a1A-adrenergic receptors is required for signaling in cardiac myocytes: an “inside-out” a1-AR signaling pathway. J Am Heart Assoc 2014; 3:e000145. [PMID: 24772522 PMCID: PMC4187477 DOI: 10.1161/jaha.113.000145] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Recent studies indicate that α1‐adrenergic receptors (α1‐ARs) are cardioprotective by preventing cardiac myocyte death and augmenting contractility in heart failure. Although G‐protein‐coupled receptors are assumed to localize to and signal at the plasma membrane, we previously demonstrated that endogenous α1‐ARs localize to the nuclei in adult cardiac myocytes. However, the functional consequence of this nuclear localization remains unclear. Here, we attempted to reconcile nuclear localization of α1‐ARs with their physiologic function by examining α1‐AR‐induced contractility in adult cardiac myocytes. Methods and Results By measuring shortening in unloaded, cultured adult cardiac myocytes, we found that the α1A‐subtype regulated contractility through phosphorylation of cardiac troponin I (cTnI) at the protein kinase C (PKC) site, threonine 144. Reconstitution of an α1A‐subtype nuclear localization mutant in cardiac myocytes lacking α1‐ARs failed to rescue nuclear α1A‐mediated phosphorylation of cTnI and myocyte contractility. Leptomycin B, the nuclear export inhibitor, also blocked α1A‐mediated phosphorylation of cTnI. These data indicate that α1‐AR signaling originates in the nucleus. Consistent with these observations, we localized the α1A‐subtype to the inner nuclear membrane, identified PKCα, δ, and ε in the nucleus, and found that α1‐ARs activate PKCδ in nuclei isolated from adult cardiac myocytes. Finally, we found that a PKCδ nuclear localization mutant blunted α1‐induced phosphorylation of cTnI. Conclusions Together, our data identify a novel, “inside‐out” nuclear α1A‐subtype/PKCδ/cTnI‐signaling pathway that regulates contractile function in adult cardiac myocytes. Importantly, these data help resolve the discrepancy between nuclear localization of α1‐ARs and α1‐AR‐mediated physiologic function.
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Affiliation(s)
- Steven C. Wu
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Erika F. Dahl
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Casey D. Wright
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
- Novartis Animal Health US, Inc, 1447140th St, Larchwood, IA 51241
| | - Andrew L. Cypher
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
- Novartis Animal Health US, Inc, 1447140th St, Larchwood, IA 51241
| | - Chastity L. Healy
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Timothy D. O'Connell
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
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Jong YJI, Sergin I, Purgert CA, O'Malley KL. Location-dependent signaling of the group 1 metabotropic glutamate receptor mGlu5. Mol Pharmacol 2014; 86:774-85. [PMID: 25326002 DOI: 10.1124/mol.114.094763] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although G protein-coupled receptors are primarily known for converting extracellular signals into intracellular responses, some receptors, such as the group 1 metabotropic glutamate receptor, mGlu5, are also localized on intracellular membranes where they can mediate both overlapping and unique signaling effects. Thus, besides "ligand bias," whereby a receptor's signaling modality can shift from G protein dependence to independence, canonical mGlu5 receptor signaling can also be influenced by "location bias" (i.e., the particular membrane and/or cell type from which it signals). Because mGlu5 receptors play important roles in both normal development and in disorders such as Fragile X syndrome, autism, epilepsy, addiction, anxiety, schizophrenia, pain, dyskinesias, and melanoma, a large number of drugs are being developed to allosterically target this receptor. Therefore, it is critical to understand how such drugs might be affecting mGlu5 receptor function on different membranes and in different brain regions. Further elucidation of the site(s) of action of these drugs may determine which signal pathways mediate therapeutic efficacy.
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Affiliation(s)
- Yuh-Jiin I Jong
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Ismail Sergin
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Carolyn A Purgert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
| | - Karen L O'Malley
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri
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Merlen C, Ledoux J. Single-cell microinjection coupled to confocal microscopy to characterize nuclear membrane receptors in freshly isolated cardiomyocytes. Methods Mol Biol 2014; 1234:9-16. [PMID: 25304344 DOI: 10.1007/978-1-4939-1755-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Lipid bilayers, such as the plasma membrane and nuclear envelope, serve as effective cellular barriers to ions and macromolecules, thus allowing regulated access to subcellular compartments including the cytoplasm and nucleus, respectively. Of course, these barriers are semipermeable and a wide variety of proteins including transporters, ion exchangers, pumps, and ion channels are required to permit access as well as establish and maintain molecular and ionic gradients across membranes. However, some experimental designs, such as specifically targeting intracellular receptors, require the administration of membrane-impermeable molecules directly into live cells. The microinjection technique described in this chapter is an efficient, technically simple, and reliable approach that can be used to introduce macromolecules into intracellular compartments while maintaining the integrity of the plasma membrane itself.
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Affiliation(s)
- Clémence Merlen
- Montreal Heart Institute, 5000 Belanger Street, Montreal, QC, Canada, H1T 1C8
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Ibarra C, Vicencio JM, Varas-Godoy M, Jaimovich E, Rothermel BA, Uhlén P, Hill JA, Lavandero S. An integrated mechanism of cardiomyocyte nuclear Ca(2+) signaling. J Mol Cell Cardiol 2014; 75:40-8. [PMID: 24997440 PMCID: PMC4626248 DOI: 10.1016/j.yjmcc.2014.06.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 06/11/2014] [Accepted: 06/26/2014] [Indexed: 01/05/2023]
Abstract
In cardiomyocytes, Ca(2+) plays a central role in governing both contraction and signaling events that regulate gene expression. Current evidence indicates that discrimination between these two critical functions is achieved by segregating Ca(2+) within subcellular microdomains: transcription is regulated by Ca(2+) release within nuclear microdomains, and excitation-contraction coupling is regulated by cytosolic Ca(2+). Accordingly, a variety of agonists that control cardiomyocyte gene expression, such as endothelin-1, angiotensin-II or insulin-like growth factor-1, share the feature of triggering nuclear Ca(2+) signals. However, signaling pathways coupling surface receptor activation to nuclear Ca(2+) release, and the phenotypic responses to such signals, differ between agonists. According to earlier hypotheses, the selective control of nuclear Ca(2+) signals by activation of plasma membrane receptors relies on the strategic localization of inositol trisphosphate receptors at the nuclear envelope. There, they mediate Ca(2+) release from perinuclear Ca(2+) stores upon binding of inositol trisphosphate generated in the cytosol, which diffuses into the nucleus. More recently, identification of such receptors at nuclear membranes or perinuclear sarcolemmal invaginations has uncovered novel mechanisms whereby agonists control nuclear Ca(2+) release. In this review, we discuss mechanisms for the selective control of nuclear Ca(2+) signals with special focus on emerging models of agonist receptor activation.
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Affiliation(s)
- Cristián Ibarra
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development, AstraZeneca R&D, Mölndal, Sweden.
| | - Jose Miguel Vicencio
- Hatter Cardiovascular Institute, University College London, London, United Kingdom
| | - Manuel Varas-Godoy
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Enrique Jaimovich
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Beverly A Rothermel
- Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Per Uhlén
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Joseph A Hill
- Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sergio Lavandero
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile; Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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Demurtas P, Corrias M, Zucca I, Maxia C, Piras F, Sirigu P, Perra MT. Angiotensin II: immunohistochemical study in Sardinian pterygium. Eur J Histochem 2014; 58:2426. [PMID: 25308851 PMCID: PMC4194399 DOI: 10.4081/ejh.2014.2426] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/25/2014] [Accepted: 07/02/2014] [Indexed: 11/22/2022] Open
Abstract
The Angiotensin II (Ang II) is the principal effector peptide of the RAS system. It has a pleiotropic effect and, beside its physiological role, it has the property to stimulate angiogenesis and activate multiple signalling pathways related to cell proliferation. The purpose of the study was to determinate the Ang II expression and localization in Sardinian pterygium and normal conjunctiva by immunohistochemistry, and its possible involvement in the development and progression of the disease. Twenty-three pterygiums and eleven normal conjunctiva specimens obtained from Sardinian patients, were processed for paraffin embedding and assessed for the immunohistochemi-cal revelation of Ang II. Significant Ang II expression was identified in pterygium and conjunctiva. Particularly, thirteen pterygium specimens (n=13) displayed exclusively moderate to strong nuclear staining; some specimens (n=5) showed exclusively a moderate cytoplasmic immunoreactivity, and few specimens (n=2) displayed moderate to strong immunoreactivity in both cytoplasm and nucleus. Only 3 specimens were negative. Statistical significance difference in respect of nuclear and cytoplasmic localization was observed between normal conjunctiva and pterygium (P=0.020). The results showed a predominant intranuclear localization of Ang II in pterygium epithelial cells, in spite of conjunctiva that mainly showed cytoplasmic localization. These findings suggest a possible role for Ang II in the development and/or progression of pterygium mediated by the activation of local RAS system.
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MAS promoter regulation: a role for Sry and tyrosine nitration of the KRAB domain of ZNF274 as a feedback mechanism. Clin Sci (Lond) 2014; 126:727-38. [PMID: 24128372 DOI: 10.1042/cs20130385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ACE2 (angiotensin-converting enzyme 2)/Ang-(1-7) [angiotensin-(1-7)]/MAS axis of the RAS (renin-angiotensin system) has emerged as a pathway of interest in treating both cardiovascular disorders and cancer. The MAS protein is known to bind to and be activated by Ang-(1-7); however, the mechanisms of this activation are just starting to be understood. Although there are strong biochemical data regarding the regulation and activation of the AT1R (angiotensin II type 1 receptor) and the AT2R (angiotensin II type 2 receptor), with models of how AngII (angiotensin II) binds each receptor, fewer studies have characterized MAS. In the present study, we characterize the MAS promoter and provide a potential feedback mechanism that could compensate for MAS degradation following activation by Ang-(1-7). Analysis of ENCODE data for the MAS promoter revealed potential epigenetic control by KRAB (Krüppel-associated box)/KAP-1 (KRAB-associated protein-1). A proximal promoter construct for the MAS gene was repressed by the SOX [SRY (sex-determining region on the Y chromosome) box] proteins SRY, SOX2, SOX3 and SOX14, of which SRY is known to interact with the KRAB domain. The KRAB-KAP-1 complex can be tyrosine-nitrated, causing the dissociation of the KAP-1 protein and thus a potential loss of epigenetic control. Activation of MAS can lead to an increase in nitric oxide, suggesting a feedback mechanism for MAS on its own promoter. The results of the present study provide a more complete view of MAS regulation and, for the first time, suggest biochemical outcomes for nitration of the KRAB domain.
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