1
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Khan SM, Martin RD, Bayne A, Pétrin D, Bourque K, Jones-Tabah J, Bouazza C, Blaney J, Lau J, Martins-Cannavino K, Gora S, Zhang A, MacKinnon S, Trieu P, Clarke PBS, Trempe JF, Tanny JC, Hébert TE. Gβγ subunits colocalize with RNA polymerase II and regulate transcription in cardiac fibroblasts. J Biol Chem 2023; 299:103064. [PMID: 36841480 PMCID: PMC10060754 DOI: 10.1016/j.jbc.2023.103064] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/26/2023] Open
Abstract
Gβγ subunits mediate many different signaling processes in various compartments of the cell, including the nucleus. To gain insight into the functions of nuclear Gβγ signaling, we investigated the functional role of Gβγ signaling in the regulation of GPCR-mediated gene expression in primary rat neonatal cardiac fibroblasts. We identified a novel, negative, regulatory role for the Gβ1γ dimer in the fibrotic response. Depletion of Gβ1 led to derepression of the fibrotic response at the mRNA and protein levels under basal conditions and an enhanced fibrotic response after sustained stimulation of the angiotensin II type I receptor. Our genome-wide chromatin immunoprecipitation experiments revealed that Gβ1 colocalized and interacted with RNA polymerase II on fibrotic genes in an angiotensin II-dependent manner. Additionally, blocking transcription with inhibitors of Cdk9 prevented association of Gβγ with transcription complexes. Together, our findings suggest that Gβ1γ is a novel transcriptional regulator of the fibrotic response that may act to restrict fibrosis to conditions of sustained fibrotic signaling. Our work expands the role for Gβγ signaling in cardiac fibrosis and may have broad implications for the role of nuclear Gβγ signaling in other cell types.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andrew Bayne
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada; Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jace Jones-Tabah
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Celia Bouazza
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jacob Blaney
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jenny Lau
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | | | - Sarah Gora
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Andy Zhang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Sarah MacKinnon
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Phan Trieu
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Paul B S Clarke
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jean-François Trempe
- Centre de Recherche en Biologie Structurale, McGill University, Montréal, Québec, Canada
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
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2
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Mazurara GR, Dallagnol JCC, Chatenet D, Allen BG, Hébert TE. The complicated lives of GPCRs in cardiac fibroblasts. Am J Physiol Cell Physiol 2022; 323:C813-C822. [PMID: 35938678 DOI: 10.1152/ajpcell.00120.2022] [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: 11/22/2022]
Abstract
The role of different G protein-coupled receptors (GPCRs) in the cardiovascular system is well understood in cardiomyocytes and vascular smooth muscle cells (VSMCs). In the former, stimulation of Gs-coupled receptors leads to increases in contractility, while stimulation of Gq-coupled receptors modulates cellular survival and hypertrophic responses. In VSMCs, stimulation of GPCRs also modulates contractile and cell growth phenotypes. Here, we will focus on the relatively less well studied effects of GPCRs in cardiac fibroblasts, focusing on key signalling events involved in the activation and differentiation of these cells. We also review the hierarchy of signalling events driving the fibrotic response and the communications between fibroblasts and other cells in the heart. We discuss how such events may be distinct depending on where the GPCRs and their associated signalling machinery are localized in these cells with an emphasis on nuclear membrane-localized receptors. Finally, we explore what such connections between cell surface and nuclear GPCR signalling might mean for cardiac fibrosis.
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Affiliation(s)
- Grace R Mazurara
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Juliana C C Dallagnol
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.,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, Québec, Canada.,Research Center, Montreal Heart Institute, Montreal, Quebec, 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, Québec, Canada
| | - Bruce G Allen
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
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3
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Zhang Y, Yang X, Han C, Wang D, Ma Y, Wei W. Paeoniflorin‑6'O‑benzene sulfonate suppresses fibroblast‑like synoviocytes proliferation and migration in rheumatoid arthritis through regulating GRK2‑Gβγ interaction. Exp Ther Med 2022; 24:523. [DOI: 10.3892/etm.2022.11450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/19/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Yuwen Zhang
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
| | - Xuezhi Yang
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
| | - Chenchen Han
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
| | - Dandan Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
| | - Yang Ma
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
| | - Wei Wei
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti‑inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti‑inflammatory and Immune Medicine, Hefei, Anhui 230032, P.R. China
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4
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Ali DC, Naveed M, Gordon A, Majeed F, Saeed M, Ogbuke MI, Atif M, Zubair HM, Changxing L. β-Adrenergic receptor, an essential target in cardiovascular diseases. Heart Fail Rev 2021; 25:343-354. [PMID: 31407140 DOI: 10.1007/s10741-019-09825-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
β-Adrenergic receptors (βARs) belong to a large family of cell surface receptors known as G protein-coupled receptors (GPCRs). They are coupled to Gs protein (Gαs) for the activation of adenylyl cyclase (AC) yielding cyclic AMP (CAMP), and this provides valuable responses, which can affect the cardiac function such as injury. The binding of an agonist to βAR enhances conformation changes that lead to the Gαs subtype of heterotrimeric G protein which is the AC stimulatory G protein for activation of CAMP in the cells. However, cardiovascular diseases (CVD) have been reported as having an increased rate of death and β1AR, and β2AR are a promising tool that improves the regulatory function in the cardiovascular system (CVS) via signaling. It increases the Gα level, which activates βAR kinase (βARK) that affects and enhances the progression of heart failure (HF) through the activation of cardiomyocyte βARs. We also explained that an increase in GPCR kinases (GRKs) would practically improve the HF pathogenesis and this occurs via the desensitization of βARs, which causes the loss of contractile reserve. The consistency or overstimulation of catecholamines contributes to CVD such as stroke, HF, and cardiac hypertrophy. When there is a decrease in catecholamine responsiveness, it causes aging in old people because the reduction of βAR sensitivity and density in the myocardium enhances downregulation of βARs to AC in the human heart.
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Affiliation(s)
- Daniel Chikere Ali
- Department of Microbiological and Biochemical Pharmacy, School of Life Science, China Pharmaceutical University, Nanjing, 210009, Jiangsu Province, People's Republic of China
| | - Muhammad Naveed
- Department of Clinical Pharmacology, School of Pharmacy, Nanjing Medical University, 211166, Nanjing, Jiangsu Province, People's Republic of China
| | - Andrew Gordon
- Department of Pharmacognosy, School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, Jiangsu Province, People's Republic of China
| | - Fatima Majeed
- Department of Nutrition and Food Hygiene, School of Public Health, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, People's Republic of China
| | - Muhammad Saeed
- Faculty of Animal Production and Technology, The Cholistan University of Veterinary and Animal Sciences, Bahawalpur, 6300, Punjab Province, Pakistan
| | - Michael I Ogbuke
- Department of Pharmacy, School of Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu Province, 210009, People's Republic of China
| | - Muhammad Atif
- Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur, Bahawalpur, 63100, Punjab Province, Pakistan
| | - Hafiz Muhammad Zubair
- Department of Pharmacology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, People's Republic of China
| | - Li Changxing
- Department of Human Anatomy, Medical College of Qinghai University, Xining, 810000, Qinghai Province, People's Republic of China.
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5
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Carlson EL, Karuppagounder V, Pinamont WJ, Yoshioka NK, Ahmad A, Schott EM, Le Bleu HK, Zuscik MJ, Elbarbary RA, Kamal F. Paroxetine-mediated GRK2 inhibition is a disease-modifying treatment for osteoarthritis. Sci Transl Med 2021; 13:13/580/eaau8491. [PMID: 33568523 DOI: 10.1126/scitranslmed.aau8491] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 10/07/2020] [Accepted: 01/19/2021] [Indexed: 01/15/2023]
Abstract
Osteoarthritis (OA) is a debilitating joint disease characterized by progressive cartilage degeneration, with no available disease-modifying therapy. OA is driven by pathological chondrocyte hypertrophy (CH), the cellular regulators of which are unknown. We have recently reported the therapeutic efficacy of G protein-coupled receptor kinase 2 (GRK2) inhibition in other diseases by recovering protective G protein-coupled receptor (GPCR) signaling. However, the role of GPCR-GRK2 pathway in OA is unknown. Thus, in a surgical OA mouse model, we performed genetic GRK2 deletion in chondrocytes or pharmacological inhibition with the repurposed U.S. Food and Drug Administration (FDA)-approved antidepressant paroxetine. Both GRK2 deletion and inhibition prevented CH, abated OA progression, and promoted cartilage regeneration. Supporting experiments with cultured human OA cartilage confirmed the ability of paroxetine to mitigate CH and cartilage degradation. Our findings present elevated GRK2 signaling in chondrocytes as a driver of CH in OA and identify paroxetine as a disease-modifying drug for OA treatment.
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Affiliation(s)
- Elijah L Carlson
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Vengadeshprabhu Karuppagounder
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - William J Pinamont
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Natalie K Yoshioka
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Adeel Ahmad
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA
| | | | | | - Michael J Zuscik
- Colorado Program for Skeletal Research, Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Reyad A Elbarbary
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA.,Department of Biochemistry and Molecular Biology, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
| | - Fadia Kamal
- Center for Orthopedic Research and Translational Sciences, Department of Orthopedics and Rehabilitation, Penn State College of Medicine, Hershey, PA 17033, USA. .,Department of Pharmacology, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
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6
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Fu Q, Wang Q, Xiang YK. Insulin and β Adrenergic Receptor Signaling: Crosstalk in Heart. Trends Endocrinol Metab 2017; 28:416-427. [PMID: 28256297 PMCID: PMC5535765 DOI: 10.1016/j.tem.2017.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 01/29/2017] [Accepted: 02/01/2017] [Indexed: 02/03/2023]
Abstract
Recent advances show that insulin may affect β adrenergic receptor (βAR) signaling in the heart to modulate cardiac function in clinically relevant states, such as diabetes mellitus (DM) and heart failure (HF). Conversely, activation of βAR regulates cardiac glucose uptake and promotes insulin resistance (IR) in HF. Here, we discuss the recent characterization of the interaction between the cardiac insulin receptor (InsR) and βAR in the myocardium, in which insulin stimulation crosstalks with cardiac βAR via InsR substrate (IRS)-dependent and G-protein receptor kinase 2 (GRK2)-mediated phosphorylation of β2AR. The insulin-induced phosphorylation promotes β2AR coupling to Gi and expression of phosphodiesterase 4D, which both inhibit cardiac adrenergic signaling and compromise cardiac contractile function. These recent developments could support new approaches for the effective prevention or treatment of obesity- or DM-related HF.
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Affiliation(s)
- Qin Fu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Huazhong University of Science and Technology, Wuhan, China.
| | - Qingtong Wang
- Institute of Clinical Pharmacology, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Anhui Medical University, Hefei, China.
| | - Yang K Xiang
- Department of Pharmacology, University of California, Davis, CA, USA; VA Northern California Health Care System, Mather, CA, USA.
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7
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Targeting GPCR-Gβγ-GRK2 signaling as a novel strategy for treating cardiorenal pathologies. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1883-1892. [PMID: 28130200 DOI: 10.1016/j.bbadis.2017.01.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 01/13/2017] [Accepted: 01/18/2017] [Indexed: 02/06/2023]
Abstract
The pathologic crosstalk between the heart and kidney is known as cardiorenal syndrome (CRS). While the specific mechanisms underlying this crosstalk remain poorly understood, CRS is associated with exacerbated dysfunction of either or both organs and reduced survival. Maladaptive fibrotic remodeling is a key component of both heart and kidney failure pathogenesis and progression. G-protein coupled receptor (GPCR) signaling is a crucial regulator of cardiovascular and renal function. Chronic/pathologic GPCR signaling elicits the interaction of the G-protein Gβγ subunit with GPCR kinase 2 (GRK2), targeting the receptor for internalization, scaffolding to pathologic signals, and receptor degradation. Targeting this pathologic Gβγ-GRK2 interaction has been suggested as a possible strategy for the treatment of HF. In the current review, we discuss recent updates in understanding the role of GPCR-Gβγ-GRK2 signaling as a crucial mediator of maladaptive organ remodeling detected in HF and kidney dysfunction, with specific attention to small molecule-mediated inhibition of pathologic Gβγ-GRK2 interactions. Further, we explore the potential of GPCR-Gβγ-GRK2 signaling as a possible therapeutic target for cardiorenal pathologies.
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8
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Jovancevic N, Dendorfer A, Matzkies M, Kovarova M, Heckmann JC, Osterloh M, Boehm M, Weber L, Nguemo F, Semmler J, Hescheler J, Milting H, Schleicher E, Gelis L, Hatt H. Medium-chain fatty acids modulate myocardial function via a cardiac odorant receptor. Basic Res Cardiol 2017; 112:13. [PMID: 28116519 PMCID: PMC5258789 DOI: 10.1007/s00395-017-0600-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 01/03/2017] [Indexed: 12/17/2022]
Abstract
Several studies have demonstrated the expression of odorant receptors (OR) in various human tissues and their involvement in different physiological and pathophysiological processes. However, the functional role of ORs in the human heart is still unclear. Here, we firstly report the functional characterization of an OR in the human heart. Initial next-generation sequencing analysis revealed the OR expression pattern in the adult and fetal human heart and identified the fatty acid-sensing OR51E1 as the most highly expressed OR in both cardiac development stages. An extensive characterization of the OR51E1 ligand profile by luciferase reporter gene activation assay identified 2-ethylhexanoic acid as a receptor antagonist and various structurally related fatty acids as novel OR51E1 ligands, some of which were detected at receptor-activating concentrations in plasma and epicardial adipose tissue. Functional investigation of the endogenous receptor was carried out by Ca2+ imaging of human stem cell-derived cardiomyocytes. Application of OR51E1 ligands induced negative chronotropic effects that depended on activation of the OR. OR51E1 activation also provoked a negative inotropic action in cardiac trabeculae and slice preparations of human explanted ventricles. These findings indicate that OR51E1 may play a role as metabolic regulator of cardiac function.
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Affiliation(s)
- Nikolina Jovancevic
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany.
| | - A Dendorfer
- Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians-University, 80336, Munich, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
| | - M Matzkies
- Institute for Neurophysiology, University of Cologne, 50931, Cologne, Germany
| | - M Kovarova
- Division of Pathobiochemistry and Clinical Chemistry, University of Tuebingen, 72076, Tuebingen, Germany
| | - J C Heckmann
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - M Osterloh
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - M Boehm
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - L Weber
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - F Nguemo
- Institute for Neurophysiology, University of Cologne, 50931, Cologne, Germany
| | - J Semmler
- Institute for Neurophysiology, University of Cologne, 50931, Cologne, Germany
| | - J Hescheler
- Institute for Neurophysiology, University of Cologne, 50931, Cologne, Germany
| | - H Milting
- Erich and Hanna Klessmann Institute, Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, Ruhr-University Bochum, 32545, Bad Oeynhausen, Germany
| | - E Schleicher
- Division of Pathobiochemistry and Clinical Chemistry, University of Tuebingen, 72076, Tuebingen, Germany
| | - L Gelis
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
| | - H Hatt
- Department of Cell Physiology, Ruhr-University Bochum, 44801, Bochum, Germany
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9
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Abstract
Myocardial fibrosis is a significant global health problem associated with nearly all forms of heart disease. Cardiac fibroblasts comprise an essential cell type in the heart that is responsible for the homeostasis of the extracellular matrix; however, upon injury, these cells transform to a myofibroblast phenotype and contribute to cardiac fibrosis. This remodeling involves pathological changes that include chamber dilation, cardiomyocyte hypertrophy and apoptosis, and ultimately leads to the progression to heart failure. Despite the critical importance of fibrosis in cardiovascular disease, our limited understanding of the cardiac fibroblast impedes the development of potential therapies that effectively target this cell type and its pathological contribution to disease progression. This review summarizes current knowledge regarding the origins and roles of fibroblasts, mediators and signaling pathways known to influence fibroblast function after myocardial injury, as well as novel therapeutic strategies under investigation to attenuate cardiac fibrosis.
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Affiliation(s)
- Joshua G Travers
- From the Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, OH
| | - Fadia A Kamal
- From the Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, OH
| | - Jeffrey Robbins
- From the Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, OH
| | - Katherine E Yutzey
- From the Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, OH
| | - Burns C Blaxall
- From the Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children's Hospital Medical Center, OH.
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10
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Bernardo BC, Blaxall BC. From Bench to Bedside: New Approaches to Therapeutic Discovery for Heart Failure. Heart Lung Circ 2016; 25:425-34. [PMID: 26993094 DOI: 10.1016/j.hlc.2016.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 01/06/2016] [Indexed: 01/10/2023]
Abstract
Heart failure is a significant global health problem, which is becoming worse as the population ages, and remains one of the biggest burdens on our economy. Despite significant advances in cardiovascular medicine, management and surgery, mortality rates remain high, with almost half of patients with heart failure dying within five years of diagnosis. As a multifactorial clinical syndrome, heart failure still represents an epidemic threat, highlighting the need for deeper insights into disease mechanisms and the development of innovative therapeutic strategies for both treatment and prevention. In this review, we discuss conventional heart failure therapies and highlight new pharmacological agents targeting pathophysiological features of the failing heart, for example, non-coding RNAs, angiotensin receptor-neprilysin inhibitors, cardiac myosin activators, BGP-15 and molecules targeting GRK2 including M119, gallein and paroxetine. Finally, we address the disparity between phase II and phase III clinical trials that prevent the translation of emerging HF therapies into new and approved therapies.
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Affiliation(s)
- Bianca C Bernardo
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Burns C Blaxall
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
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11
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Subramanian H, Gupta K, Parameswaran N, Ali H. Regulation of Fc∈RI signaling in mast cells by G protein-coupled receptor kinase 2 and its RH domain. J Biol Chem 2015; 289:20917-27. [PMID: 24904059 DOI: 10.1074/jbc.m113.523969] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Agonist-induced phosphorylation of G protein-coupled receptors (GPCRs) by GPCRkinases (GRKs) promotes their desensitization and internalization. Here, we sought to determine the role of GRK2 on Fc∈RI signaling and mediator release in mast cells. The strategies utilized included lentiviral shRNA-mediated GRK2 knockdown, GRK2 gene deletion (GRK2(flox/flox)/cre recombinase) and overexpression of GRK2 and its regulator of G protein signaling homology (RH) domain (GRK2-RH). We found that silencing GRK2 expression caused ~50% decrease in antigen-induced Ca(2+) mobilization and degranulation but resulted in ablation of cytokine (IL-6 and IL-13) generation. The effect of GRK2 on cytokine generation does not require its catalytic activity but is mediated via the phosphorylation of p38 and Akt. Overexpression of GRK2 or its RH domain (GRK2-RH) enhanced antigen-induced mast cell degranulation and cytokine generation without affecting the expression levels of any of the Fc∈RI subunits (α, β, and γ). GRK2 or GRK2-RH had no effect on antigen-induced phosphorylation of Fc∈RIγ or Src but enhanced tyrosine phosphorylation of Syk. These data demonstrate that GRK2 modulates Fc∈RI signaling in mast cells via at least two mechanisms.One involves GRK2-RH and modulates tyrosine phosphorylation of Syk, and the other is mediated via the phosphorylation of p38 and Akt.
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12
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Modulation of the cAMP response by Gαi and Gβγ: a computational study of G protein signaling in immune cells. Bull Math Biol 2014; 76:1352-75. [PMID: 24809944 DOI: 10.1007/s11538-014-9964-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 04/14/2014] [Indexed: 12/15/2022]
Abstract
Cyclic AMP is important for the resolution of inflammation, as it promotes anti-inflammatory signaling in several immune cell lines. In this paper, we present an immune cell specific model of the cAMP signaling cascade, paying close attention to the specific isoforms of adenylyl cyclase (AC) and phosphodiesterase that control cAMP production and degradation, respectively, in these cells. The model describes the role that G protein subunits, including Gαs, Gαi, and Gβγ, have in regulating cAMP production. Previously, Gαi activation has been shown to increase the level of cAMP in certain immune cell types. This increase in cAMP is thought to be mediated by βγ subunits which are released upon Gα activation and can directly stimulate specific isoforms of AC. We conduct numerical experiments in order to explore the mechanisms through which Gαi activation can increase cAMP production. An important conclusion of our analysis is that the relative abundance of different G protein subunits is an essential determinant of the cAMP profile in immune cells. In particular, our model predicts that limited availability of βγ subunits may both (i) enable immune cells to link inflammatory Gαi signaling to anti-inflammatory cAMP production thereby creating a balanced immune response to stimulation with low concentrations of PGE2, and (ii) prohibit robust anti-inflammatory cAMP signaling in response to stimulation with high concentrations of PGE2.
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13
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Kamal FA, Mickelsen DM, Wegman KM, Travers JG, Moalem J, Hammes SR, Smrcka AV, Blaxall BC. Simultaneous adrenal and cardiac g-protein-coupled receptor-gβγ inhibition halts heart failure progression. J Am Coll Cardiol 2014; 63:2549-2557. [PMID: 24703913 DOI: 10.1016/j.jacc.2014.02.587] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/10/2014] [Accepted: 02/25/2014] [Indexed: 12/29/2022]
Abstract
OBJECTIVES The authors propose simultaneous inhibition of Gβγ signaling in the heart and the adrenal gland as a novel therapeutic approach for heart failure (HF). BACKGROUND Elevated sympathetic nervous system activity is a salient characteristic of HF progression. It causes pathologic desensitization of β-adrenergic receptors (β-AR), facilitated predominantly through Gβγ-mediated signaling. The adrenal glands are key contributors to the chronically elevated plasma catecholamine levels observed in HF, where adrenal α2-AR feedback inhibitory function is impaired also through Gβγ-mediated signaling. METHODS We investigated the efficacy of a small molecule Gβγ inhibitor, gallein, in a clinically relevant, pressure-overload model of HF. RESULTS Daily gallein treatment (10 mg/kg/day), initiated 4 weeks after transverse aortic constriction, improved survival and cardiac function and attenuated cardiac remodeling. Mechanistically, gallein restored β-AR membrane density in cardiomyocytes, attenuated Gβγ-mediated G-protein-coupled receptor kinase 2-phosphoinositide 3-kinase γ membrane recruitment, and reduced Akt (protein kinase B) and glycogen synthase kinase 3β phosphorylation. Gallein also reduced circulating plasma catecholamine levels and catecholamine production in isolated mouse adrenal glands by restoring adrenal α2-AR feedback inhibition. In human adrenal endocrine tumors (pheochromocytoma), gallein attenuated catecholamine secretion, as well as G-protein-coupled receptor kinase 2 expression and membrane translocation. CONCLUSIONS These data suggest small molecule Gβγ inhibition as a systemic pharmacologic therapy for HF by simultaneously normalizing pathologic adrenergic/Gβγ signaling in both the heart and the adrenal gland. Our data also suggest important endocrine/cardiovascular interactions and a possible role for small molecule Gβγ inhibition in treating endocrine tumors such as pheochromocytoma, in addition to HF.
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Affiliation(s)
- Fadia A Kamal
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Deanne M Mickelsen
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester Medical Center, Rochester, New York
| | - Katherine M Wegman
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Joshua G Travers
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Jacob Moalem
- Department of Surgery, University of Rochester Medical Center, Rochester, New York; Department of Medicine, University of Rochester Medical Center, Rochester, New York
| | - Stephen R Hammes
- Department of Medicine, University of Rochester Medical Center, Rochester, New York
| | - Alan V Smrcka
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York
| | - Burns C Blaxall
- The Heart Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
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14
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Ferguson SSG, Feldman RD. β-adrenoceptors as molecular targets in the treatment of hypertension. Can J Cardiol 2014; 30:S3-8. [PMID: 24685403 DOI: 10.1016/j.cjca.2014.01.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 01/31/2014] [Accepted: 01/31/2014] [Indexed: 01/14/2023] Open
Abstract
Regulation of sympathoadrenal activity has been a long-time target in the management of hypertension. Regulation of β-adrenoceptor (βAR) function has been the most therapeutically important of these targets. The development of effective antihypertensive treatments based on βAR antagonism paralleled the elucidation of the molecular basis of β-adrenergic effects by the family of βARs, which are members of the G-protein-coupled receptor (GPCR) superfamily. βARs serve as the extracellular face of the transmembrane signalling pathway that results in the consequent activation of heterotrimeric G-proteins and the activation of several other newly appreciated signalling molecules that include β-arrestins and GPCR kinases (GRKs). The aggregate effect of the activation of these signalling pathways mediates the response to βAR activation. Paradoxically, the hypertensive state is characterized by impaired βAR responsiveness. This defect is common to many other receptor systems linked to the stimulator G protein (Gs) and adenylyl cyclase activation. This impairment is principally mediated by receptor-G-protein uncoupling, which has been linked to increased expression and activity of GRK2.
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Affiliation(s)
- Stephen S G Ferguson
- J. Allyn Taylor Centre for Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Ross D Feldman
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada; Vascular Biology Research Group, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; Department of Medicine, University of Western Ontario, London, Ontario, Canada.
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15
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Lorenz K, Stathopoulou K, Schmid E, Eder P, Cuello F. Heart failure-specific changes in protein kinase signalling. Pflugers Arch 2014; 466:1151-62. [DOI: 10.1007/s00424-014-1462-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 01/19/2014] [Accepted: 01/22/2014] [Indexed: 01/14/2023]
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16
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Abstract
Despite declines in heart failure morbidity and mortality with current therapies, rehospitalization rates remain distressingly high, substantially affecting individuals, society, and the economy. As a result, the need for new therapeutic advances and novel medical devices is urgent. Disease-related left ventricular remodeling is a complex process involving cardiac myocyte growth and death, vascular rarefaction, fibrosis, inflammation, and electrophysiological remodeling. Because these events are highly interrelated, targeting a single molecule or process may not be sufficient. Here, we review molecular and cellular mechanisms governing pathological ventricular remodeling.
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17
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Smrcka AV. Molecular targeting of Gα and Gβγ subunits: a potential approach for cancer therapeutics. Trends Pharmacol Sci 2013; 34:290-8. [PMID: 23557963 DOI: 10.1016/j.tips.2013.02.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/21/2013] [Accepted: 02/26/2013] [Indexed: 11/26/2022]
Abstract
G-Protein-coupled receptors (GPCRs) signal through G protein α and βγ subunit families to regulate a wide range of physiological and pathophysiological processes. As such, GPCRs are major targets for therapeutic drugs. Downstream targets of GPCRs have also gained interest as a therapeutic approach to complex pathologies involving multiple GPCRs. One such approach involves targeting of the G proteins themselves. Several small molecule Gα and Gβγ modulators have been developed and been tested in various animal models of disease. Here we will discuss the requirements for targeting Gα and Gβγ subunits, the mechanisms of action of currently identified inhibitors, and focus on the potential utility of Gα and Gβγ inhibitors in the treatment of various cancers.
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Affiliation(s)
- Alan V Smrcka
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
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18
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San Martin L, Cerda F, Jimenez V, Fuentealba J, Muñoz B, Aguayo LG, Guzman L. Inhibition of the ethanol-induced potentiation of α1 glycine receptor by a small peptide that interferes with Gβγ binding. J Biol Chem 2012; 287:40713-21. [PMID: 23035114 DOI: 10.1074/jbc.m112.393603] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Gβγ interaction with GlyR is an important determinant in ethanol potentiation of this channel. RESULTS A small peptide, RQH(C7), can inhibit ethanol potentiation of GlyR currents. CONCLUSION Results with RQH(C7) indicate that ethanol mediated potentiation of GlyR is in part by Gβγ activation. SIGNIFICANCE Molecular interaction between Gβγ and GlyR could be used as a target for pharmacological modification of ethanol effects. Previous studies indicate that ethanol can modulate glycine receptors (GlyR), in part, through Gβγ interaction with basic residues in the intracellular loop. In this study, we show that a seven-amino acid peptide (RQH(C7)), which has the primary structure of a motif in the large intracellular loop of GlyR (GlyR-IL), was able to inhibit the ethanol-elicited potentiation of this channel from 47 ± 2 to 16 ± 4%, without interfering with the effect of Gβγ on GIRK (G protein activated inwardly rectifying potassium channel) activation. RQH(C7) displayed a concentration-dependent effect on ethanol action in evoked and synaptic currents. A fragment of GlyR-IL without the basic amino acids did not interact with Gβγ or inhibit ethanol potentiation of GlyR. In silico analysis using docking and molecular dynamics allowed to identify a region of ~350Å(2) involving aspartic acids 186, 228, and 246 in Gβγ where we propose that RQH(C7) binds and exerts its blocking action on the effect of ethanol in GlyR.
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Affiliation(s)
- Loreto San Martin
- Department of Physiology, Faculty of Biological Sciences, University of Concepcion, 403901 Concepcion, Chile
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19
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Belmonte SL, Blaxall BC. Conducting the G-protein Coupled Receptor (GPCR) Signaling Symphony in Cardiovascular Diseases: New Therapeutic Approaches. ACTA ACUST UNITED AC 2012; 9:e85-e90. [PMID: 23162605 DOI: 10.1016/j.ddmod.2012.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
G protein-coupled receptors (GPCRs) are a virtually ubiquitous class of membrane-bound receptors, which functionally couple hormone or neurotransmitter signals to physiological responses. Dysregulation of GPCR signaling contributes to the pathophysiology of a host of cardiovascular disorders. Pharmacological agents targeting GPCRs have been established as therapeutic options for decades. Nevertheless, the persistent burden of cardiovascular diseases necessitates improved treatments. To that end, exciting drug development efforts have begun to focus on novel compounds that discriminately activate particular GPCR signaling pathways.
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Affiliation(s)
- Stephen L Belmonte
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester Medical Center, Rochester, NY, USA
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20
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Mohan ML, Vasudevan NT, Gupta MK, Martelli EE, Naga Prasad SV. G-protein coupled receptor resensitization-appreciating the balancing act of receptor function. Curr Mol Pharmacol 2012:CMP-EPUB-20120530-2. [PMID: 22697395 PMCID: PMC4607669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 11/22/2011] [Accepted: 11/28/2011] [Indexed: 06/01/2023]
Abstract
G-protein coupled receptors (GPCRs) are seven transmembrane receptors that are pivotal regulators of cellular responses including vision, cardiac contractility, olfaction, and platelet activation. GPCRs have been a major target for drug discovery due to their role in regulating a broad range of physiological and pathological responses. GPCRs mediate these responses through a cyclical process of receptor activation (initiation of downstream signals), desensitization (inactivation that results in diminution of downstream signals), and resensitization (receptor reactivation for next wave of activation). Although these steps may be of equal importance in regulating receptor function, significant advances have been made in understanding activation and desensitization with limited effort towards resensitization. Inadequate importance has been given to resensitization due to the understanding that resensitization is a homeostasis maintaining process and is not acutely regulated. Evidence indicates that resensitization is a critical step in regulating GPCR function and may contribute towards receptor signaling and cellular responses. In light of these observations, it is imperative to discuss resensitization as a dynamic and mechanistic regulator of GPCR function. In this review we discuss components regulating GPCR function like activation, desensitization, and internalization with special emphasis on resensitization. Although we have used β-adrenergic receptor as a proto-type GPCR to discuss mechanisms regulating receptor function, other GPCRs are also described to put forth a view point on the universality of such mechanisms.
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Affiliation(s)
- Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH, 44195.
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21
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Abstract
G protein-coupled receptors (GPCRs) represent the largest family of membrane receptors and are responsible for regulating a wide variety of physiological processes. This is accomplished via ligand binding to GPCRs, activating associated heterotrimeric G proteins and intracellular signaling pathways. G protein-coupled receptor kinases (GRKs), in concert with β-arrestins, classically desensitize receptor signal transduction, thus preventing hyperactivation of GPCR second-messenger cascades. As changes in GRK expression have featured prominently in many cardiovascular pathologies, including heart failure, myocardial infarction, hypertension, and cardiac hypertrophy, GRKs have been intensively studied as potential diagnostic or therapeutic targets. Herein, we review our evolving understanding of the role of GRKs in cardiovascular pathophysiology.
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Affiliation(s)
- Stephen L Belmonte
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
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22
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Abstract
Signal transduction through G-protein-coupled receptors (GPCRs) is central for the regulation of virtually all cellular functions and has been widely implicated in human disease. Regulators of G-protein signaling (RGS proteins) belong to a diverse protein family that was originally discovered for their ability to accelerate signal termination in response to GPCR stimulation, thereby reducing the amplitude and duration of GPCR effects. All RGS proteins share a common RGS domain that interacts with G protein α subunits and mediates their biological regulation of GPCR signaling. However, RGS proteins differ widely in size and the organization of their sequences flanking the RGS domain, which contain several additional functional domains that facilitate protein-protein (or protein-lipid) interactions. RGS proteins are subject to posttranslational modifications, and, in addition, their expression, activity, and subcellular localization can be dynamically regulated. Thus, there exists a wide array of mechanisms that facilitate their proper function as modulators and integrators of G-protein signaling. Several RGS proteins have been implicated in the cardiac remodeling response and heart rate regulation, and changes in RGS protein expression and/or function are believed to participate in the pathophysiology of cardiac hypertrophy, failure and arrhythmias as well as hypertension. This review is based on recent advances in our understanding of the expression pattern, regulation, and functional role of canonical RGS proteins, with a special focus on the healthy heart and the diseased heart. In addition, we discuss their potential and promise as therapeutic targets as well as strategies to modulate their expression and function.
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Affiliation(s)
- Peng Zhang
- Cardiovascular Research Center, Rhode Island Hospital and Alpert Medical School of Brown University, 1 Hoppin St, Providence, RI 02903, USA
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23
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Simpson PC. Where are the new drugs to treat heart failure? Introduction to the special issue on "key signaling molecules in hypertrophy and heart failure". J Mol Cell Cardiol 2011; 51:435-7. [PMID: 21851824 DOI: 10.1016/j.yjmcc.2011.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 08/10/2011] [Indexed: 12/30/2022]
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24
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Pharmacologic and genetic strategies to enhance cell therapy for cardiac regeneration. J Mol Cell Cardiol 2011; 51:619-25. [PMID: 21645519 DOI: 10.1016/j.yjmcc.2011.05.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/18/2011] [Accepted: 05/20/2011] [Indexed: 01/16/2023]
Abstract
Cell-based therapy is emerging as an exciting potential therapeutic approach for cardiac regeneration following myocardial infarction (MI). As heart failure (HF) prevalence increases over time, development of new interventions designed to aid cardiac recovery from injury are crucial and should be considered more broadly. In this regard, substantial efforts to enhance the efficacy and safety of cell therapy are continuously growing along several fronts, including modifications to improve the reprogramming efficiency of inducible pluripotent stem cells (iPS), genetic engineering of adult stem cells, and administration of growth factors or small molecules to activate regenerative pathways in the injured heart. These interventions are emerging as potential therapeutic alternatives and/or adjuncts based on their potential to promote stem cell homing, proliferation, differentiation, and/or survival. Given the promise of therapeutic interventions to enhance the regenerative capacity of multipotent stem cells as well as specifically guide endogenous or exogenous stem cells into a cardiac lineage, their application in cardiac regenerative medicine should be the focus of future clinical research. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."
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