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Rivas V, González-Muñoz T, Albitre Á, Lafarga V, Delgado-Arévalo C, Mayor F, Penela P. GRK2-mediated AKT activation controls cell cycle progression and G2 checkpoint in a p53-dependent manner. Cell Death Discov 2024; 10:385. [PMID: 39198399 PMCID: PMC11358448 DOI: 10.1038/s41420-024-02143-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 08/03/2024] [Accepted: 08/09/2024] [Indexed: 09/01/2024] Open
Abstract
Cell cycle checkpoints, activated by stressful events, halt the cell cycle progression, and prevent the transmission of damaged DNA. These checkpoints prompt cell repair but also trigger cell death if damage persists. Decision-making between these responses is multifactorial and context-dependent, with the tumor suppressor p53 playing a central role. In many tumor cells, p53 alterations lead to G1/S checkpoint loss and the weakening of the G2 checkpoint, rendering cell viability dependent on the strength of the latter through mechanisms not fully characterized. Cells with a strong pro-survival drive can evade cell death despite substantial DNA lesions. Deciphering the integration of survival pathways with p53-dependent and -independent mechanisms governing the G2/M transition is crucial for understanding G2 arrest functionality and predicting tumor cell response to chemotherapy. The serine/threonine kinase GRK2 emerges as a signaling node in cell cycle modulation. In cycling cells, but not in G2 checkpoint-arrested cells, GRK2 protein levels decline during G2/M transition through a process triggered by CDK2-dependent phosphorylation of GRK2 at the S670 residue and Mdm2 ubiquitination. We report now that this downmodulation in G2 prevents the unscheduled activation of the PI3K/AKT pathway, allowing cells to progress into mitosis. Conversely, higher GRK2 levels lead to tyrosine phosphorylation by the kinase c-Abl, promoting the direct association of GRK2 with the p85 regulatory subunit of PI3K and AKT activation in a GRK2 catalytic-independent manner. Hyperactivation of AKT is conditioned by p53's scaffolding function, triggering FOXO3a phosphorylation, impaired Cyclin B1 accumulation, and CDK1 activation, causing a G2/M transition delay. Upon G2 checkpoint activation, GRK2 potentiates early arrest independently of p53 through AKT activation. However, its ability to overcome the G2 checkpoint in viable conditions depends on p53. Our results suggest that integrating the GRK2/PI3K/AKT axis with non-canonical functions of p53 might confer a survival advantage to tumor cells.
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Affiliation(s)
- Verónica Rivas
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
| | - Teresa González-Muñoz
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
| | - Ángela Albitre
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
| | - Vanesa Lafarga
- Department of Molecular Oncology, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Cristina Delgado-Arévalo
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
| | - Federico Mayor
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), Madrid, Spain
| | - Petronila Penela
- Departamento de Biología Molecular, IUBM-UAM and Centro de Biología Molecular "Severo Ochoa" (UAM-CSIC), Madrid, Spain.
- Instituto de Investigación Sanitaria La Princesa, Madrid, Spain.
- CIBER de Enfermedades Cardiovasculares, ISCIII (CIBERCV), Madrid, Spain.
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Liu S, Anderson PJ, Rajagopal S, Lefkowitz RJ, Rockman HA. G Protein-Coupled Receptors: A Century of Research and Discovery. Circ Res 2024; 135:174-197. [PMID: 38900852 PMCID: PMC11192237 DOI: 10.1161/circresaha.124.323067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
GPCRs (G protein-coupled receptors), also known as 7 transmembrane domain receptors, are the largest receptor family in the human genome, with ≈800 members. GPCRs regulate nearly every aspect of human physiology and disease, thus serving as important drug targets in cardiovascular disease. Sharing a conserved structure comprised of 7 transmembrane α-helices, GPCRs couple to heterotrimeric G-proteins, GPCR kinases, and β-arrestins, promoting downstream signaling through second messengers and other intracellular signaling pathways. GPCR drug development has led to important cardiovascular therapies, such as antagonists of β-adrenergic and angiotensin II receptors for heart failure and hypertension, and agonists of the glucagon-like peptide-1 receptor for reducing adverse cardiovascular events and other emerging indications. There continues to be a major interest in GPCR drug development in cardiovascular and cardiometabolic disease, driven by advances in GPCR mechanistic studies and structure-based drug design. This review recounts the rich history of GPCR research, including the current state of clinically used GPCR drugs, and highlights newly discovered aspects of GPCR biology and promising directions for future investigation. As additional mechanisms for regulating GPCR signaling are uncovered, new strategies for targeting these ubiquitous receptors hold tremendous promise for the field of cardiovascular medicine.
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Affiliation(s)
- Samuel Liu
- Department of Medicine, Duke University Medical
Center
| | - Preston J. Anderson
- Cell and Molecular Biology (CMB), Duke University, Durham,
NC, 27710, USA
- Duke Medical Scientist Training Program, Duke University,
Durham, NC, 27710, USA
| | - Sudarshan Rajagopal
- Department of Medicine, Duke University Medical
Center
- Cell and Molecular Biology (CMB), Duke University, Durham,
NC, 27710, USA
- Deparment of Biochemistry Duke University, Durham, NC,
27710, USA
| | - Robert J. Lefkowitz
- Department of Medicine, Duke University Medical
Center
- Deparment of Biochemistry Duke University, Durham, NC,
27710, USA
- Howard Hughes Medical Institute, Duke University Medical
Center, Durham, North Carolina 27710, USA
| | - Howard A. Rockman
- Department of Medicine, Duke University Medical
Center
- Cell and Molecular Biology (CMB), Duke University, Durham,
NC, 27710, USA
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Xu B, Bahriz S, Salemme VR, Wang Y, Zhu C, Zhao M, Xiang YK. Differential Downregulation of β 1-Adrenergic Receptor Signaling in the Heart. J Am Heart Assoc 2024; 13:e033733. [PMID: 38860414 PMCID: PMC11255761 DOI: 10.1161/jaha.123.033733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/15/2024] [Indexed: 06/12/2024]
Abstract
BACKGROUND Chronic sympathetic stimulation drives desensitization and downregulation of β1 adrenergic receptor (β1AR) in heart failure. We aim to explore the differential downregulation subcellular pools of β1AR signaling in the heart. METHODS AND RESULTS We applied chronic infusion of isoproterenol to induced cardiomyopathy in male C57BL/6J mice. We applied confocal and proximity ligation assay to examine β1AR association with L-type calcium channel, ryanodine receptor 2, and SERCA2a ((Sarco)endoplasmic reticulum calcium ATPase 2a) and Förster resonance energy transfer-based biosensors to probe subcellular β1AR-PKA (protein kinase A) signaling in ventricular myocytes. Chronic infusion of isoproterenol led to reduced β1AR protein levels, receptor association with L-type calcium channel and ryanodine receptor 2 measured by proximity ligation (puncta/cell, 29.65 saline versus 14.17 isoproterenol, P<0.05), and receptor-induced PKA signaling at the plasma membrane (Förster resonance energy transfer, 28.9% saline versus 1.9% isoproterenol, P<0.05) and ryanodine receptor 2 complex (Förster resonance energy transfer, 30.2% saline versus 10.6% isoproterenol, P<0.05). However, the β1AR association with SERCA2a was enhanced (puncta/cell, 51.4 saline versus 87.5 isoproterenol, P<0.05), and the receptor signal was minimally affected. The isoproterenol-infused hearts displayed decreased PDE4D (phosphodiesterase 4D) and PDE3A and increased PDE2A, PDE4A, and PDE4B protein levels. We observed a reduced role of PDE4 and enhanced roles of PDE2 and PDE3 on the β1AR-PKA activity at the ryanodine receptor 2 complexes and myocyte shortening. Despite the enhanced β1AR association with SERCA2a, the endogenous norepinephrine-induced signaling was reduced at the SERCA2a complexes. Inhibiting monoamine oxidase A rescued the norepinephrine-induced PKA signaling at the SERCA2a and myocyte shortening. CONCLUSIONS This study reveals distinct mechanisms for the downregulation of subcellular β1AR signaling in the heart under chronic adrenergic stimulation.
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Affiliation(s)
- Bing Xu
- VA Northern California Health Care SystemMatherCAUSA
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
| | - Sherif Bahriz
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
- Department of Clinical Pathology, Faculty of MedicineMansoura UniversityMansouraEgypt
| | | | - Ying Wang
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
- Department of Pharmacology, School of MedicineSouthern University of Science and TechnologyShenzhenChina
| | - Chaoqun Zhu
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
| | - Meimi Zhao
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
- Department of Pharmaceutical ToxicologyChina Medical UniversityShenyangChina
| | - Yang K. Xiang
- VA Northern California Health Care SystemMatherCAUSA
- Department of PharmacologyUniversity of California at DavisDavisCAUSA
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Ham S, Mukaida S, Sato M, Keov P, Bengtsson T, Furness S, Holliday ND, Evans BA, Summers RJ, Hutchinson DS. Role of G protein-coupled receptor kinases (GRKs) in β 2 -adrenoceptor-mediated glucose uptake. Pharmacol Res Perspect 2024; 12:e1176. [PMID: 38332691 PMCID: PMC10853676 DOI: 10.1002/prp2.1176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/17/2023] [Accepted: 01/22/2024] [Indexed: 02/10/2024] Open
Abstract
Truncation of the C-terminal tail of the β2 -AR, transfection of βARKct or over-expression of a kinase-dead GRK mutant reduces isoprenaline-stimulated glucose uptake, indicating that GRK is important for this response. We explored whether phosphorylation of the β2 -AR by GRK2 has a role in glucose uptake or if this response is related to the role of GRK2 as a scaffolding protein. CHO-GLUT4myc cells expressing wild-type and mutant β2 -ARs were generated and receptor affinity for [3 H]-CGP12177A and density of binding sites determined together with the affinity of isoprenaline and BRL37344. Following receptor activation by β2 -AR agonists, cAMP accumulation, GLUT4 translocation, [3 H]-2-deoxyglucose uptake, and β2 -AR internalization were measured. Bioluminescence resonance energy transfer was used to investigate interactions between β2 -AR and β-arrestin2 or between β2 -AR and GRK2. Glucose uptake after siRNA knockdown or GRK inhibitors was measured in response to β2 -AR agonists. BRL37344 was a poor partial agonist for cAMP generation but displayed similar potency and efficacy to isoprenaline for glucose uptake and GLUT4 translocation. These responses to β2 -AR agonists occurred in CHO-GLUT4myc cells expressing β2 -ARs lacking GRK or GRK/PKA phosphorylation sites as well as in cells expressing the wild-type β2 -AR. However, β2 -ARs lacking phosphorylation sites failed to recruit β-arrestin2 and did not internalize. GRK2 knock-down or GRK2 inhibitors decreased isoprenaline-stimulated glucose uptake in rat L6 skeletal muscle cells. Thus, GRK phosphorylation of the β2 -AR is not associated with isoprenaline- or BRL37344-stimulated glucose uptake. However, GRKs acting as scaffold proteins are important for glucose uptake as GRK2 knock-down or GRK2 inhibition reduces isoprenaline-stimulated glucose uptake.
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Affiliation(s)
- Seungmin Ham
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Saori Mukaida
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Masaaki Sato
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Peter Keov
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Tore Bengtsson
- Atrogi ABStockholmSweden
- Department of Molecular BiosciencesThe Wenner‐Gren Institute, Stockholm UniversityStockholmSweden
| | - Sebastian Furness
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Nicholas D. Holliday
- School of Life Sciences, The Medical School, Queen's Medical CentreUniversity of NottinghamNottinghamUK
- Excellerate Bioscience, BiocityNottinghamUK
| | - Bronwyn A. Evans
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Roger J. Summers
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
| | - Dana S. Hutchinson
- Drug Discovery BiologyMonash Institute of Pharmaceutical Sciences, Monash UniversityParkvilleVictoriaAustralia
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5
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Sun Y, Stenson K, Mohan ML, Gupta MK, Wanner N, Asosingh K, Erzurum S, Naga Prasad SV. Hypoxia Sensing of β-Adrenergic Receptor Is Regulated by Endosomal PI3Kγ. Circ Res 2023; 132:690-703. [PMID: 36779349 PMCID: PMC10023460 DOI: 10.1161/circresaha.122.321735] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/31/2023] [Indexed: 02/14/2023]
Abstract
BACKGROUND Impaired beta-adrenergic receptor (β1 and β2AR) function following hypoxia underlies ischemic heart failure/stroke. Activation of PI3Kγ (phosphoinositide 3-kinase γ) by beta-adrenergic receptor leads to feedback regulation of the receptor by hindering beta-adrenergic receptor dephosphorylation through inhibition of PP2A (protein phosphatase 2A). However, little is known about PI3Kγ feedback mechanism in regulating hypoxia-mediated β1 and β2AR dysfunction and cardiac remodeling. METHODS Human embryonic kidney 293 cells or mouse adult cardiomyocytes and C57BL/6 (WT) or PI3Kγ knockout (KO) mice were subjected to hypoxia. Cardiac plasma membranes and endosomes were isolated and evaluated for β1 and β2AR density and function, PI3Kγ activity and β1 and β2AR-associated PP2A activity. Metabolic labeling was performed to assess β1 and β2AR phosphorylation and epinephrine/norepinephrine levels measured post-hypoxia. RESULTS Hypoxia increased β1 and β2AR phosphorylation, reduced cAMP, and led to endosomal accumulation of phosphorylated β2ARs in human embryonic kidney 293 cells and WT cardiomyocytes. Acute hypoxia in WT mice resulted in cardiac remodeling and loss of adenylyl cyclase activity associated with increased β1 and β2AR phosphorylation. This was agonist-independent as plasma and cardiac epinephrine and norepinephrine levels were unaltered. Unexpectedly, PI3Kγ activity was selectively increased in the endosomes of human embryonic kidney 293 cells and WT hearts post-hypoxia. Endosomal β1- and β2AR-associated PP2A activity was inhibited upon hypoxia in human embryonic kidney 293 cells and WT hearts showing regulation of beta-adrenergic receptors by PI3Kγ. This was accompanied with phosphorylation of endogenous inhibitor of protein phosphatase 2A whose phosphorylation by PI3Kγ inhibits PP2A. Increased β1 and β2AR-associated PP2A activity, decreased beta-adrenergic receptor phosphorylation, and normalized cardiac function was observed in PI3Kγ KO mice despite hypoxia. Compared to WT, PI3Kγ KO mice had preserved cardiac response to challenge with β1AR-selective agonist dobutamine post-hypoxia. CONCLUSIONS Agonist-independent activation of PI3Kγ underlies hypoxia sensing as its ablation leads to reduction in β1- and β2AR phosphorylation and amelioration of cardiac dysfunction.
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Affiliation(s)
- Yu Sun
- Departments of Cardiovascular and Metabolic Sciences (Y.S., K.S., M.L.M., M.K.G., S.V., N.P.), Lerner Research Institute, Cleveland Clinic, OH
| | - Kate Stenson
- Departments of Cardiovascular and Metabolic Sciences (Y.S., K.S., M.L.M., M.K.G., S.V., N.P.), Lerner Research Institute, Cleveland Clinic, OH
| | - Maradumane L Mohan
- Departments of Cardiovascular and Metabolic Sciences (Y.S., K.S., M.L.M., M.K.G., S.V., N.P.), Lerner Research Institute, Cleveland Clinic, OH
| | - Manveen K Gupta
- Departments of Cardiovascular and Metabolic Sciences (Y.S., K.S., M.L.M., M.K.G., S.V., N.P.), Lerner Research Institute, Cleveland Clinic, OH
| | - Nick Wanner
- Inflammation and Immunity (N.W., K.A., S.E.), Lerner Research Institute, Cleveland Clinic, OH
| | - Kewal Asosingh
- Inflammation and Immunity (N.W., K.A., S.E.), Lerner Research Institute, Cleveland Clinic, OH
| | - Serpil Erzurum
- Inflammation and Immunity (N.W., K.A., S.E.), Lerner Research Institute, Cleveland Clinic, OH
| | - Sathyamangla V Naga Prasad
- Departments of Cardiovascular and Metabolic Sciences (Y.S., K.S., M.L.M., M.K.G., S.V., N.P.), Lerner Research Institute, Cleveland Clinic, OH
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6
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Tarasov KV, Chakir K, Riordon DR, Lyashkov AE, Ahmet I, Perino MG, Silvester AJ, Zhang J, Wang M, Lukyanenko YO, Qu JH, Barrera MCR, Juhaszova M, Tarasova YS, Ziman B, Telljohann R, Kumar V, Ranek M, Lammons J, Bychkov R, de Cabo R, Jun S, Keceli G, Gupta A, Yang D, Aon MA, Adamo L, Morrell CH, Otu W, Carroll C, Chambers S, Paolocci N, Huynh T, Pacak K, Weiss R, Field L, Sollott SJ, Lakatta EG. A remarkable adaptive paradigm of heart performance and protection emerges in response to marked cardiac-specific overexpression of ADCY8. eLife 2022; 11:e80949. [PMID: 36515265 PMCID: PMC9822292 DOI: 10.7554/elife.80949] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Adult (3 month) mice with cardiac-specific overexpression of adenylyl cyclase (AC) type VIII (TGAC8) adapt to an increased cAMP-induced cardiac workload (~30% increases in heart rate, ejection fraction and cardiac output) for up to a year without signs of heart failure or excessive mortality. Here, we show classical cardiac hypertrophy markers were absent in TGAC8, and that total left ventricular (LV) mass was not increased: a reduced LV cavity volume in TGAC8 was encased by thicker LV walls harboring an increased number of small cardiac myocytes, and a network of small interstitial proliferative non-cardiac myocytes compared to wild type (WT) littermates; Protein synthesis, proteosome activity, and autophagy were enhanced in TGAC8 vs WT, and Nrf-2, Hsp90α, and ACC2 protein levels were increased. Despite increased energy demands in vivo LV ATP and phosphocreatine levels in TGAC8 did not differ from WT. Unbiased omics analyses identified more than 2,000 transcripts and proteins, comprising a broad array of biological processes across multiple cellular compartments, which differed by genotype; compared to WT, in TGAC8 there was a shift from fatty acid oxidation to aerobic glycolysis in the context of increased utilization of the pentose phosphate shunt and nucleotide synthesis. Thus, marked overexpression of AC8 engages complex, coordinate adaptation "circuity" that has evolved in mammalian cells to defend against stress that threatens health or life (elements of which have already been shown to be central to cardiac ischemic pre-conditioning and exercise endurance cardiac conditioning) that may be of biological significance to allow for proper healing in disease states such as infarction or failure of the heart.
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Affiliation(s)
- Kirill V Tarasov
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Khalid Chakir
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Daniel R Riordon
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Alexey E Lyashkov
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Ismayil Ahmet
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Maria Grazia Perino
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Allwin Jennifa Silvester
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Jing Zhang
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Mingyi Wang
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Yevgeniya O Lukyanenko
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Jia-Hua Qu
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Miguel Calvo-Rubio Barrera
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Magdalena Juhaszova
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Yelena S Tarasova
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Bruce Ziman
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Richard Telljohann
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Vikas Kumar
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Mark Ranek
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - John Lammons
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Rostislav Bychkov
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Rafael de Cabo
- Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Seungho Jun
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Gizem Keceli
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Ashish Gupta
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Dongmei Yang
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Miguel A Aon
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Luigi Adamo
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Christopher H Morrell
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Walter Otu
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Cameron Carroll
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Shane Chambers
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Thanh Huynh
- Section on Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Karel Pacak
- Section on Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Robert Weiss
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Loren Field
- Kraennert Institute of Cardiology, Indiana University School of MedicineIdianapolisUnited States
| | - Steven J Sollott
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of HealthBaltimoreUnited States
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7
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Zhai R, Snyder J, Montgomery S, Sato PY. Double life: How GRK2 and β-arrestin signaling participate in diseases. Cell Signal 2022; 94:110333. [PMID: 35430346 PMCID: PMC9929935 DOI: 10.1016/j.cellsig.2022.110333] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 11/03/2022]
Abstract
G-protein coupled receptor (GPCR) kinases (GRKs) and β-arrestins play key roles in GPCR and non-GPCR cellular responses. In fact, GRKs and arrestins are involved in a plethora of pathways vital for physiological maintenance of inter- and intracellular communication. Here we review decades of research literature spanning from the discovery, identification of key structural elements, and findings supporting the diverse roles of these proteins in GPCR-mediated pathways. We then describe how GRK2 and β-arrestins partake in non-GPCR signaling and briefly summarize their involvement in various pathologies. We conclude by presenting gaps in knowledge and our prospective on the promising pharmacological potential in targeting these proteins and/or downstream signaling. Future research is warranted and paramount for untangling these novel and promising roles for GRK2 and arrestins in metabolism and disease progression.
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Affiliation(s)
| | | | | | - Priscila Y. Sato
- Corresponding author at: Drexel University College of Medicine, Department of Pharmacology and Physiology, 245 N 15th Street, NCB 8152, Philadelphia, PA 19102, USA. (P.Y. Sato)
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8
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Khalid E, Chang JP. Receptor-proximal effectors mediating GnRH actions in the goldfish pituitary: Involvement of G protein subunits and GRKs. Gen Comp Endocrinol 2022; 319:113991. [PMID: 35157923 DOI: 10.1016/j.ygcen.2022.113991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/01/2022] [Accepted: 02/09/2022] [Indexed: 11/21/2022]
Abstract
In goldfish (Carassius auratus), two endogenous isoforms of gonadotropin-releasing hormone (GnRH) stimulate luteinizing hormone (LH) and growth hormone (GH) secretion. These isoforms, GnRH2 and GnRH3, act on a shared population of cell-surface GnRH receptors (GnRHRs) expressed on both gonadotrophs and somatotrophs, and can signal through unique, yet partially overlapping, suites of intracellular effectors, in a phenomenon known as functional selectivity or biased signalling. In this study, G-protein alpha (Gα) subunits were targeted with two inhibitors, YM-254890 and BIM-46187, to ascertain the contribution of specific G-protein subunits in GnRH signalling. Results with the Gαq/11-specific inhibitor YM-254890 on primary cultures of goldfish pituitary cells revealed the use of these subunits in GnRH control of both LH and GH release, as well as GnRH-induced elevations in phospho-ERK levels. Results with the pan-Gα inhibitor BIM-46187 matched those using YM-254890 in LH release but GH responses differed, indicating additional, non-Gαq/11 subunits may be involved in somatotrophs. BIM-46187 also elevated unstimulated LH and GH release suggesting that Gα subunits regulate basal hormone secretion. Furthermore, G-protein-coupled receptor kinase (GRK2/3) inhibition reduced LH responses to GnRH2 and GnRH3, and selectively enhanced GnRH2-stimulated GH release, indicating differential use of GRK2/3 in GnRH actions on gonadotrophs and somatotrophs. These findings in a primary untransformed system provide the first direct evidence to establish Gαq/11 as an obligate driver of GnRH signalling in goldfish pituitary cells, and additionally describe the differential agonist- and cell type-selective involvement of GRK2/3 in this system.
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Affiliation(s)
- Enezi Khalid
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G2E9, Canada
| | - John P Chang
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G2E9, Canada.
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9
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Cheng H, Guo P, Su T, Jiang C, Zhu Z, Wei W, Zhang L, Wang Q. G protein-coupled receptor kinase type 2 and β-arrestin2: Key players in immune cell functions and inflammation. Cell Signal 2022; 95:110337. [DOI: 10.1016/j.cellsig.2022.110337] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 04/15/2022] [Accepted: 04/15/2022] [Indexed: 02/07/2023]
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10
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Miao H, Vanderleest TE, Budhathoki R, Loerke D, Blankenship JT. A PtdIns(3,4,5)P 3 dispersal switch engages cell ratcheting at specific cell surfaces. Dev Cell 2021; 56:2579-2591.e4. [PMID: 34525342 DOI: 10.1016/j.devcel.2021.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 07/02/2021] [Accepted: 08/19/2021] [Indexed: 12/31/2022]
Abstract
Force generation in epithelial tissues is often pulsatile, with actomyosin networks generating contractile forces before cyclically disassembling. This pulsed nature of cytoskeletal forces implies that there must be ratcheting mechanisms that drive processive transformations in cell shape. Previous work has shown that force generation is coordinated with endocytic remodeling; however, how ratcheting becomes engaged at specific cell surfaces remains unclear. Here, we report that PtdIns(3,4,5)P3 is a critical lipid-based cue for ratcheting engagement. The Sbf RabGEF binds to PIP3, and disruption of PIP3 reveals a dramatic switching behavior in which medial ratcheting is activated and epithelial cells begin globally constricting apical surfaces. PIP3 enrichments are developmentally regulated, with mesodermal cells having high apical PIP3 while germband cells have higher interfacial PIP3. Finally, we show that JAK/STAT signaling constitutes a second pathway that combinatorially regulates Sbf/Rab35 recruitment. Our results elucidate a complex lipid-dependent regulatory machinery that directs ratcheting engagement in epithelial tissues.
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Affiliation(s)
- Hui Miao
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
| | | | - Rashmi Budhathoki
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA
| | - Dinah Loerke
- Department of Physics, University of Denver, Denver, CO 80208, USA
| | - J Todd Blankenship
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
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11
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Alonazi ASA, Willets JM. G protein-coupled receptor kinase 2 is essential to enable vasoconstrictor-mediated arterial smooth muscle proliferation. Cell Signal 2021; 88:110152. [PMID: 34555505 DOI: 10.1016/j.cellsig.2021.110152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/07/2021] [Accepted: 09/15/2021] [Indexed: 01/05/2023]
Abstract
Hypertension is associated with increased production and circulation of vasoconstrictors, resulting in enhanced signalling through their cognate G protein-coupled receptors (GPCR). Prolonged vasoconstrictor GPCR signalling increases arterial contraction and stimulates signalling pathways that promote vascular smooth muscle cell (VSMC) proliferation, contributing to the development of atherosclerotic plaques, re-stenosis lesions and vascular remodelling. GPCR signalling through phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) promotes VSMC proliferation. In VSMC, G protein-coupled receptor kinase 2 (GRK2) is known to regulate numerous vasoconstrictor GPCRs and their downstream signalling pathways. As GRK2 is implicated in controlling various aspects of cellular growth, we examined whether GRK2 could affect VSMC proliferation. Using two indices of cell growth, we show that PI3K inhibition and depletion of GRK2 expression produced a similar ablation of pro-proliferative vasoconstrictor-stimulated VSMC growth. Furthermore, GRK2-knockdown ablated the sustained phase of endothelin-1 and angiotensin-II-stimulated Akt phosphorylation, whilst the peak (5 min) phase was unaffected. Conversely, the GRK2 inhibitor compound 101 did not affect vasoconstrictor-driven Akt phosphorylation. Vasoconstrictor-stimulated phosphorylation of the Akt substrates GSK3α and GSK3β was ablated following RNAi-mediated GRK2 depletion, or after PI3K inhibition. Moreover, GRK2 knockdown prevented endothelin-1 and angiotensin-II from increasing cyclin D1 expression. These data suggest GRK2 expression is essential to facilitate vasoconstrictor-driven VSMC proliferation through its ability to promote efficient prolonged PI3K-Akt signalling, and thus relieve the GSK3-mediated block on cell cycling. Considering VSMC GRK2 expression increases early in the development of hypertension, this highlights the potential for GRK2 to promote VSMC growth and exacerbate hypertensive pathophysiological vascular remodelling.
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Affiliation(s)
- Asma S A Alonazi
- Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, United Kingdom; Department of Pharmacology and Toxicology, Pharmacy College, King Saud University, Riyadh, Saudi Arabia
| | - Jonathon M Willets
- Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, United Kingdom.
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12
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Kuai J, Han C, Wei W. Potential Regulatory Roles of GRK2 in Endothelial Cell Activity and Pathological Angiogenesis. Front Immunol 2021; 12:698424. [PMID: 34335610 PMCID: PMC8320431 DOI: 10.3389/fimmu.2021.698424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022] Open
Abstract
G protein-coupled receptor (GPCR) kinase 2 (GRK2) is an integrative node in many signaling network cascades. Emerging evidence indicates that GRK2 can interact with a large number of GPCRs and non-GPCR substrates in both kinase-dependent and -independent modes. Some of these pathways are associated with endothelial cell (EC) activity. The active state of ECs is a pivotal factor in angiogenesis. The occurrence and development of some inflammation-related diseases are accompanied by pathological angiogenesis, but there remains a lack of effective targeted treatments. Alterations in the expression and/or localization of GRK2 have been identified in several types of diseases and have been demonstrated to regulate the angiogenesis process in these diseases. GRK2 as a target may be a promising candidate for anti-angiogenesis therapy.
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Affiliation(s)
| | | | - Wei Wei
- Institute of Clinical Pharmacology, Key Laboratory of Anti-Inflammatory and Immune Medicine (Anhui Medical University), Ministry of Education, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Anhui Medical University, Hefei, China
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13
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Alhosaini K, Azhar A, Alonazi A, Al-Zoghaibi F. GPCRs: The most promiscuous druggable receptor of the mankind. Saudi Pharm J 2021; 29:539-551. [PMID: 34194261 PMCID: PMC8233523 DOI: 10.1016/j.jsps.2021.04.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
All physiological events in living organisms originated as specific chemical/biochemical signals on the cell surface and transmitted into the cytoplasm. This signal is translated within milliseconds-hours to a specific and unique order required to maintain optimum performance and homeostasis of living organisms. Examples of daily biological functions include neuronal communication and neurotransmission in the process of learning and memory, secretion (hormones, sweat, and saliva), muscle contraction, cellular growth, differentiation and migration during wound healing, and immunity to fight infections. Among the different transducers for such life-dependent signals is the large family of G protein-coupled receptors (GPCRs). GPCRs constitute roughly 800 genes, corresponding to 2% of the human genome. While GPCRs control a plethora of pathophysiological disorders, only approximately one-third of GPCR families have been deorphanized and characterized. Recent drug data show that around 40% of the recommended drugs available in the market target mainly GPCRs. In this review, we presented how such system signals, either through G protein or via other players, independent of G protein, function within the biological system. We also discussed drugs in the market or clinical trials targeting mainly GPCRs in various diseases, including cancer.
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Key Words
- AC, Adenylyl Cyclase
- Arrestin
- CCR, Chemokine Receptor
- COX, Cyclooxygenase
- DAG, Diacylglycerol
- Drugs
- ERK, Extracellular signal-Regulated Kinase
- G proteins
- GIP, Gastric Inhibitory Peptide
- GLP1R, Glucagon-Like Peptide-1 Receptor
- GPCR
- GRKs
- GRKs, G protein-coupled Receptor Kinases
- Heterodimerization
- IP3, Inositol 1,4,5-triphosphate
- MAPK, Mitogen-Activated Protein Kinase
- NMDA, N-Methyl D-Aspartate
- Nbs, Nanobodies
- PAR-1, Protease Activated Receptor 1
- PIP2, Phosphatidylinositol-4,5-bisphosphate
- PKA, Protein Kinase A
- Signaling
- cAMP, cyclic AMP
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Affiliation(s)
- Khaled Alhosaini
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Post Box 2457, Riyadh 11451, Saudi Arabia
| | - Asim Azhar
- Interdisciplinary Biotechnology Unit, AMU Aligarh, UP, India
| | - Asma Alonazi
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Post Box 2457, Riyadh 11451, Saudi Arabia
| | - F Al-Zoghaibi
- Molecular BioMedicine Program, Research Centre, King Faisal Specialist Hospital and Research Centre, P.O.Box: 3354, MBC:03, Riyadh 11211, Saudi Arabia
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14
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G q/11-dependent regulation of endosomal cAMP generation by parathyroid hormone class B GPCR. Proc Natl Acad Sci U S A 2020; 117:7455-7460. [PMID: 32184323 DOI: 10.1073/pnas.1918158117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
cAMP production upon activation of Gs by G protein-coupled receptors has classically been considered to be plasma membrane-delimited, but a shift in this paradigm has occurred in recent years with the identification of several receptors that continue to signal from early endosomes after internalization. The molecular mechanisms regulating this aspect of signaling remain incompletely understood. Here, we investigated the role of Gq/11 activation by the parathyroid hormone (PTH) type 1 receptor (PTHR) in mediating endosomal cAMP responses. Inhibition of Gq/11 signaling by FR900359 markedly reduced the duration of PTH-induced cAMP production, and this effect was mimicked in cells lacking endogenous Gαq/11 We determined that modulation of cAMP generation by Gq/11 occurs at the level of the heterotrimeric G protein via liberation of cell surface Gβγ subunits, which, in turn, act in a phosphoinositide-3 kinase-dependent manner to promote the assembly of PTHR-βarrestin-Gβγ signaling complexes that mediate endosomal cAMP responses. These results unveil insights into the spatiotemporal regulation of Gs-dependent cAMP signaling.
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15
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He X, Yan L, Wu Q, Zhang G, Zhou N. Ligand-dependent internalization of Bombyx mori tachykinin-related peptide receptor is regulated by PKC, GRK5 and β-arrestin2/BmKurtz. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118690. [PMID: 32112783 DOI: 10.1016/j.bbamcr.2020.118690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 02/18/2020] [Accepted: 02/23/2020] [Indexed: 10/24/2022]
Abstract
Tachykinin signaling system is present in both vertebrates and invertebrates, and functions as neuromodulator responsible for the regulation of various physiological processes. In human, the internalization of G protein-coupled receptors has been extensively characterized; however, the insect GPCR internalization has been rarely investigated. Here, we constructed two expression vectors of Bombyx tachykinin-related peptide receptor (BmTKRPR) fused with Enhanced Green Fluorescent Protein (EGFP) at the C-terminal end for direct visualization of receptor expression, localization, and trafficking in cultured mammalian HEK293 and insect Sf21 cells. Our results demonstrated that agonist-activated BmTKRPR underwent rapid internalization in a dose-and time-dependent manner via a clathrin-dependent pathway in both HEK293 and Sf21 cells. Further investigation via RNAi or specific inhibitors, or co-immunoprecipitation demonstrated that agonist-induced BmTKRPR internalization was mediated by PKC, GRK5 and β-arrestin2/BmKurtz. In addition, we also observed that most of the internalized BmTKRP receptors were recycled to the cell surface via early endosomes upon peptide ligand removal. Our study provides the first in-depth information on mechanisms underlying insect TKRP receptor internalization and perhaps aids in the interpretation of the signaling in the regulation of physiological processes.
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Affiliation(s)
- Xiaobai He
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China; College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China.
| | - Lili Yan
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qi Wu
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China
| | - Guozheng Zhang
- Key Laboratory of Genetic Improvement of Sericulture, Ministry of Agriculture and Rural Affairs, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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16
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Grove LM, Mohan ML, Abraham S, Scheraga RG, Southern BD, Crish JF, Naga Prasad SV, Olman MA. Translocation of TRPV4-PI3Kγ complexes to the plasma membrane drives myofibroblast transdifferentiation. Sci Signal 2019; 12:12/607/eaau1533. [PMID: 31719171 DOI: 10.1126/scisignal.aau1533] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Myofibroblasts are key contributors to pathological fibrotic conditions of several major organs. The transdifferentiation of fibroblasts into myofibroblasts requires both a mechanical signal and transforming growth factor-β (TGF-β) signaling. The cation channel transient receptor potential vanilloid 4 (TRPV4) is a critical mediator of myofibroblast transdifferentiation and in vivo fibrosis through its mechanosensitivity to extracellular matrix stiffness. Here, we showed that TRPV4 promoted the transdifferentiation of human and mouse lung fibroblasts through its interaction with phosphoinositide 3-kinase γ (PI3Kγ), forming nanomolar-affinity, intracellular TRPV4-PI3Kγ complexes. TGF-β induced the recruitment of TRPV4-PI3Kγ complexes to the plasma membrane and increased the activities of both TRPV4 and PI3Kγ. Using gain- and loss-of-function approaches, we showed that both TRPV4 and PI3Kγ were required for myofibroblast transdifferentiation as assessed by the increased production of α-smooth muscle actin and its incorporation into stress fibers, cytoskeletal changes, collagen-1 production, and contractile force. Expression of various mutant forms of the PI3Kγ catalytic subunit (p110γ) in cells lacking PI3Kγ revealed that only the noncatalytic, amino-terminal domain of p110γ was necessary and sufficient for TGF-β-induced TRPV4 plasma membrane recruitment and myofibroblast transdifferentiation. These data suggest that TGF-β stimulates a noncanonical scaffolding action of PI3Kγ, which recruits TRPV4-PI3Kγ complexes to the plasma membrane, thereby increasing myofibroblast transdifferentiation. Given that both TRPV4 and PI3Kγ have pleiotropic actions, targeting the interaction between them could provide a specific therapeutic approach for inhibiting myofibroblast transdifferentiation.
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Affiliation(s)
- Lisa M Grove
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Maradumane L Mohan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Susamma Abraham
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Rachel G Scheraga
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Brian D Southern
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - James F Crish
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Sathyamangla V Naga Prasad
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Mitchell A Olman
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA. .,Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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17
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Xu W, Reith MEA, Liu-Chen LY, Kortagere S. Biased signaling agonist of dopamine D3 receptor induces receptor internalization independent of β-arrestin recruitment. Pharmacol Res 2019; 143:48-57. [PMID: 30844536 DOI: 10.1016/j.phrs.2019.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Agonist-induced internalization of G protein-coupled receptors (GPCRs) is a significant step in receptor kinetics and is known to be involved in receptor down-regulation. However, the dopamine D3 receptor (D3R) has been an exception wherein agonist induces D3Rs to undergo desensitization followed by pharmacological sequestration - which is defined as the sequestration of cell surface receptors into a more hydrophobic fraction within the plasma membrane without undergoing the process of receptor internalization. Pharmacological sequestration renders the receptor in an inactive state on the membrane. In our previous study we demonstrated that a novel class of D3R agonists exemplified by SK608 have biased signaling properties via the G-protein dependent pathway and do not induce D3R desensitization. In this study, using radioligand binding assay, immunoblot or immunocytochemistry methods, we observed that SK608 induced internalization of human D3R stably expressed in CHO, HEK and SH-SY5Y cells which are derived from neuroblastoma cells, suggesting that it is not a cell-type specific event. Further, we have evaluated the potential mechanism of D3R internalization induced by these biased signaling agonists. SK608-induced D3R internalization was time- and concentration-dependent. In comparison, dopamine induced D3R upregulation and pharmacological sequestration in the same assays. GRK2 and clathrin/dynamin I/II are the key molecular players in the SK608-induced D3R internalization process, while β-arrestin 1/2 and GRK-interacting protein 1(GIT1) are not involved. These results suggest that SK608-promoted D3R internalization is similar to the type II internalization observed among peptide binding GPCRs.
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Affiliation(s)
- Wei Xu
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States
| | - Maarten E A Reith
- Department of Psychiatry, Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, United States
| | - Lee-Yuan Liu-Chen
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, United States
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States; Department of Pharmacology and Physiology, Drexel University College of Medicine, PA 19102, United States.
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18
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New Player in Endosomal Trafficking: Differential Roles of Smad Anchor for Receptor Activation (SARA) Protein. Mol Cell Biol 2018; 38:MCB.00446-18. [PMID: 30275343 DOI: 10.1128/mcb.00446-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The development and maintenance of multicellular organisms require specialized coordination between external cellular signals and the proteins receiving stimuli and regulating responses. A critical role in the proper functioning of these processes is played by endosomal trafficking, which enables the transport of proteins to targeted sites as well as their return to the plasma membrane through its essential components, the endosomes. During this trafficking, signaling pathways controlling functions related to the endosomal system are activated both directly and indirectly. Although there are a considerable number of molecules participating in these processes, some are more known than others for their specific functions. Toward the end of the 1990s, Smad anchor for receptor activation (SARA) protein was described to be controlling and to facilitate the localization of Smads to transforming growth factor β (TGF-β) receptors during TGF-β signaling activation, and, strikingly, SARA was also identified to be one of the proteins that bind to early endosomes (EEs) participating in membrane trafficking in several cell models. The purpose of this review is to analyze the state of the art of the contribution of SARA in different cell types and cellular contexts, focusing on the biological role of SARA in two main processes, trafficking and cellular signaling, both of which are necessary for intercellular coordination, communication, and development.
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19
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The role of G protein-coupled receptor kinases in the pathology of malignant tumors. Acta Pharmacol Sin 2018; 39:1699-1705. [PMID: 29921886 DOI: 10.1038/s41401-018-0049-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/20/2018] [Indexed: 12/28/2022] Open
Abstract
G protein-coupled receptor kinases (GRKs) constitute seven subtypes of serine/threonine protein kinases that specifically recognize and phosphorylate agonist-activated G protein-coupled receptors (GPCRs), thereby terminating the GPCRs-mediated signal transduction pathway. Recent research shows that GRKs also interact with non-GPCRs and participate in signal transduction in non-phosphorylated manner. Besides, GRKs activity can be regulated by multiple factors. Changes in GRKs expression have featured prominently in various tumor pathologies, and they are associated with angiogenesis, proliferation, migration, and invasion of malignant tumors. As a result, GRKs have been intensively studied as potential therapeutic targets. Herein, we review evolving understanding of the function of GRKs, the regulation of GRKs activity and the role of GRKs in human malignant tumor pathophysiology.
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20
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Qian W, Yu D, Zhang J, Hu Q, Tang C, Liu P, Ye P, Wang X, Lv Q, Chen M, Sheng L. Wogonin Attenuates Isoprenaline-Induced Myocardial Hypertrophy in Mice by Suppressing the PI3K/Akt Pathway. Front Pharmacol 2018; 9:896. [PMID: 30150938 PMCID: PMC6099096 DOI: 10.3389/fphar.2018.00896] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 07/23/2018] [Indexed: 12/21/2022] Open
Abstract
Many studies have focused on identifying therapeutic targets of myocardial hypertrophy for the treatment of correlative cardiac events. Wogonin is a natural flavonoid compound that displays a potent anti-hypertrophic effect. Knowledge of its pharmacological mechanisms might reveal an effective way to search for therapeutic targets. Myocardial hypertrophy was replicated by the subcutaneous implantation of an isoprenaline mini-pump in mice or isoprenaline treatment of H9C2 cells. Pathologic changes in cardiac structure were assessed by echocardiographic and histological examinations. The signaling transduction in hypertrophy-promoting pathways and the genes involved were detected by western blot and RT-qPCR. Wogonin significantly attenuated isoprenaline-induced myocardial hypertrophy in vivo and in vitro by suppressing phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) hypertrophy-promoting pathway. Wogonin promoted the ubiquitination and degradation of PI3K catalytic subunit alpha (Pik3ca), the catalytic subunit of PI3K, which was upregulated by isoprenaline treatment. Wogonin also increased the expression of neural precursor cells expressing developmentally down-regulated gene 4-like (Nedd4l), the ubiquitin E3 ligase of Pik3ca. Therefore, wogonin targets Nedd4l to induce the degradation of Pik3ca, which reverses the over-activation of the PI3K/Akt pathway and consequently relieves the isoprenaline-induced myocardial hypertrophy.
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Affiliation(s)
- Weichun Qian
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Dongsheng Yu
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Jia Zhang
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Qiaoyun Hu
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Chuanfeng Tang
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Peiyu Liu
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Peng Ye
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Xiaoli Wang
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Qiu Lv
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Minglong Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Liang Sheng
- Department of Pharmacology, School of Basic Medical Science, Nanjing Medical University, Nanjing, China.,Key Laboratory of Rare Metabolic Diseases, Nanjing Medical University, Nanjing, China.,Neuroprotective Drug Discovery Key Laboratory, Nanjing Medical University, Nanjing, China
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21
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Wang HJ, Gu HX, Eijkelkamp N, Heijnen CJ, Kavelaars A. Low GRK2 Underlies Hyperalgesic Priming by Glial Cell-Derived Neurotrophic Factor. Front Pharmacol 2018; 9:592. [PMID: 29922165 PMCID: PMC5996251 DOI: 10.3389/fphar.2018.00592] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/17/2018] [Indexed: 11/13/2022] Open
Abstract
Background: We recently identified the balance between the level of G protein coupled receptor kinase 2 (GRK2) and Epac1 in nociceptors as a key factor in the transition from acute to chronic pain that occurs in mice 'primed' by an inflammatory stimulus. Here, we examined the contribution of GRK2 and Epac-signaling to growth factor-induced hyperalgesic priming. Methods: Mice were primed by intraplantar injection with glial cell-derived neurotrophic factor (GDNF). Mechanical allodynia in response to PGE2 was followed over time in primed and non-primed animals. GRK2 protein levels in dorsal root ganglion (DRG) neurons were quantified by immunohistochemistry. The effect of herpes simplex virus (HSV)-GRK2 amplicons to restore GRK2 levels or of an Epac inhibitor on PGE2 allodynia in primed mice was examined. Results: Glial cell-derived neurotrophic factor-induced hyperalgesia disappeared within 12 days. The hyperalgesic response to a subsequent intraplantar injection of PGE2 was prolonged from <24 h in control mice to more than 72 h in GDNF-primed mice. In male and female primed mice, PGE2 hyperalgesia was inhibited by oral administration of the Epac inhibitor ESI-09, while the drug had no effect in control mice. Mice primed with GDNF had reduced levels of GRK2 in IB4(+) small DRG neurons, but normal GRK2 levels in IB4(-) DRG neurons. Intraplantar administration of HSV-GRK2 amplicons to increase GRK2 protein levels prevented the prolongation of PGE2-induced hyperalgesia in GDNF-primed mice. Conclusion: Low GRK2 in nociceptors is critical to develop a primed state in response to GDNF and leads to engagement of Epac signaling and transition to chronic PGE2-induced hyperalgesia. Increasing GRK2 protein or inhibiting Epac signaling may represent new avenues for preventing transition to a chronic pain state.
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Affiliation(s)
- Hui-Jing Wang
- Laboratory of Neuropsychopharmacology, College of Fundamental Medicine, Shanghai University of Medicine & Health Science, Shanghai, China.,Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, Utrecht, Netherlands
| | - Han-Xin Gu
- Laboratory of Neuropsychopharmacology, College of Fundamental Medicine, Shanghai University of Medicine & Health Science, Shanghai, China
| | - Niels Eijkelkamp
- Laboratory of Neuroimmunology and Developmental Origins of Disease, University Medical Center Utrecht, Utrecht, Netherlands
| | - Cobi J Heijnen
- Division of Internal Medicine, Laboratory of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Annemieke Kavelaars
- Division of Internal Medicine, Laboratory of Neuroimmunology, Department of Symptom Research, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
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22
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Abstract
Diabetes is a major risk factor for the development of heart failure. One of the hallmarks of diabetes is insulin resistance associated with hyperinsulinemia. The literature shows that insulin and adrenergic signaling is intimately linked to each other; however, whether and how insulin may modulate cardiac adrenergic signaling and cardiac function remains unknown. Notably, recent studies have revealed that insulin receptor and β2 adrenergic receptor (β2AR) forms a membrane complex in animal hearts, bringing together the direct contact between 2 receptor signaling systems, and forming an integrated and dynamic network. Moreover, insulin can drive cardiac adrenergic desensitization via protein kinase A and G protein-receptor kinases phosphorylation of the β2AR, which compromises adrenergic regulation of cardiac contractile function. In this review, we will explore the current state of knowledge linking insulin and G protein-coupled receptor signaling, especially β-adrenergic receptor signaling in the heart, with emphasis on molecular insights regarding its role in diabetic cardiomyopathy.
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23
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Teoh JP, Bayoumi AS, Aonuma T, Xu Y, Johnson JA, Su H, Weintraub NL, Tang Y, Kim IM. β-arrestin-biased agonism of β-adrenergic receptor regulates Dicer-mediated microRNA maturation to promote cardioprotective signaling. J Mol Cell Cardiol 2018; 118:225-236. [PMID: 29627294 DOI: 10.1016/j.yjmcc.2018.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 12/20/2022]
Abstract
RATIONALE MicroRNAs (miRs) are small, non-coding RNAs that function to post-transcriptionally regulate target genes. First transcribed as primary miR transcripts (pri-miRs), they are enzymatically processed by Drosha into premature miRs (pre-miRs) and further cleaved by Dicer into mature miRs. Initially discovered to desensitize β-adrenergic receptor (βAR) signaling, β-arrestins are now well-appreciated to modulate multiple pathways independent of G protein signaling, a concept known as biased signaling. Using the β-arrestin-biased βAR ligand carvedilol, we previously showed that β-arrestin1 (not β-arrestin2)-biased β1AR (not β2AR) cardioprotective signaling stimulates Drosha-mediated processing of six miRs by forming a multi-protein nuclear complex, which includes β-arrestin1, the Drosha microprocessor complex and a single-stranded RNA binding protein hnRNPA1. OBJECTIVE Here, we investigate whether β-arrestin-mediated βAR signaling induced by carvedilol could regulate Dicer-mediated miR maturation in the cytoplasm and whether this novel mechanism promotes cardioprotective signaling. METHODS AND RESULTS In mouse hearts, carvedilol indeed upregulates three mature miRs, but not their pre-miRs and pri-miRs, in a β-arrestin 1- or 2-dependent manner. Interestingly, carvedilol-mediated activation of miR-466g or miR-532-5p, and miR-674 is dependent on β2ARs and β1ARs, respectively. Mechanistically, β-arrestin 1 or 2 regulates maturation of three newly identified βAR/β-arrestin-responsive miRs (β-miRs) by associating with the Dicer maturation RNase III enzyme on three pre-miRs of β-miRs. Myocardial cell approaches uncover that despite their distinct roles in different cell types, β-miRs act as gatekeepers of cardiac cell functions by repressing deleterious targets. CONCLUSIONS Our findings indicate a novel role for βAR-mediated β-arrestin signaling activated by carvedilol in Dicer-mediated miR maturation, which may be linked to its protective mechanisms.
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Affiliation(s)
- Jian-Peng Teoh
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA
| | - Ahmed S Bayoumi
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA
| | - Tatsuya Aonuma
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA
| | - Yanyan Xu
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA
| | - John A Johnson
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA 30912, USA
| | - Huabo Su
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Pharmacology and Toxicology, Augusta University, Augusta, GA 30912, USA
| | - Neal L Weintraub
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Medicine, Augusta University, Augusta, GA 30912, USA
| | - Yaoliang Tang
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Medicine, Augusta University, Augusta, GA 30912, USA
| | - Il-Man Kim
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA; Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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24
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Wang J, Hanada K, Staus DP, Makara MA, Dahal GR, Chen Q, Ahles A, Engelhardt S, Rockman HA. Gα i is required for carvedilol-induced β 1 adrenergic receptor β-arrestin biased signaling. Nat Commun 2017; 8:1706. [PMID: 29167435 PMCID: PMC5700200 DOI: 10.1038/s41467-017-01855-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 10/19/2017] [Indexed: 12/12/2022] Open
Abstract
The β1 adrenergic receptor (β1AR) is recognized as a classical Gαs-coupled receptor. Agonist binding not only initiates G protein-mediated signaling but also signaling through the multifunctional adapter protein β-arrestin. Some βAR ligands, such as carvedilol, stimulate βAR signaling preferentially through β-arrestin, a concept known as β-arrestin-biased agonism. Here, we identify a signaling mechanism, unlike that previously known for any Gαs-coupled receptor, whereby carvedilol induces the transition of the β1AR from a classical Gαs-coupled receptor to a Gαi-coupled receptor stabilizing a distinct receptor conformation to initiate β-arrestin-mediated signaling. Recruitment of Gαi is not induced by any other βAR ligand screened, nor is it required for β-arrestin-bias activated by the β2AR subtype of the βAR family. Our findings demonstrate a previously unrecognized role for Gαi in β1AR signaling and suggest that the concept of β-arrestin-bias may need to be refined to incorporate the selective bias of receptors towards distinct G protein subtypes.
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Affiliation(s)
- Jialu Wang
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Kenji Hanada
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Dean P Staus
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Michael A Makara
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Giri Raj Dahal
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Qiang Chen
- Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Andrea Ahles
- Institute of Pharmacology and Toxicology, Technical University of Munich, Munich, 80802, Germany
| | - Stefan Engelhardt
- Institute of Pharmacology and Toxicology, Technical University of Munich, Munich, 80802, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, 80802, Germany
| | - Howard A Rockman
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA. .,Department of Medicine, Duke University Medical Center, Durham, NC, 27710, USA. .,Departments of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA.
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25
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Mohan ML, Chatterjee A, Ganapathy S, Mukherjee S, Srikanthan S, Jolly GP, Anand RS, Naga Prasad SV. Noncanonical regulation of insulin-mediated ERK activation by phosphoinositide 3-kinase γ. Mol Biol Cell 2017; 28:3112-3122. [PMID: 28877982 PMCID: PMC5662266 DOI: 10.1091/mbc.e16-12-0864] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 08/23/2017] [Accepted: 08/31/2017] [Indexed: 12/17/2022] Open
Abstract
Classically, Class IB phosphoinositide 3-kinase (PI3Kγ) plays a role in ERK activation following G-protein–coupled receptor (GPCR) activation. Here we show that PI3Kγ noncanonically regulates ERK phosphorylation in a kinase-independent mechanism, irrespective of the upstream signals. PI3Kγ sequesters PP2A, allowing sustained ERK function. Classically Class IB phosphoinositide 3-kinase (PI3Kγ) plays a role in extracellular signal–regulated kinase (ERK) activation following G-protein coupled receptor (GPCR) activation. Knock-down of PI3Kγ unexpectedly resulted in loss of ERK activation to receptor tyrosine kinase agonists such as epidermal growth factor or insulin. Mouse embryonic fibroblasts (MEFs) or primary adult cardiac fibroblasts isolated from PI3Kγ knock-out mice (PI3KγKO) showed decreased insulin-stimulated ERK activation. However, expression of kinase-dead PI3Kγ resulted in rescue of insulin-stimulated ERK activation. Mechanistically, PI3Kγ sequesters protein phosphatase 2A (PP2A), disrupting ERK–PP2A interaction, as evidenced by increased ERK–PP2A interaction and associated PP2A activity in PI3KγKO MEFs, resulting in decreased ERK activation. Furthermore, β-blocker carvedilol-mediated β-arrestin-dependent ERK activation is significantly reduced in PI3KγKO MEF, suggesting accelerated dephosphorylation. Thus, instead of classically mediating the kinase arm, PI3Kγ inhibits PP2A by scaffolding and sequestering, playing a key parallel synergistic step in sustaining the function of ERK, a nodal enzyme in multiple cellular processes.
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Affiliation(s)
- Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Arunachal Chatterjee
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Swetha Ganapathy
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Sromona Mukherjee
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Sowmya Srikanthan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - George P Jolly
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Rohit S Anand
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Sathyamangla V Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
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26
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Nieuwoudt S, Mulya A, Fealy CE, Martelli E, Dasarathy S, Naga Prasad SV, Kirwan JP. In vitro contraction protects against palmitate-induced insulin resistance in C2C12 myotubes. Am J Physiol Cell Physiol 2017; 313:C575-C583. [PMID: 28835436 DOI: 10.1152/ajpcell.00123.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/16/2017] [Accepted: 08/21/2017] [Indexed: 12/13/2022]
Abstract
We are interested in understanding mechanisms that govern the protective role of exercise against lipid-induced insulin resistance, a key driver of type 2 diabetes. In this context, cell culture models provide a level of abstraction that aid in our understanding of cellular physiology. Here we describe the development of an in vitro myotube contraction system that provides this protective effect, and which we have harnessed to investigate lipid-induced insulin resistance. C2C12 myocytes were differentiated into contractile myotubes. A custom manufactured platinum electrode system and pulse stimulator, with polarity switching, provided an electrical pulse stimulus (EPS) (1 Hz, 6-ms pulse width, 1.5 V/mm, 16 h). Contractility was assessed by optical flow flied spot noise mapping and inhibited by application of ammonium acetate. Following EPS, myotubes were challenged with 0.5 mM palmitate for 4 h. Cells were then treated with or without insulin for glucose uptake (30 min), secondary insulin signaling activation (10 min), and phosphoinositide 3-kinase-α (PI3Kα) activity (5 min). Prolonged EPS increased non-insulin-stimulated glucose uptake (83%, P = 0.002), Akt (Thr308) phosphorylation (P = 0.005), and insulin receptor substrate-1 (IRS-1)-associated PI3Kα activity (P = 0.048). Palmitate reduced insulin-specific action on glucose uptake (-49%, P < 0.001) and inhibited insulin-stimulated Akt phosphorylation (P = 0.049) and whole cell PI3Kα activity (P = 0.009). The inhibitory effects of palmitate were completely absent with EPS pretreatment at the levels of glucose uptake, insulin responsiveness, Akt phosphorylation, and whole cell PI3Kα activity. This model suggests that muscle contraction alone is a sufficient stimulus to protect against lipid-induced insulin resistance as evidenced by changes in the proximal canonical insulin-signaling pathway.
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Affiliation(s)
- Stephan Nieuwoudt
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio.,Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
| | - Anny Mulya
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
| | - Ciarán E Fealy
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
| | - Elizabeth Martelli
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Srinivasan Dasarathy
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
| | | | - John P Kirwan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio; .,Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; and
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27
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Bera A, Sen D. Promise of adeno-associated virus as a gene therapy vector for cardiovascular diseases. Heart Fail Rev 2017; 22:795-823. [DOI: 10.1007/s10741-017-9622-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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28
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Shi Q, Li M, Mika D, Fu Q, Kim S, Phan J, Shen A, Vandecasteele G, Xiang YK. Heterologous desensitization of cardiac β-adrenergic signal via hormone-induced βAR/arrestin/PDE4 complexes. Cardiovasc Res 2017; 113:656-670. [PMID: 28339772 PMCID: PMC5852637 DOI: 10.1093/cvr/cvx036] [Citation(s) in RCA: 35] [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: 05/02/2016] [Revised: 10/20/2017] [Accepted: 02/17/2017] [Indexed: 12/22/2022] Open
Abstract
AIMS Cardiac β-adrenergic receptor (βAR) signalling is susceptible to heterologous desensitization by different neurohormonal stimuli in clinical conditions associated with heart failure. We aim to examine the underlying mechanism of cross talk between βARs and a set of G-protein coupled receptors (GPCRs) activated by hormones/agonists. METHODS AND RESULTS Rat ventricular cardiomyocytes were used to determine heterologous phosphorylation of βARs under a series of GPCR agonists. Activation of Gs-coupled dopamine receptor, adenosine receptor, relaxin receptor and prostaglandin E2 receptor, and Gq-coupled α1 adrenergic receptor and angiotensin II type 1 receptor promotes phosphorylation of β1AR and β2AR at putative protein kinase A (PKA) phosphorylation sites; but activation of Gi-coupled α2 adrenergic receptor and activation of protease-activated receptor does not. The GPCR agonists that promote β2AR phosphorylation effectively inhibit βAR agonist isoproterenol-induced PKA phosphorylation of phospholamban and contractile function in ventricular cardiomyocytes. Heterologous GPCR stimuli have minimal to small effect on isoproterenol-induced β2AR activation and G-protein coupling for cyclic adenosine monophosphate (cAMP) production. However, these GPCR stimuli significantly promote phosphorylation of phosphodiesterase 4D (PDE4D), and recruit PDE4D to the phosphorylated β2AR in a β-arrestin 2 dependent manner without promoting β2AR endocytosis. The increased binding between β2AR and PDE4D effectively hydrolyzes cAMP signal generated by subsequent stimulation with isoproterenol. Mutation of PKA phosphorylation sites in β2AR, inhibition of PDE4, or genetic ablation of PDE4D or β-arrestin 2 abolishes this heterologous inhibitory effect. Ablation of β-arrestin 2 or PDE4D gene also rescues β-adrenergic stimuli-induced myocyte contractile function. CONCLUSIONS These data reveal essential roles of β-arrestin 2 and PDE4D in a common mechanism for heterologous desensitization of cardiac βARs under hormonal stimulation, which is associated with impaired cardiac function during the development of pathophysiological conditions.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 4/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism
- Hormones/pharmacology
- Male
- Mice, Knockout
- Myocardial Contraction/drug effects
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Phosphorylation
- Protein Kinase C/metabolism
- Rats
- Receptor Cross-Talk
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/drug effects
- Time Factors
- beta-Arrestin 1/genetics
- beta-Arrestin 1/metabolism
- beta-Arrestin 2/genetics
- beta-Arrestin 2/metabolism
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Affiliation(s)
- Qian Shi
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Minghui Li
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing 210001, China
| | - Delphine Mika
- INSERM UMR-S 1180, Univ. Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Qin Fu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Technology and Sciences, Wuhan 430030, China
| | - Sungjin Kim
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Jason Phan
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | - Ao Shen
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
| | | | - Yang K. Xiang
- Department of Pharmacology, University of California at Davis, Davis, CA 95616, USA
- VA Northern California Health care system, Mather, CA 95655, USA
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29
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Scaffolding Function of PI3Kgamma Emerges from Enzyme's Shadow. J Mol Biol 2017; 429:763-772. [PMID: 28179187 DOI: 10.1016/j.jmb.2017.01.023] [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] [Received: 09/27/2016] [Revised: 01/12/2017] [Accepted: 01/31/2017] [Indexed: 11/20/2022]
Abstract
Traditionally, an enzyme is a protein that mediates biochemical action by binding to the substrate and by catalyzing the reaction that translates external cues into biological responses. Sequential dissemination of information from one enzyme to another facilitates signal transduction in biological systems providing for feed-forward and feed-back mechanisms. Given this viewpoint, an enzyme without its catalytic activity is generally considered to be an inert organizational protein without catalytic function and has classically been termed as pseudo-enzymes. However, pseudo-enzymes still have biological function albeit non-enzymatic like serving as a chaperone protein or an interactive platform between proteins. In this regard, majority of the studies have focused solely on the catalytic role of enzymes in biological function, overlooking the potentially critical non-enzymatic roles. Increasing evidence from recent studies implicate that the scaffolding function of enzymes could be as important in signal transduction as its catalytic activity, which is an antithesis to the definition of enzymes. Recognition of non-enzymatic functions could be critical, as these unappreciated roles may hold clues to the ineffectiveness of kinase inhibitors in pathology, which is characteristically associated with increased enzyme expression. Using an established enzyme phosphoinositide 3-kinase γ, we discuss the insights obtained from the scaffolding function and how this non-canonical role could contribute to/alter the outcomes in pathology like cancer and heart failure. Also, we hope that with this review, we provide a forum and a starting point to discuss the idea that catalytic function alone may not account for all the actions observed with increased expression of the enzyme.
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30
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Zhang Y, Han D, Yu P, Huang Q, Ge P. Genome-scale transcriptional analysis reveals key genes associated with the development of type II diabetes in mice. Exp Ther Med 2017; 13:1044-1150. [PMID: 28450939 DOI: 10.3892/etm.2017.4042] [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] [Received: 09/22/2015] [Accepted: 11/09/2016] [Indexed: 11/06/2022] Open
Abstract
Diabetes mellitus is one of the primary diseases that pose a threat to human health. The focus of the present study is type II diabetes (T2D), which is caused by obesity and is the most prevalent type of diabetes. However, genome-scale transcriptional analysis of diabetic liver in the development process of T2D is yet to be further elucidated. Microassays were performed on liver tissue samples from three-, six- and nine-week-old db/db mice with diabetes and db/m mice to investigate differentially expressed mRNA. Based on the results of genome-scale transcriptional analysis, five genes were screened in the present study: chromobox 8 (CBX8), de-etiolated homolog 1 and damage specific DNA binding protein 1 associated 1 (DDA1), Phosphoinositide-3-kinase regulatory subunit 6 (PIK3R6), WD repeat domain 41 (WDR41) and Glycine Amidinotransferase (GATM). At three weeks of age, no significant differences in levels or ratios of expression were observed. However, at six and nine weeks, expression of CBX8, DDA1, PIK3R6 and WDR41 was significantly upregulated (P<0.05) in the db/db model group compared with the control group, whereas GATM expression was significantly downregulated (P<0.05). These results suggest that T2D-related differential expression of genes becomes more marked with age, which was confirmed via reverse transcription-quantitative polymerase chain reaction. Genome-scale transcriptional analysis in diabetic mice provided a novel insight into the molecular. events associated with the role of mRNAs in T2D development, with specific emphasis upon CBX8, DDA1, PIK3R6, GATM and WDR41. The results of the present study may provide rationale for the investigation of the target genes of these mRNAs in future studies.
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Affiliation(s)
- Yuchi Zhang
- Department of Pharmacology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Dongwei Han
- Department of Pharmacology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Pengyang Yu
- Department of Pharmacology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Qijing Huang
- Department of Pharmacology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China
| | - Pengling Ge
- Department of Pharmacology, School of Basic Medical Sciences, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang 150040, P.R. China.,The Key Laboratory of Myocardial Ischemia, Harbin Medical University of Chinese Ministry of Education, Harbin, Heilongjiang 150086, P.R. China
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31
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Bhattacharya S, McElhanon KE, Gushchina LV, Weisleder N. Role of phosphatidylinositol-4,5-bisphosphate 3-kinase signaling in vesicular trafficking. Life Sci 2016; 167:39-45. [PMID: 27760304 DOI: 10.1016/j.lfs.2016.10.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 02/07/2023]
Abstract
Phosphatidylinositol-4,5-bisphosphate 3-kinases (PI3Ks) are regulatory enzymes involved in the generation of lipid species that modulate cellular signaling pathways through downstream effectors to influence a variety of cellular functions. Years of intensive study of PI3Ks have produced a significant body of literature in many areas, including that PI3K can mediate intracellular vesicular trafficking and through these actions contribute to a number of important physiological functions. This review focuses on the crucial roles that PI3K and AKT, a major downstream partner of PI3K, play in the regulation of vesicle trafficking during various forms of vesicular endocytosis and exocytosis.
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Affiliation(s)
- Sayak Bhattacharya
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W. 12th Ave., Columbus, OH 43210-1252, United States
| | - Kevin E McElhanon
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W. 12th Ave., Columbus, OH 43210-1252, United States
| | - Liubov V Gushchina
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W. 12th Ave., Columbus, OH 43210-1252, United States
| | - Noah Weisleder
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 473 W. 12th Ave., Columbus, OH 43210-1252, United States.
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32
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Watson LJ, Alexander KM, Mohan ML, Bowman AL, Mangmool S, Xiao K, Naga Prasad SV, Rockman HA. Phosphorylation of Src by phosphoinositide 3-kinase regulates beta-adrenergic receptor-mediated EGFR transactivation. Cell Signal 2016; 28:1580-92. [PMID: 27169346 DOI: 10.1016/j.cellsig.2016.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 05/03/2016] [Accepted: 05/05/2016] [Indexed: 01/08/2023]
Abstract
β2-Adrenergic receptors (β2AR) transactivate epidermal growth factor receptors (EGFR) through formation of a β2AR-EGFR complex that requires activation of Src to mediate signaling. Here, we show that both lipid and protein kinase activities of the bifunctional phosphoinositide 3-kinase (PI3K) enzyme are required for β2AR-stimulated EGFR transactivation. Mechanistically, the generation of phosphatidylinositol (3,4,5)-tris-phosphate (PIP3) by the lipid kinase function stabilizes β2AR-EGFR complexes while the protein kinase activity of PI3K regulates Src activation by direct phosphorylation. The protein kinase activity of PI3K phosphorylates serine residue 70 on Src to enhance its activity and induce EGFR transactivation following βAR stimulation. This newly identified function for PI3K, whereby Src is a substrate for the protein kinase activity of PI3K, is of importance since Src plays a key role in pathological and physiological signaling.
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Affiliation(s)
- Lewis J Watson
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States
| | - Kevin M Alexander
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States
| | - Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States
| | - Amber L Bowman
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States
| | - Supachoke Mangmool
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Thailand
| | - Kunhong Xiao
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States; Department of Pharmacology and Chemical Biology, University of Pittsburg School of Medicine, Pittsburgh, PA 15261, United States
| | - Sathyamangla V Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States.
| | - Howard A Rockman
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States; Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, United States; Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, United States.
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33
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Marat AL, Haucke V. Phosphatidylinositol 3-phosphates-at the interface between cell signalling and membrane traffic. EMBO J 2016; 35:561-79. [PMID: 26888746 DOI: 10.15252/embj.201593564] [Citation(s) in RCA: 183] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/26/2016] [Indexed: 12/31/2022] Open
Abstract
Phosphoinositides (PIs) form a minor class of phospholipids with crucial functions in cell physiology, ranging from cell signalling and motility to a role as signposts of compartmental membrane identity. Phosphatidylinositol 3-phosphates are present at the plasma membrane and within the endolysosomal system, where they serve as key regulators of both cell signalling and of intracellular membrane traffic. Here, we provide an overview of the metabolic pathways that regulate cellular synthesis of PI 3-phosphates at distinct intracellular sites and discuss the mechanisms by which these lipids regulate cell signalling and membrane traffic. Finally, we provide a framework for how PI 3-phosphate metabolism is integrated into the cellular network.
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Affiliation(s)
- Andrea L Marat
- Leibniz Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
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Posor Y, Eichhorn-Grünig M, Haucke V. Phosphoinositides in endocytosis. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:794-804. [DOI: 10.1016/j.bbalip.2014.09.014] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/21/2014] [Accepted: 09/17/2014] [Indexed: 02/04/2023]
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PI3K-C2α: One enzyme for two products coupling vesicle trafficking and signal transduction. FEBS Lett 2015; 589:1552-8. [DOI: 10.1016/j.febslet.2015.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/04/2015] [Accepted: 05/05/2015] [Indexed: 12/20/2022]
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Trafficking of β-Adrenergic Receptors: Implications in Intracellular Receptor Signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 132:151-88. [PMID: 26055058 DOI: 10.1016/bs.pmbts.2015.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
β-Adrenergic receptors (βARs), prototypical G-protein-coupled receptors, play a pivotal role in regulating neuronal and cardiovascular responses to catecholamines during stress. Agonist-induced receptor endocytosis is traditionally considered as a primary mechanism to turn off the receptor signaling (or receptor desensitization). However, recent progress suggests that intracellular trafficking of βAR presents a mean to translocate receptor signaling machinery to intracellular organelles/compartments while terminating the signaling at the cell surface. Moreover, the apparent multidimensionality of ligand efficacy in space and time in a cell has forecasted exciting pathophysiological implications, which are just beginning to be explored. As we begin to understand how these pathways impact downstream cellular programs, this will have significant implications for a number of pathophysiological conditions in heart and other systems, that in turn open up new therapeutic opportunities.
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Davis A, Abraham E, McEvoy E, Sonnenfeld S, Lewis C, Hubbard CS, Dolence EK, Rose JD, Coddington E. Corticosterone suppresses vasotocin-enhanced clasping behavior in male rough-skinned newts by novel mechanisms interfering with V1a receptor availability and receptor-mediated endocytosis. Horm Behav 2015; 69:39-49. [PMID: 25528549 DOI: 10.1016/j.yhbeh.2014.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 11/14/2014] [Accepted: 12/11/2014] [Indexed: 12/17/2022]
Abstract
In rough-skinned newts, Taricha granulosa, exposure to an acute stressor results in the rapid release of corticosterone (CORT), which suppresses the ability of vasotocin (VT) to enhance clasping behavior. CORT also suppresses VT-induced spontaneous activity and sensory responsiveness of clasp-controlling neurons in the rostromedial reticular formation (Rf). The cellular mechanisms underlying this interaction remain unclear. We hypothesized that CORT blocks VT-enhanced clasping by interfering with V1a receptor availability and/or VT-induced endocytosis. We administered a physiologically active fluorescent VT conjugated to Oregon Green (VT-OG) to the fourth ventricle 9 min after an intraperitoneal injection of CORT (0, 10, 40 μg/0.1mL amphibian Ringers). The brains were collected 30 min post-VT-OG, fixed, and imaged with confocal microscopy. CORT diminished the number of endocytosed vesicles, percent area containing VT-OG, sum intensity of VT-OG, and the amount of VT-V1a within each vesicle; indicating that CORT was interfering with V1a receptor availability and VT-V1a receptor-mediated endocytosis. CORT actions were brain location-specific and season-dependent in a manner that is consistent with the natural and context-dependent expression of clasping behavior. Furthermore, the sensitivity of the Rf to CORT was much higher in animals during the breeding season, arguing for ethologically appropriate seasonal variation in CORT's ability to prevent VT-induced endocytosis. Our data are consistent with the time course and interaction effects of CORT and VT on clasping behavior and neurophysiology. CORT interference with VT-induced endocytosis may be a common mechanism employed by hormones across taxa for mediating rapid context- and season-specific behavioral responses.
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Affiliation(s)
- Audrey Davis
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Emily Abraham
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Erin McEvoy
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Sarah Sonnenfeld
- Department of Biology, Willamette University, Salem, OR 97301, USA
| | - Christine Lewis
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Catherine S Hubbard
- Department of Neural & Pain Sciences, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA
| | - E Kurt Dolence
- School of Pharmacy, University of Wyoming, Laramie, WY, USA
| | - James D Rose
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Emma Coddington
- Department of Biology, Willamette University, Salem, OR 97301, USA.
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Pemberton JG, Orr ME, Stafford JL, Chang JP. PI3K signalling in GnRH actions on dispersed goldfish pituitary cells: relationship with PKC-mediated LH and GH release and regulation of long-term effects on secretion and total cellular hormone availability. Gen Comp Endocrinol 2014; 205:268-78. [PMID: 24681225 DOI: 10.1016/j.ygcen.2014.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 03/12/2014] [Indexed: 01/20/2023]
Abstract
Goldfish pituitary cells are exposed to two GnRHs, salmon (s)GnRH and chicken (c)GnRH-II. Phosphoinositide 3-kinase (PI3K) and protein kinase C (PKC) both participate in acute sGnRH- and cGnRH-II-stimulated LH and GH release. Using goldfish pituitary cells, we examined the relationship between PI3K and PKC in acute LH and GH secretion, and PI3K involvement in chronic hormone release and total LH and GH availability. The PI3K inhibitor LY294002 did not affect PKC agonists-induced LH or GH release, and PKC agonists did not alter PI3K p85 phosphorylation, suggesting PKC activation is not upstream of PI3K in acute hormone release. In 2, 6, 12 and 24h treatments, LY294002 did not affect LH release but stimulated total LH availability at 6h. sGnRH stimulatory actions on LH release and total availability at 12 and 24h, and cGnRH-II effects on these parameters at 6h were inhibited by LY294002. LY294002 enhanced basal GH release at 2 and 6h, but reduced total GH at 12 and 24h. Increased GH release was seen following 6, 12 and 24h of sGnRH, and 2, 6 and 24h of cGnRH-II treatment but total GH availability was only elevated by 24h cGnRH-II treatment. Whereas LY294002 inhibited GH release responses to sGnRH at 12h and cGnRH-II at 6h, it attenuated cGnRH-II-elicited, but not sGnRH-induced, effects on total GH. These results indicate that PI3K differentially modulates long-term basal and GnRH-stimulated hormone release, and total hormone availability, in a time-, cell-type-, and GnRH isoform-selective manner.
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Affiliation(s)
- Joshua G Pemberton
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael E Orr
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - James L Stafford
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - John P Chang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Tian X, Kang DS, Benovic JL. β-arrestins and G protein-coupled receptor trafficking. Handb Exp Pharmacol 2014; 219:173-86. [PMID: 24292830 DOI: 10.1007/978-3-642-41199-1_9] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nonvisual arrestins (β-arrestin-1 and β-arrestin-2) are adaptor proteins that function to regulate G protein-coupled receptor (GPCR) signaling and trafficking. β-arrestins are ubiquitously expressed and function to inhibit GPCR/G protein coupling, a process called desensitization, and promote GPCR trafficking and arrestin-mediated signaling. β-arrestin-mediated endocytosis of GPCRs requires the coordinated interaction of β-arrestins with clathrin, adaptor protein 2 (AP2), and phosphoinositides. These interactions are facilitated by a conformational change in β-arrestin that is thought to occur upon binding to a phosphorylated activated GPCR. In this review, we provide an overview of the key interactions involved in β-arrestin-mediated trafficking of GPCRs.
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Affiliation(s)
- Xufan Tian
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 South 10th Street, Philadelphia, PA, 19107, USA
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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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C5L2 is required for C5a-triggered receptor internalization and ERK signaling. Cell Signal 2014; 26:1409-19. [PMID: 24631530 DOI: 10.1016/j.cellsig.2014.02.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 02/24/2014] [Indexed: 12/26/2022]
Abstract
C5L2 is a receptor that binds to C5a and belongs to the family of G protein-coupled receptors, but its role in physiological C5a-mediated responses remains under debate. Here we show that, like the canonical C5a receptor C5aR, C5L2 plays a pro-inflammatory role in a murine model of acute experimental colitis. We demonstrate that C5L2 physically interacts with C5aR and is required for optimal C5a-mediated C5aR internalization and associated ERK activation. Abrogation of C5a-induced receptor internalization by treatment with the dynamin inhibitor dynasore(TM) impaired C5a-induced MEK and ERK signaling. Although the presence of C5aR alone was sufficient to recruit the scaffold protein β-arrestin1 to the cell membrane in response to C5a stimulation, it was inadequate to mediate AP2 recruitment and subsequent C5aR internalization. Expression of C5L2 allowed normal internalization of C5aR in response to C5a stimulation, followed by normal ERK signaling. Thus, our work reveals an essential role for C5L2 in C5a-triggered, AP2-dependent C5aR internalization and downstream ERK signaling.
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Corbi G, Conti V, Russomanno G, Longobardi G, Furgi G, Filippelli A, Ferrara N. Adrenergic signaling and oxidative stress: a role for sirtuins? Front Physiol 2013. [PMID: 24265619 DOI: 10.3389/fphys.2013.00324.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The adrenergic system plays a central role in stress signaling and stress is often associated with increased production of ROS. However, ROS overproduction generates oxidative stress, that occurs in response to several stressors. β-adrenergic signaling is markedly attenuated in conditions such as heart failure, with downregulation and desensitization of the receptors and their uncoupling from adenylyl cyclase. Transgenic activation of β2-adrenoceptor leads to elevation of NADPH oxidase activity, with greater ROS production and p38MAPK phosphorylation. Inhibition of NADPH oxidase or ROS significantly reduced the p38MAPK signaling cascade. Chronic β2-adrenoceptor activation is associated with greater cardiac dilatation and dysfunction, augmented pro-inflammatory and profibrotic signaling, while antioxidant treatment protected hearts against these abnormalities, indicating ROS production to be central to the detrimental signaling of β2-adrenoceptors. It has been demonstrated that sirtuins are involved in modulating the cellular stress response directly by deacetylation of some factors. Sirt1 increases cellular stress resistance, by an increased insulin sensitivity, a decreased circulating free fatty acids and insulin-like growth factor (IGF-1), an increased activity of AMPK, increased activity of PGC-1a, and increased mitochondrial number. Sirt1 acts by involving signaling molecules such P-I-3-kinase-Akt, MAPK and p38-MAPK-β. βAR stimulation antagonizes the protective effect of the AKT pathway through inhibiting induction of Hif-1α and Sirt1 genes, key elements in cell survival. More studies are needed to better clarify the involvement of sirtuins in the β-adrenergic response and, overall, to better define the mechanisms by which tools such as exercise training are able to counteract the oxidative stress, by both activation of sirtuins and inhibition of GRK2 in many cardiovascular conditions and can be used to prevent or treat diseases such as heart failure.
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Affiliation(s)
- Graziamaria Corbi
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
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Penela P, Nogués L, Mayor F. Role of G protein-coupled receptor kinases in cell migration. Curr Opin Cell Biol 2013; 27:10-7. [PMID: 24680425 DOI: 10.1016/j.ceb.2013.10.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 01/09/2023]
Abstract
G protein-coupled receptor kinases (GRKs) are emerging as important integrative nodes in cell migration processes. Recent evidence links GRKs (particularly the GRK2 isoform) to the complex modulation of diverse aspects of cell motility. In addition to its well-established role in the desensitization of G protein-coupled receptors involved in chemotaxis, GRK2 can play an effector role in the organization of actin and microtubule networks and in adhesion dynamics, by means of novel substrates and transient interacting partners, such as the GIT1 scaffold or the cytoplasmic α-tubulin deacetylase histone deacetylase 6 (HDAC6). The overall effect of altering GRK levels or activity on chemotaxis would depend on how such different roles are integrated in a given cell type and physiological context, and may have relevant implications in inflammatory diseases or cancer progression.
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Affiliation(s)
- Petronila Penela
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Universidad Autónoma de Madrid, 28049 Madrid, Spain; Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
| | - Laura Nogués
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Universidad Autónoma de Madrid, 28049 Madrid, Spain; Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
| | - Federico Mayor
- Departamento de Biología Molecular and Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas - Universidad Autónoma de Madrid), Universidad Autónoma de Madrid, 28049 Madrid, Spain; Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain.
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Proteomic identification of dengue virus binding proteins in Aedes aegypti mosquitoes and Aedes albopictus cells. BIOMED RESEARCH INTERNATIONAL 2013; 2013:875958. [PMID: 24324976 PMCID: PMC3842078 DOI: 10.1155/2013/875958] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 09/19/2013] [Accepted: 09/25/2013] [Indexed: 12/22/2022]
Abstract
The main vector of dengue in America is the mosquito Aedes aegypti, which is infected by dengue virus (DENV) through receptors of midgut epithelial cells. The envelope protein (E) of dengue virus binds to receptors present on the host cells through its domain III that has been primarily recognized to bind cell receptors. In order to identify potential receptors, proteins from mosquito midgut tissue and C6/36 cells were purified by affinity using columns with the recombinant E protein domain III (rE-DIII) or DENV particles bound covalently to Sepharose 4B to compare and evaluate their performance to bind proteins including putative receptors from female mosquitoes of Ae. aegypti. To determine their identity mass spectrometric analysis of purified proteins separated by polyacrylamide gel electrophoresis was performed. Our results indicate that both viral particles and rE-DIII bound proteins with the same apparent molecular weights of 57 and 67 kDa. In addition, viral particles bound high molecular weight proteins. Purified proteins identified were enolase, beta-adrenergic receptor kinase (beta-ARK), translation elongation factor EF-1 alpha/Tu, and cadherin.
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Corbi G, Conti V, Russomanno G, Longobardi G, Furgi G, Filippelli A, Ferrara N. Adrenergic signaling and oxidative stress: a role for sirtuins? Front Physiol 2013; 4:324. [PMID: 24265619 PMCID: PMC3820966 DOI: 10.3389/fphys.2013.00324] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 10/18/2013] [Indexed: 12/17/2022] Open
Abstract
The adrenergic system plays a central role in stress signaling and stress is often associated with increased production of ROS. However, ROS overproduction generates oxidative stress, that occurs in response to several stressors. β-adrenergic signaling is markedly attenuated in conditions such as heart failure, with downregulation and desensitization of the receptors and their uncoupling from adenylyl cyclase. Transgenic activation of β2-adrenoceptor leads to elevation of NADPH oxidase activity, with greater ROS production and p38MAPK phosphorylation. Inhibition of NADPH oxidase or ROS significantly reduced the p38MAPK signaling cascade. Chronic β2-adrenoceptor activation is associated with greater cardiac dilatation and dysfunction, augmented pro-inflammatory and profibrotic signaling, while antioxidant treatment protected hearts against these abnormalities, indicating ROS production to be central to the detrimental signaling of β2-adrenoceptors. It has been demonstrated that sirtuins are involved in modulating the cellular stress response directly by deacetylation of some factors. Sirt1 increases cellular stress resistance, by an increased insulin sensitivity, a decreased circulating free fatty acids and insulin-like growth factor (IGF-1), an increased activity of AMPK, increased activity of PGC-1a, and increased mitochondrial number. Sirt1 acts by involving signaling molecules such P-I-3-kinase-Akt, MAPK and p38-MAPK-β. βAR stimulation antagonizes the protective effect of the AKT pathway through inhibiting induction of Hif-1α and Sirt1 genes, key elements in cell survival. More studies are needed to better clarify the involvement of sirtuins in the β-adrenergic response and, overall, to better define the mechanisms by which tools such as exercise training are able to counteract the oxidative stress, by both activation of sirtuins and inhibition of GRK2 in many cardiovascular conditions and can be used to prevent or treat diseases such as heart failure.
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Affiliation(s)
- Graziamaria Corbi
- Department of Medicine and Health Sciences, University of Molise Campobasso, Italy
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46
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Molecular determinants of PI3Kγ-mediated activation downstream of G-protein-coupled receptors (GPCRs). Proc Natl Acad Sci U S A 2013; 110:18862-7. [PMID: 24190998 DOI: 10.1073/pnas.1304801110] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Phosphoinositide 3-kinase gamma (PI3Kγ) has profound roles downstream of G-protein-coupled receptors in inflammation, cardiac function, and tumor progression. To gain insight into how the enzyme's activity is shaped by association with its p101 adaptor subunit, lipid membranes, and Gβγ heterodimers, we mapped these regulatory interactions using hydrogen-deuterium exchange mass spectrometry. We identify residues in both the p110γ and p101 subunits that contribute critical interactions with Gβγ heterodimers, leading to PI3Kγ activation. Mutating Gβγ-interaction sites of either p110γ or p101 ablates G-protein-coupled receptor-mediated signaling to p110γ/p101 in cells and severely affects chemotaxis and cell transformation induced by PI3Kγ overexpression. Hydrogen-deuterium exchange mass spectrometry shows that association with the p101 regulatory subunit causes substantial protection of the RBD-C2 linker as well as the helical domain of p110γ. Lipid interaction massively exposes that same helical site, which is then stabilized by Gβγ. Membrane-elicited conformational change of the helical domain could help prepare the enzyme for Gβγ binding. Our studies and others identify the helical domain of the class I PI3Ks as a hub for diverse regulatory interactions that include the p101, p87 (also known as p84), and p85 adaptor subunits; Rab5 and Gβγ heterodimers; and the β-adrenergic receptor kinase.
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Abstract
PI3Ks are signaling enzymes engaged by different types of membrane receptors and activated in cardiovascular diseases such as hypertension, atherosclerosis, thrombosis and heart failure. Studies performed on genetically modified animals have provided proof-of-concept that general or isoform-specific blockade of these enzymes can modify disease development and progression. Hence, therapeutic inhibition of PI3Ks with novel pharmacological compounds constitutes a promising area of drug development. In particular, inhibitors of PI3Ks have the potential to reduce blood pressure, restrain the development of atherosclerosis and/or stabilize atherosclerotic plaques, blunt platelet aggregation, prevent left ventricular remodeling and preserve myocardial contractility in heart failure. This review summarizes the rationale of PI3K inhibition in the most prevalent cardiovascular diseases, and the available data on the therapeutic effects of PI3K inhibitors in their preclinical models. Implications for future drug development and human therapy are also discussed.
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Roux J, McNicholas CM, Carles M, Goolaerts A, Houseman BT, Dickinson DA, Iles KE, Ware LB, Matthay MA, Pittet JF. IL-8 inhibits cAMP-stimulated alveolar epithelial fluid transport via a GRK2/PI3K-dependent mechanism. FASEB J 2013; 27:1095-106. [PMID: 23221335 PMCID: PMC3574281 DOI: 10.1096/fj.12-219295] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/13/2012] [Indexed: 12/27/2022]
Abstract
Patients with acute lung injury (ALI) who retain maximal alveolar fluid clearance (AFC) have better clinical outcomes. Experimental and small clinical studies have shown that β2-adrenergic receptor (β2AR) agonists enhance AFC via a cAMP-dependent mechanism. However, two multicenter phase 3 clinical trials failed to show that β2AR agonists provide a survival advantage in patients with ALI. We hypothesized that IL-8, an important mediator of ALI, directly antagonizes the alveolar epithelial response to β2AR agonists. Short-circuit current and whole-cell patch-clamping experiments revealed that IL-8 or its rat analog CINC-1 decreases by 50% β2AR agonist-stimulated vectorial Cl(-) and net fluid transport across rat and human alveolar epithelial type II cells via a reduction in the cystic fibrosis transmembrane conductance regulator activity and biosynthesis. This reduction was mediated by heterologous β2AR desensitization and down-regulation (50%) via the G-protein-coupled receptor kinase 2 (GRK2)/PI3K signaling pathway. Inhibition of CINC-1 restored β2AR agonist-stimulated AFC in an experimental model of ALI in rats. Finally, consistent with the experimental results, high pulmonary edema fluid levels of IL-8 (>4000 pg/ml) were associated with impaired AFC in patients with ALI. These results demonstrate a novel role for IL-8 in inhibiting β2AR agonist-stimulated alveolar epithelial fluid transport via GRK2/PI3K-dependent mechanisms.-Roux, J., McNicholas, C. M., Carles, M., Goolaerts, A., Houseman, B. T., Dickinson, D. A., Iles, K. E., Ware, L. B., Matthay, M. A., Pittet, J.-F. IL-8 inhibits cAMP-stimulated alveolar epithelial fluid transport via a GRK2/PI3K-dependent mechanism.
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Affiliation(s)
| | | | | | | | - Benjamin T. Houseman
- Department of Anesthesia and Perioperative Care
- Department of Cellular Pharmacology, and
| | - Dale A. Dickinson
- Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA; and
| | | | - Lorraine B. Ware
- Department of Medicine, and
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee, USA
| | - Michael A. Matthay
- Cardiovascular Research Institute, University of California, San Francisco, California, USA
| | - Jean-François Pittet
- Cardiovascular Research Institute, University of California, San Francisco, California, USA
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Rossios C, To Y, Osoata G, Ito M, Barnes PJ, Ito K. Corticosteroid insensitivity is reversed by formoterol via phosphoinositide-3-kinase inhibition. Br J Pharmacol 2013; 167:775-86. [PMID: 22251095 DOI: 10.1111/j.1476-5381.2012.01864.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Patients with chronic obstructive pulmonary disease (COPD) show a poor response to corticosteroids, which has been linked to oxidative stress. Here we show that the long-acting β(2) -agonist formoterol (FM) reversed corticosteroid insensitivity under oxidative stress via inhibition of phosphoinositide-3-kinase (PI3K) signalling. EXPERIMENTAL APPROACH Responsiveness to corticosteroids dexamethasone (Dex), budesonide (Bud) and fluticasone propionate (FP) was determined, as IC(50) values on TNF-α-induced interleukin 8 release, in U937 monocytic cell line treated with hydrogen peroxide (H(2) O(2) ) or peripheral blood mononuclear cells (PBMCs) from patients with COPD or severe asthma. KEY RESULTS PBMCs from severe asthma and COPD were less sensitive to Dex compared with those from healthy subjects. Both FM (10(-9) M) and salmeterol (SM, 10(-8) M) reversed Dex insensitivity in severe asthma, but only FM restored Dex sensitivity in COPD. Although H(2) O(2) exposure decreased steroid sensitivity in U937 cells, FM restored responsiveness to Bud and FP while the effects of SM were weaker. Additionally, FM, but not SM, partially inhibited H(2) O(2) -induced PI3Kδ-dependent (PKB) phosphorylation. H(2) O(2) decreased SM-induced cAMP production in U937 cells, but did not significantly affect the response to FM. The reduction of SM effects by H(2) O(2) was reversed by pretreatment with LY294002, a PI3K inhibitor, or IC87114, a PI3Kδ inhibitor. CONCLUSION AND IMPLICATIONS FM reversed oxidative stress-induced corticosteroid insensitivity and decreased β(2) adrenoceptor-dependent cAMP production via inhibition of PI3Kδ signalling. FM will be more effective than SM, when combined with corticosteroids, for the treatment of respiratory diseases under conditions of high oxidative stress, such as in COPD.
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Affiliation(s)
- C Rossios
- Airway Disease Section, NHLI, Imperial College, London, UK
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Mohan ML, Jha BK, Gupta MK, Vasudevan NT, Martelli EE, Mosinski JD, Naga Prasad SV. Phosphoinositide 3-kinase γ inhibits cardiac GSK-3 independently of Akt. Sci Signal 2013; 6:ra4. [PMID: 23354687 DOI: 10.1126/scisignal.2003308] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Activation of cardiac phosphoinositide 3-kinase α (PI3Kα) by growth factors, such as insulin, or activation of PI3Kγ downstream of heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors stimulates the activity of the kinase Akt, which phosphorylates and inhibits glycogen synthase kinase-3 (GSK-3). We found that PI3Kγ inhibited GSK-3 independently of the insulin-PI3Kα-Akt axis. Although insulin treatment activated Akt in PI3Kγ knockout mice, phosphorylation of GSK-3 was decreased compared to control mice. GSK-3 is activated when dephosphorylated by the protein phosphatase 2A (PP2A), which is activated when methylated by the PP2A methyltransferase PPMT-1. PI3Kγ knockout mice showed increased activity of PPMT-1 and PP2A and enhanced nuclear export of the GSK-3 substrate NFATc3. GSK-3 inhibits cardiac hypertrophy, and the hearts of PI3Kγ knockout mice were smaller compared to those of wild-type mice. Cardiac overexpression of a catalytically inactive PI3Kγ (PI3Kγ(inact)) transgene in PI3Kγ knockout mice reduced the activities of PPMT-1 and PP2A and increased phosphorylation of GSK-3. Furthermore, PI3Kγ knockout mice expressing the PI3Kγ(inact) transgene had larger hearts than wild-type or PI3Kγ knockout mice. Our studies show that a kinase-independent function of PI3Kγ could directly inhibit GSK-3 function by preventing the PP2A-PPMT-1 interaction and that this inhibition of GSK-3 was independent of Akt.
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Affiliation(s)
- Maradumane L Mohan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
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