1
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Mastos C, Xu X, Keen AC, Halls ML. Signalling of Adrenoceptors: Canonical Pathways and New Paradigms. Handb Exp Pharmacol 2024. [PMID: 38227198 DOI: 10.1007/164_2023_704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The concept of G protein-coupled receptors initially arose from studies of the β-adrenoceptor, adenylyl cyclase, and cAMP signalling pathway. Since then both canonical G protein-coupled receptor signalling pathways and emerging paradigms in receptor signalling have been defined by experiments focused on adrenoceptors. Here, we discuss the evidence for G protein coupling specificity of the nine adrenoceptor subtypes. We summarise the ability of each of the adrenoceptors to activate proximal signalling mediators including cAMP, calcium, mitogen-activated protein kinases, and protein kinase C pathways. Finally, we highlight the importance of precise spatial and temporal control of adrenoceptor signalling that is controlled by the localisation of receptors at intracellular membranes and in larger protein complexes.
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Affiliation(s)
- Chantel Mastos
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Alastair C Keen
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
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2
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Jovanovic A, Xu B, Zhu C, Ren D, Wang H, Krause-Hauch M, Abel ED, Li J, Xiang YK. Characterizing Adrenergic Regulation of Glucose Transporter 4-Mediated Glucose Uptake and Metabolism in the Heart. JACC Basic Transl Sci 2023. [DOI: 10.1016/j.jacbts.2022.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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3
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Paulussen F, Kulkarni CP, Stolz F, Lescrinier E, De Graeve S, Lambin S, Marchand A, Chaltin P, In't Veld P, Mebis J, Tavernier J, Van Dijck P, Luyten W, Thevelein JM. The β2-adrenergic receptor in the apical membrane of intestinal enterocytes senses sugars to stimulate glucose uptake from the gut. Front Cell Dev Biol 2023; 10:1041930. [PMID: 36699012 PMCID: PMC9869975 DOI: 10.3389/fcell.2022.1041930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
The presence of sugar in the gut causes induction of SGLT1, the sodium/glucose cotransporter in intestinal epithelial cells (enterocytes), and this is accompanied by stimulation of sugar absorption. Sugar sensing was suggested to involve a G-protein coupled receptor and cAMP - protein kinase A signalling, but the sugar receptor has remained unknown. We show strong expression and co-localization with SGLT1 of the β2-adrenergic receptor (β 2-AR) at the enterocyte apical membrane and reveal its role in stimulating glucose uptake from the gut by the sodium/glucose-linked transporter, SGLT1. Upon heterologous expression in different reporter systems, the β 2-AR responds to multiple sugars in the mM range, consistent with estimated gut sugar levels after a meal. Most adrenergic receptor antagonists inhibit sugar signaling, while some differentially inhibit epinephrine and sugar responses. However, sugars did not inhibit binding of I125-cyanopindolol, a β 2-AR antagonist, to the ligand-binding site in cell-free membrane preparations. This suggests different but interdependent binding sites. Glucose uptake into everted sacs from rat intestine was stimulated by epinephrine and sugars in a β 2-AR-dependent manner. STD-NMR confirmed direct physical binding of glucose to the β 2-AR. Oral administration of glucose with a non-bioavailable β 2-AR antagonist lowered the subsequent increase in blood glucose levels, confirming a role for enterocyte apical β 2-ARs in stimulating gut glucose uptake, and suggesting enterocyte β 2-AR as novel drug target in diabetic and obese patients. Future work will have to reveal how glucose sensing by enterocytes and neuroendocrine cells is connected, and whether β 2-ARs mediate glucose sensing also in other tissues.
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Affiliation(s)
- Frederik Paulussen
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Chetan P. Kulkarni
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,3Functional Genomics and Proteomics Research Unit, Department of Biology, KU Leuven, Leuven, Belgium
| | - Frank Stolz
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Eveline Lescrinier
- 4Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Stijn De Graeve
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Suzan Lambin
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | | | | | - Peter In't Veld
- 6Department of Pathology, Free University of Brussels, Brussels, Belgium
| | - Joseph Mebis
- 7Department of Pathology, KU Leuven, Flanders, Belgium
| | - Jan Tavernier
- 8Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium,9Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Patrick Van Dijck
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Walter Luyten
- 3Functional Genomics and Proteomics Research Unit, Department of Biology, KU Leuven, Leuven, Belgium
| | - Johan M. Thevelein
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium,10NovelYeast bv, Bio-Incubator BIO4, Gaston Geenslaan 3, Leuven-Heverlee,, Belgium,*Correspondence: Johan M. Thevelein,
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4
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Meister J, Bone DBJ, Knudsen JR, Barella LF, Velenosi TJ, Akhmedov D, Lee RJ, Cohen AH, Gavrilova O, Cui Y, Karsenty G, Chen M, Weinstein LS, Kleinert M, Berdeaux R, Jensen TE, Richter EA, Wess J. Clenbuterol exerts antidiabetic activity through metabolic reprogramming of skeletal muscle cells. Nat Commun 2022; 13:22. [PMID: 35013148 PMCID: PMC8748640 DOI: 10.1038/s41467-021-27540-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 11/24/2021] [Indexed: 12/14/2022] Open
Abstract
Activation of the sympathetic nervous system causes pronounced metabolic changes that are mediated by multiple adrenergic receptor subtypes. Systemic treatment with β2-adrenergic receptor agonists results in multiple beneficial metabolic effects, including improved glucose homeostasis. To elucidate the underlying cellular and molecular mechanisms, we chronically treated wild-type mice and several newly developed mutant mouse strains with clenbuterol, a selective β2-adrenergic receptor agonist. Clenbuterol administration caused pronounced improvements in glucose homeostasis and prevented the metabolic deficits in mouse models of β-cell dysfunction and insulin resistance. Studies with skeletal muscle-specific mutant mice demonstrated that these metabolic improvements required activation of skeletal muscle β2-adrenergic receptors and the stimulatory G protein, Gs. Unbiased transcriptomic and metabolomic analyses showed that chronic β2-adrenergic receptor stimulation caused metabolic reprogramming of skeletal muscle characterized by enhanced glucose utilization. These findings strongly suggest that agents targeting skeletal muscle metabolism by modulating β2-adrenergic receptor-dependent signaling pathways may prove beneficial as antidiabetic drugs.
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Affiliation(s)
- Jaroslawna Meister
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| | - Derek B J Bone
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Jonas R Knudsen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Luiz F Barella
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Thomas J Velenosi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Dmitry Akhmedov
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Regina J Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Amanda H Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Oksana Gavrilova
- Mouse Metabolism Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Gerard Karsenty
- Departments of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Maximilian Kleinert
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
- Muscle Physiology and Metabolism Group, German Institute of Human Nutrition, Potsdam-Rehbrücke, Nuthetal, Germany
| | - Rebecca Berdeaux
- Departments of Integrative Biology and Pharmacology, Houston Medical School, Houston, TX, 77030, USA
| | - Thomas E Jensen
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Erik A Richter
- Departments of Nutrition, Exercise and Sports, University of Copenhagen, København, Denmark
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
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5
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In vivo metabolic effects after acute activation of skeletal muscle G s signaling. Mol Metab 2021; 55:101415. [PMID: 34883278 PMCID: PMC8728399 DOI: 10.1016/j.molmet.2021.101415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 11/21/2021] [Accepted: 12/02/2021] [Indexed: 11/21/2022] Open
Abstract
Objective The goal of this study was to determine the glucometabolic effects of acute activation of Gs signaling in skeletal muscle (SKM) in vivo and its contribution to whole-body glucose homeostasis. Methods To address this question, we studied mice that express a Gs-coupled designer G protein-coupled receptor (Gs-DREADD or GsD) selectively in skeletal muscle. We also identified two Gs-coupled GPCRs that are endogenously expressed by SKM at relatively high levels (β2-adrenergic receptor and CRF2 receptor) and studied the acute metabolic effects of activating these receptors in vivo by highly selective agonists (clenbuterol and urocortin 2 (UCN2), respectively). Results Acute stimulation of GsD signaling in SKM impaired glucose tolerance in lean and obese mice by decreasing glucose uptake selectively into SKM. The acute metabolic effects following agonist activation of β2-adrenergic and, potentially, CRF2 receptors appear primarily mediated by altered insulin release. Clenbuterol injection improved glucose tolerance by increasing insulin secretion in lean mice. In SKM, clenbuterol stimulated glycogen breakdown. UCN2 injection resulted in decreased glucose tolerance associated with lower plasma insulin levels. The acute metabolic effects of UCN2 were not mediated by SKM Gs signaling. Conclusions Selective activation of Gs signaling in SKM causes an acute increase in blood glucose levels. However, acute in vivo stimulation of endogenous Gs-coupled receptors enriched in SKM has only a limited impact on whole-body glucose homeostasis, most likely due to the fact that these receptors are also expressed by pancreatic islets where they modulate insulin release. A novel mouse model allowed us to study the in vivo metabolic effects of acute activation of Gs signaling in skeletal muscle (SKM). Acute stimulation of this pathway resulted in impaired glucose tolerance in lean and obese mice due to decreased glucose uptake by SKM. Acute treatment of mice with selective β2-adrenergic and CRF2 receptor agonists (both receptors couple to Gs and are enriched in SKM) resulted in complex in vivo metabolic outcomes, primarily due to altered insulin release. Our study provides an excellent example of how different tissue expression patterns of receptors can affect the acute effects of GPCR agonists on whole-body glucose homeostasis Our findings also highlight the importance of studying both acute and chronic effects of GPCR agonist treatment to properly assess translationally relevant metabolic outcomes.
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6
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van Beek SMM, Kalinovich A, Schaart G, Bengtsson T, Hoeks J. Prolonged β 2-adrenergic agonist treatment improves glucose homeostasis in diet-induced obese UCP1 -/- mice. Am J Physiol Endocrinol Metab 2021; 320:E619-E628. [PMID: 33522400 DOI: 10.1152/ajpendo.00324.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Prolonged supplementation with the β2-agonist clenbuterol improves glucose homeostasis in diabetic rodents, likely via β2-adrenoceptor (β2-AR)-mediated effects in the skeletal muscle and liver. However, since rodents have, in contrast to-especially diabetic-humans, substantial quantities of brown adipose tissue (BAT) and clenbuterol has affinity to β1- and β3-ARs, the contribution of BAT to these improvements is unclear. Therefore, we investigated clenbuterol-mediated improvements in glucose homeostasis in uncoupling protein 1-deficient (UCP1-/-) mice, lacking thermogenic BAT, versus wild-type (WT) mice. Anesthetized WT and UCP1-/- C57Bl/6 mice were injected with saline or clenbuterol and whole body oxygen consumption was measured. Furthermore, male WT and UCP1-/- C57Bl/6 mice were subjected to 17-wk of chow feeding, high-fat feeding, or high-fat feeding with clenbuterol treatment between weeks 13 and 17. Body composition was measured weekly with MRI. Oral glucose tolerance and insulin tolerance tests were performed in week 15 and 17, respectively. Clenbuterol increased oxygen consumption approximately twofold in WT mice. This increase was blunted in UCP1-/- mice, indicating clenbuterol-mediated activation of BAT thermogenesis. High-fat feeding induced diabetogenic phenotypes in both genotypes. However, low-dose clenbuterol treatment for 2 wk significantly reduced fasting blood glucose by 12.9% in WT and 14.8% in UCP1-/- mice. Clenbuterol treatment improved glucose and insulin tolerance in both genotypes compared with HFD controls and normalized to chow-fed control mice independent of body mass and composition alterations. Clenbuterol improved whole body glucose homeostasis independent of UCP1. Given the low human abundancy of BAT, β2-AR agonist treatment provides a potential novel route for glucose disposal in diabetic humans.NEW & NOTEWORTHY Improvements in whole body glucose homeostasis of rodents upon prolonged β2-adrenergic agonist supplementation could potentially be attributed to UCP1-mediated BAT thermogenesis. Indeed, we show that acute injection with the β2-AR agonist clenbuterol induces BAT activation in mice. However, we also demonstrate that prolonged clenbuterol supplementation robustly improves whole body glucose and insulin tolerance in a similar way in both DIO WT and UCP1-/- mice, indicating that β2-AR agonist supplementation improves whole body glucose homeostasis independent of UCP1-mediated BAT thermogenesis.
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Affiliation(s)
- Sten M M van Beek
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Anastasia Kalinovich
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Gert Schaart
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Joris Hoeks
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands
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7
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Civciristov S, Halls ML. Signalling in response to sub-picomolar concentrations of active compounds: Pushing the boundaries of GPCR sensitivity. Br J Pharmacol 2019; 176:2382-2401. [PMID: 30801691 DOI: 10.1111/bph.14636] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/04/2019] [Accepted: 02/11/2019] [Indexed: 12/22/2022] Open
Abstract
There is evidence for ultra-sensitive responses to active compounds at concentrations below picomolar levels by proteins and receptors found in species ranging from bacteria to mammals. We have recently shown that such ultra-sensitivity is also demonstrated by a wide range of prototypical GPCRs, and we have determined the molecular mechanisms behind these responses for three family A GPCRs: the relaxin receptor, RXFP1; the β2 -adrenoceptor; and the M3 muscarinic ACh receptor. Interestingly, there are reports of similar ultra-sensitivity by more than 15 human GPCR families, in addition to other human receptors and channels. These occur through a diverse range of signalling pathways and produce modulation of important physiological processes, including neuronal transmission, chemotaxis, gene transcription, protein/ion uptake and secretion, muscle contraction and relaxation, and phagocytosis. Here, we summarise the accumulating evidence of ultra-sensitive receptor signalling to show that this is a common, though currently underappreciated, property of GPCRs. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Srgjan Civciristov
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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8
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Mukaida S, Sato M, Öberg AI, Dehvari N, Olsen JM, Kocan M, Halls ML, Merlin J, Sandström AL, Csikasz RI, Evans BA, Summers RJ, Hutchinson DS, Bengtsson T. BRL37344 stimulates GLUT4 translocation and glucose uptake in skeletal muscle via β 2-adrenoceptors without causing classical receptor desensitization. Am J Physiol Regul Integr Comp Physiol 2019; 316:R666-R677. [PMID: 30892909 DOI: 10.1152/ajpregu.00285.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The type 2 diabetes epidemic makes it important to find insulin-independent ways to improve glucose homeostasis. This study examines the mechanisms activated by a dual β2-/β3-adrenoceptor agonist, BRL37344, to increase glucose uptake in skeletal muscle and its effects on glucose homeostasis in vivo. We measured the effect of BRL37344 on glucose uptake, glucose transporter 4 (GLUT4) translocation, cAMP levels, β2-adrenoceptor desensitization, β-arrestin recruitment, Akt, AMPK, and mammalian target of rapamycin (mTOR) phosphorylation using L6 skeletal muscle cells as a model. We further tested the ability of BRL37344 to modulate skeletal muscle glucose metabolism in animal models (glucose tolerance tests and in vivo and ex vivo skeletal muscle glucose uptake). In L6 cells, BRL37344 increased GLUT4 translocation and glucose uptake only by activation of β2-adrenoceptors, with a similar potency and efficacy to that of the nonselective β-adrenoceptor agonist isoprenaline, despite being a partial agonist with respect to cAMP generation. GLUT4 translocation occurred independently of Akt and AMPK phosphorylation but was dependent on mTORC2. Furthermore, in contrast to isoprenaline, BRL37344 did not promote agonist-mediated desensitization and failed to recruit β-arrestin1/2 to the β2-adrenoceptor. In conclusion, BRL37344 improved glucose tolerance and increased glucose uptake into skeletal muscle in vivo and ex vivo through a β2-adrenoceptor-mediated mechanism independently of Akt. BRL37344 was a partial agonist with respect to cAMP, but a full agonist for glucose uptake, and importantly did not cause classical receptor desensitization or internalization of the receptor.
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Affiliation(s)
- Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Anette I Öberg
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
| | - Nodi Dehvari
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
| | - Jessica M Olsen
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
| | - Martina Kocan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Michelle Louise Halls
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Anna L Sandström
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
| | - Robert I Csikasz
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
| | - Bronwyn Anne Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia
| | - Roger James Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia.,Department of Pharmacology, Monash University , Clayton, Victoria , Australia
| | - Dana Sabine Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria , Australia.,Department of Pharmacology, Monash University , Clayton, Victoria , Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, The Arrhenius Laboratories F3, Stockholm University , Stockholm , Sweden
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9
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Civciristov S, Ellisdon AM, Suderman R, Pon CK, Evans BA, Kleifeld O, Charlton SJ, Hlavacek WS, Canals M, Halls ML. Preassembled GPCR signaling complexes mediate distinct cellular responses to ultralow ligand concentrations. Sci Signal 2018; 11:11/551/eaan1188. [PMID: 30301787 DOI: 10.1126/scisignal.aan1188] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest class of cell surface signaling proteins, participate in nearly all physiological processes, and are the targets of 30% of marketed drugs. Typically, nanomolar to micromolar concentrations of ligand are used to activate GPCRs in experimental systems. We detected GPCR responses to a wide range of ligand concentrations, from attomolar to millimolar, by measuring GPCR-stimulated production of cyclic adenosine monophosphate (cAMP) with high spatial and temporal resolution. Mathematical modeling showed that femtomolar concentrations of ligand activated, on average, 40% of the cells in a population provided that a cell was activated by one to two binding events. Furthermore, activation of the endogenous β2-adrenergic receptor (β2AR) and muscarinic acetylcholine M3 receptor (M3R) by femtomolar concentrations of ligand in cell lines and human cardiac fibroblasts caused sustained increases in nuclear translocation of extracellular signal-regulated kinase (ERK) and cytosolic protein kinase C (PKC) activity, respectively. These responses were spatially and temporally distinct from those that occurred in response to higher concentrations of ligand and resulted in a distinct cellular proteomic profile. This highly sensitive signaling depended on the GPCRs forming preassembled, higher-order signaling complexes at the plasma membrane. Recognizing that GPCRs respond to ultralow concentrations of neurotransmitters and hormones challenges established paradigms of drug action and provides a previously unappreciated aspect of GPCR activation that is quite distinct from that typically observed with higher ligand concentrations.
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Affiliation(s)
- Srgjan Civciristov
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew M Ellisdon
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Ryan Suderman
- Theoretical Biology and Biophysics Group, Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Cindy K Pon
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Oded Kleifeld
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia.,Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 3200003, Israel
| | - Steven J Charlton
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.,Excellerate Bioscience Ltd, MediCity, Nottingham NG90 6BH, UK
| | - William S Hlavacek
- Theoretical Biology and Biophysics Group, Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - Meritxell Canals
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
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10
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Santulli G, Iaccarino G. Adrenergic signaling in heart failure and cardiovascular aging. Maturitas 2016; 93:65-72. [PMID: 27062709 PMCID: PMC5036981 DOI: 10.1016/j.maturitas.2016.03.022] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 03/23/2016] [Accepted: 03/25/2016] [Indexed: 12/15/2022]
Abstract
Both cardiovascular disease and aging are associated with changes in the sympathetic nervous system. Indeed, mounting evidence indicates that adrenergic receptors are functionally involved in numerous processes underlying both aging and cardiovascular disorders, in particular heart failure. This article will review the pathophysiological role of the sympathetic nervous system in heart failure and cardiovascular aging.
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Affiliation(s)
- Gaetano Santulli
- College of Physicians & Surgeons, Columbia University Medical Center, New York, NY, USA.
| | - Guido Iaccarino
- Division of Internal Medicine, Department of Medicine and Surgery, University of Salerno, Italy.
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11
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Michel MC, Korstanje C. β3-Adrenoceptor agonists for overactive bladder syndrome: Role of translational pharmacology in a repositioning clinical drug development project. Pharmacol Ther 2016; 159:66-82. [PMID: 26808167 DOI: 10.1016/j.pharmthera.2016.01.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
β3-Adrenoceptor agonists were originally considered as a promising drug class for the treatment of obesity and/or type 2 diabetes. When these development efforts failed, they were repositioned for the treatment of the overactive bladder syndrome. Based on the example of the β3-adrenoceptor agonist mirabegron, but also taking into consideration evidence obtained with ritobegron and solabegron, we discuss challenges facing a translational pharmacology program accompanying clinical drug development for a first-in-class molecule. Challenges included generic ones such as ligand selectivity, species differences and drug target gene polymorphisms. Challenges that are more specific included changing concepts of the underlying pathophysiology of the target condition while clinical development was under way; moreover, a paucity of public domain tools for the study of the drug target and aspects of receptor agonists as drugs had to be addressed. Nonetheless, a successful first-in-class launch was accomplished. Looking back at this translational pharmacology program, we conclude that a specifically tailored and highly flexible approach is required. However, several of the lessons learned may also be applicable to translational pharmacology programs in other indications.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
| | - Cees Korstanje
- Department of Drug Discovery Science & Management-Europe, Astellas Pharma Europe R&D, Leiden, The Netherlands
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12
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Sato M, Dehvari N, Oberg AI, Dallner OS, Sandström AL, Olsen JM, Csikasz RI, Summers RJ, Hutchinson DS, Bengtsson T. Improving type 2 diabetes through a distinct adrenergic signaling pathway involving mTORC2 that mediates glucose uptake in skeletal muscle. Diabetes 2014; 63:4115-29. [PMID: 25008179 DOI: 10.2337/db13-1860] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is an increasing worldwide epidemic of type 2 diabetes that poses major health problems. We have identified a novel physiological system that increases glucose uptake in skeletal muscle but not in white adipocytes. Activation of this system improves glucose tolerance in Goto-Kakizaki rats or mice fed a high-fat diet, which are established models for type 2 diabetes. The pathway involves activation of β2-adrenoceptors that increase cAMP levels and activate cAMP-dependent protein kinase, which phosphorylates mammalian target of rapamycin complex 2 (mTORC2) at S2481. The active mTORC2 causes translocation of GLUT4 to the plasma membrane and glucose uptake without the involvement of Akt or AS160. Stimulation of glucose uptake into skeletal muscle after activation of the sympathetic nervous system is likely to be of high physiological relevance because mTORC2 activation was observed at the cellular, tissue, and whole-animal level in rodent and human systems. This signaling pathway provides new opportunities for the treatment of type 2 diabetes.
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MESH Headings
- Animals
- Blood Glucose/metabolism
- Cells, Cultured
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Diabetes Mellitus, Experimental/etiology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 2/etiology
- Diabetes Mellitus, Type 2/metabolism
- Diet, High-Fat/adverse effects
- Glucose Tolerance Test
- Glucose Transporter Type 4/metabolism
- Mechanistic Target of Rapamycin Complex 2
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Multiprotein Complexes/metabolism
- Muscle, Skeletal/metabolism
- Phosphorylation
- Proto-Oncogene Proteins c-akt/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction
- TOR Serine-Threonine Kinases/metabolism
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Affiliation(s)
- Masaaki Sato
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden Department of Pharmacology, Monash University, Clayton, Victoria, Australia Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Nodi Dehvari
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Anette I Oberg
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Olof S Dallner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden Laboratory of Molecular Genetics, Howard Hughes Medical Institute, The Rockefeller University, New York, NY
| | - Anna L Sandström
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Jessica M Olsen
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Robert I Csikasz
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Roger J Summers
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dana S Hutchinson
- Department of Pharmacology, Monash University, Clayton, Victoria, Australia Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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13
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Ngala RA, Zaibi MS, Langlands K, Stocker CJ, Arch JRS, Cawthorne MA. Stimulation of glucose uptake in murine soleus muscle and adipocytes by 5-(4-phenoxybutoxy)psoralen (PAP-1) may be mediated by Kv1.5 rather than Kv1.3. PeerJ 2014. [PMID: 25320682 DOI: 10.7717/peerj.614.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Kv1 channels are shaker-related potassium channels that influence insulin sensitivity. Kv1.3(-/-) mice are protected from diet-induced insulin resistance and some studies suggest that Kv1.3 inhibitors provide similar protection. However, it is unclear whether blockade of Kv1.3 in adipocytes or skeletal muscle increases glucose uptake. There is no evidence that the related channel Kv1.5 has any influence on insulin sensitivity and its expression in adipose tissue has not been reported. PAP-1 is a selective inhibitor of Kv1.3, with 23-fold, 32-fold and 125-fold lower potencies as an inhibitor of Kv1.5, Kv1.1 and Kv1.2 respectively. Soleus muscles from wild-type and genetically obese ob/ob mice were incubated with 2-deoxy[1-(14)C]-glucose for 45 min and formation of 2-deoxy[1-(14)C]-glucose-6-phosphate was measured. White adipocytes were incubated with D-[U-(14)C]-glucose for 1 h. TNFα and Il-6 secretion from white adipose tissue pieces were measured by enzyme-linked-immunoassay. In the absence of insulin, a high concentration (3 µM) of PAP-1 stimulated 2-deoxy[1-14C]-glucose uptake in soleus muscle of wild-type and obese mice by 30% and 40% respectively, and in adipocytes by 20% and 50% respectively. PAP-1 also stimulated glucose uptake by adipocytes at the lower concentration of 1 µM, but at 300 nM, which is still 150-fold higher than its EC50 value for inhibition of the Kv1.3 channel, it had no effect. In the presence of insulin, PAP-1 (3 µM) had a significant effect only in adipocytes from obese mice. PAP-1 (3 µM) reduced the secretion of TNFα by adipose tissue but had no effect on the secretion of IL-6. Expression of Kv1.1, Kv1.2, Kv1.3 and Kv1.5 was determined by RT-PCR. Kv1.3 and Kv1.5 mRNA were detected in liver, gastrocnemius muscle, soleus muscle and white adipose tissue from wild-type and ob/ob mice, except that Kv1.3 could not be detected in gastrocnemius muscle, nor Kv1.5 in liver, of wild-type mice. Expression of both genes was generally higher in liver and muscle of ob/ob mice compared to wild-type mice. Kv1.5 appeared to be expressed more highly than Kv1.3 in soleus muscle, adipose tissue and adipocytes of wild-type mice. Expression of Kv1.2 appeared to be similar to that of Kv1.3 in soleus muscle and adipose tissue, but Kv1.2 was undetectable in adipocytes. Kv1.1 could not be detected in soleus muscle, adipose tissue or adipocytes. We conclude that inhibition of Kv1 channels by PAP-1 stimulates glucose uptake by adipocytes and soleus muscle of wild-type and ob/ob mice, and reduces the secretion of TNFα by adipose tissue. However, these effects are more likely due to inhibition of Kv1.5 than to inhibition of Kv1.3 channels.
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Affiliation(s)
- Robert A Ngala
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Mohamed S Zaibi
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Kenneth Langlands
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Claire J Stocker
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Jonathan R S Arch
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Michael A Cawthorne
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
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14
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Ngala RA, Zaibi MS, Langlands K, Stocker CJ, Arch JRS, Cawthorne MA. Stimulation of glucose uptake in murine soleus muscle and adipocytes by 5-(4-phenoxybutoxy)psoralen (PAP-1) may be mediated by Kv1.5 rather than Kv1.3. PeerJ 2014; 2:e614. [PMID: 25320682 PMCID: PMC4193404 DOI: 10.7717/peerj.614] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/17/2014] [Indexed: 01/08/2023] Open
Abstract
Kv1 channels are shaker-related potassium channels that influence insulin sensitivity. Kv1.3−/− mice are protected from diet-induced insulin resistance and some studies suggest that Kv1.3 inhibitors provide similar protection. However, it is unclear whether blockade of Kv1.3 in adipocytes or skeletal muscle increases glucose uptake. There is no evidence that the related channel Kv1.5 has any influence on insulin sensitivity and its expression in adipose tissue has not been reported. PAP-1 is a selective inhibitor of Kv1.3, with 23-fold, 32-fold and 125-fold lower potencies as an inhibitor of Kv1.5, Kv1.1 and Kv1.2 respectively. Soleus muscles from wild-type and genetically obese ob/ob mice were incubated with 2-deoxy[1-14C]-glucose for 45 min and formation of 2-deoxy[1-14C]-glucose-6-phosphate was measured. White adipocytes were incubated with D-[U-14C]-glucose for 1 h. TNFα and Il-6 secretion from white adipose tissue pieces were measured by enzyme-linked-immunoassay. In the absence of insulin, a high concentration (3 µM) of PAP-1 stimulated 2-deoxy[1-14C]-glucose uptake in soleus muscle of wild-type and obese mice by 30% and 40% respectively, and in adipocytes by 20% and 50% respectively. PAP-1 also stimulated glucose uptake by adipocytes at the lower concentration of 1 µM, but at 300 nM, which is still 150-fold higher than its EC50 value for inhibition of the Kv1.3 channel, it had no effect. In the presence of insulin, PAP-1 (3 µM) had a significant effect only in adipocytes from obese mice. PAP-1 (3 µM) reduced the secretion of TNFα by adipose tissue but had no effect on the secretion of IL-6. Expression of Kv1.1, Kv1.2, Kv1.3 and Kv1.5 was determined by RT-PCR. Kv1.3 and Kv1.5 mRNA were detected in liver, gastrocnemius muscle, soleus muscle and white adipose tissue from wild-type and ob/ob mice, except that Kv1.3 could not be detected in gastrocnemius muscle, nor Kv1.5 in liver, of wild-type mice. Expression of both genes was generally higher in liver and muscle of ob/ob mice compared to wild-type mice. Kv1.5 appeared to be expressed more highly than Kv1.3 in soleus muscle, adipose tissue and adipocytes of wild-type mice. Expression of Kv1.2 appeared to be similar to that of Kv1.3 in soleus muscle and adipose tissue, but Kv1.2 was undetectable in adipocytes. Kv1.1 could not be detected in soleus muscle, adipose tissue or adipocytes. We conclude that inhibition of Kv1 channels by PAP-1 stimulates glucose uptake by adipocytes and soleus muscle of wild-type and ob/ob mice, and reduces the secretion of TNFα by adipose tissue. However, these effects are more likely due to inhibition of Kv1.5 than to inhibition of Kv1.3 channels.
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Affiliation(s)
- Robert A Ngala
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Mohamed S Zaibi
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Kenneth Langlands
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Claire J Stocker
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Jonathan R S Arch
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Michael A Cawthorne
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
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15
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Ciccarelli M, Santulli G, Pascale V, Trimarco B, Iaccarino G. Adrenergic receptors and metabolism: role in development of cardiovascular disease. Front Physiol 2013; 4:265. [PMID: 24106479 PMCID: PMC3789271 DOI: 10.3389/fphys.2013.00265] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/08/2013] [Indexed: 01/08/2023] Open
Abstract
Activation of the adrenergic system has a profound effects on metabolism. Increased circulating catecholamine and activation of the different adrenergic receptors deployed in the various organs produce important metabolic responses which include: (1) increased lipolysis and elevated levels of fatty acids in plasma, (2) increased gluconeogenesis by the liver to provide substrate for the brain, and (3) moderate inhibition of insulin release by the pancreas to conserve glucose and to shift fuel metabolism of muscle in the direction of fatty acid oxidation. These physiological responses, typical of the stress conditions, are demonstrated to be detrimental for the functioning of different organs like the cardiac muscle when they become chronic. Indeed, a common feature of many pathological conditions involving over-activation of the adrenergic system is the development of metabolic alterations which can include insulin resistance, altered glucose and lipid metabolism and mitochondrial dysfunction. These patterns are involved with a variably extent among the different pathologies, however, they are in general strictly correlated to the level of activation of the adrenergic system. Here we will review the effects of the different adrenergic receptors subtypes on the metabolic variation observed in important disease like Heart Failure.
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Affiliation(s)
- Michele Ciccarelli
- Department of Medicine and Surgery, University of Salerno Salerno, Italy ; Center for Translational Medicine, Department of Pharmacology, Temple University of Philadelphia PA, USA
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16
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Evans BA, Hutchinson DS, Summers RJ. β2-Adrenoceptor-mediated regulation of glucose uptake in skeletal muscle--ligand-directed signalling or a reflection of system complexity? Naunyn Schmiedebergs Arch Pharmacol 2013; 386:757-60. [PMID: 23657252 DOI: 10.1007/s00210-013-0879-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 04/24/2013] [Indexed: 01/14/2023]
Abstract
The capacity of G protein-coupled receptors (GPCRs) to activate multiple G protein isoforms and additional effectors such as β-arrestins has become a well-established paradigm and provides the basis for developing drugs that preferentially activate beneficial signalling pathways. There are many published examples of ligand-directed signalling, and recent studies have provided direct evidence that different agonists stabilise distinct GPCR conformations. This field is rapidly evolving, but a key question is whether signalling bias observed in heterologous cell expression systems can be translated to physiological systems of therapeutic relevance. The paper by Ngala et al. in this issue of the journal addresses the capacity of agonists acting at the β2-adrenoceptor to engender signalling bias in relation to glucose uptake in isolated skeletal muscle, an area of considerable potential interest in targeting insulin-independent pathways for the treatment of type 2 diabetes. The authors show that clenbuterol and BRL37344 have opposite effects on glucose uptake, despite both having agonist actions at β2-adrenoceptors. This study underlines some of the obstacles associated with studies in a complex physiological system but nonetheless highlights the need to consider signalling bias in the relevant target tissue when developing novel drugs.
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Affiliation(s)
- Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, 399 Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
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17
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β2-adrenoceptor agonists can both stimulate and inhibit glucose uptake in mouse soleus muscle through ligand-directed signalling. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2013; 386:761-73. [PMID: 23564017 DOI: 10.1007/s00210-013-0860-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 03/22/2013] [Indexed: 10/27/2022]
Abstract
The β-adrenoceptor agonists BRL37344 and clenbuterol have opposite effects on glucose uptake in mouse soleus muscle, even though the β2-adrenoceptor mediates both effects. Different agonists may direct the soleus muscle β2-adrenoceptor to different signalling mechanisms. Soleus muscles were incubated with 2-deoxy[1-(14)C]-glucose, β-adrenoceptor agonists, other modulators of cyclic AMP, and inhibitors of intracellular signalling. The adenylyl cyclase activator forskolin (1 μM), the phosphodiesterase inhibitor rolipram (10 μM) and BRL37344 (10, but not 100 or 1,000, nM) increased, whereas clenbuterol (100 nM) decreased, glucose uptake. Forskolin increased, whereas clenbuterol decreased, muscle cyclic AMP content. BRL37344 (10 nM) did not increase cyclic AMP. Nevertheless, protein kinase A (PKA) inhibitors prevented the stimulatory effect of BRL37344. Nanomolar but not micromolar concentrations of adrenaline stimulated glucose uptake. After preincubation of muscles with pertussis toxin (100 ng/ml), 100 nM clenbuterol, 0.1-10 μM adrenaline and 100 nM BRL37344 stimulated glucose uptake. Clenbuterol increased the proportion of phosphorylated to total β2-adrenoceptor. Inhibitors of phosphatidylinositol 3-kinase (PI3K) and the stress-activated mitogen-activated protein kinase (MAPK), but not of the classical MAPK pathway, prevented stimulation of glucose uptake by BRL37344. Elevation of the cyclic AMP content of soleus muscle stimulates glucose uptake. Clenbuterol, and high concentrations of adrenaline and BRL37344 direct the β2-adrenoceptor partly to Gαi, possibly mediated by β2-adrenoceptor phosphorylation. The stimulatory effect of 10 nM BRL37344 requires the activity of PKA, PI3K and p38 MAPK, consistent with BRL37344 directing the β2-adrenoceptor to Gαs. Ligand-directed signalling may explain why β2-adrenoceptor agonists have differing effects on glucose uptake in soleus muscle.
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18
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Pérez-Schindler J, Philp A, Hernandez-Cascales J. Pathophysiological relevance of the cardiac β2-adrenergic receptor and its potential as a therapeutic target to improve cardiac function. Eur J Pharmacol 2012. [PMID: 23183106 DOI: 10.1016/j.ejphar.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
β-adrenoceptors are members of the G protein-coupled receptor superfamily which play a key role in the regulation of myocardial function. Their activation increases cardiac performance but can also induce deleterious effects such as cardiac arrhythmias or myocardial apoptosis. In fact, inhibition of β-adrenoceptors exerts a protective effect in patients with sympathetic over-stimulation during heart failure. Although β(2)-adrenoceptor is not the predominant subtype in the heart, it seems to importantly contribute to the cardiac effects of adrenergic stimulation; however, the mechanism by which this occurs is not fully understood. This review summarizes the current knowledge on the role of β(2)-adrenoceptors in the regulation of cardiac contractility, metabolism, cardiomyocyte survival and cardiac arrhythmias. In addition, therapeutic considerations relating to stimulation of the β(2)-adrenoceptor such as an increase in cardiac contractility with low arrythmogenic effect, protection of the myocardium again apoptosis or positive regulation of heart metabolism are discussed.
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Male mice that lack the G-protein-coupled receptor GPR41 have low energy expenditure and increased body fat content. Br J Nutr 2012; 109:1755-64. [PMID: 23110765 DOI: 10.1017/s0007114512003923] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
SCFA are produced in the gut by bacterial fermentation of undigested carbohydrates. Activation of the Gαi-protein-coupled receptor GPR41 by SCFA in β-cells and sympathetic ganglia inhibits insulin secretion and increases sympathetic outflow, respectively. A possible role in stimulating leptin secretion by adipocytes is disputed. In the present study, we investigated energy balance and glucose homoeostasis in GPR41 knockout mice fed on a standard low-fat or a high-fat diet. When fed on the low-fat diet, body fat mass was raised and glucose tolerance was impaired in male but not female knockout mice compared to wild-type mice. Soleus muscle and heart weights were reduced in the male mice, but total body lean mass was unchanged. When fed on the high-fat diet, body fat mass was raised in male but not female GPR41 knockout mice, but by no more in the males than when they were fed on the low-fat diet. Body lean mass and energy expenditure were reduced in male mice but not in female knockout mice. These results suggest that the absence of GPR41 increases body fat content in male mice. Gut-derived SCFA may raise energy expenditure and help to protect against obesity by activating GPR41.
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Dehvari N, Hutchinson DS, Nevzorova J, Dallner OS, Sato M, Kocan M, Merlin J, Evans BA, Summers RJ, Bengtsson T. β(2)-Adrenoceptors increase translocation of GLUT4 via GPCR kinase sites in the receptor C-terminal tail. Br J Pharmacol 2012; 165:1442-56. [PMID: 21883150 DOI: 10.1111/j.1476-5381.2011.01647.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE β-Adrenoceptor stimulation induces glucose uptake in several insulin-sensitive tissues by poorly understood mechanisms. EXPERIMENTAL APPROACH We used a model system in CHO-K1 cells expressing the human β(2)-adrenoceptor and glucose transporter 4 (GLUT4) to investigate the signalling mechanisms involved. KEY RESULTS In CHO-K1 cells, there was no response to β-adrenoceptor agonists. The introduction of β(2)-adrenoceptors and GLUT4 into these cells caused increased glucose uptake in response to β-adrenoceptor agonists. GLUT4 translocation occurred in response to insulin and β(2)-adrenoceptor stimulation, although the key insulin signalling intermediate PKB was not phosphorylated in response to β(2)-adrenoceptor stimulation. Truncation of the C-terminus of the β(2)-adrenoceptor at position 349 to remove known phosphorylation sites for GPCR kinases (GRKs) or at position 344 to remove an additional PKA site together with the GRK phosphorylation sites did not significantly affect cAMP accumulation but decreased β(2)-adrenoceptor-stimulated glucose uptake. Furthermore, inhibition of GRK by transfection of the βARKct construct inhibited β(2)-adrenoceptor-mediated glucose uptake and GLUT4 translocation, and overexpression of a kinase-dead GRK2 mutant (GRK2 K220R) also inhibited GLUT4 translocation. Introducing β(2)-adrenoceptors lacking phosphorylation sites for GRK or PKA demonstrated that the GRK sites, but not the PKA sites, were necessary for GLUT4 translocation. CONCLUSIONS AND IMPLICATIONS Glucose uptake in response to activation of β(2)-adrenoceptors involves translocation of GLUT4 in this model system. The mechanism is dependent on the C-terminus of the β(2)-adrenoceptor, requires GRK phosphorylation sites, and involves a signalling pathway distinct from that stimulated by insulin.
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Affiliation(s)
- Nodi Dehvari
- Department of Physiology, The Wenner-Gren Institute, Arrhenius Laboratories F3, Stockholm University, Stockholm, Sweden
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21
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Ngala RA, Stocker CJ, Roy AG, Hislop D, Wargent E, Bell R, Hassall DG, Harling JD, Billin AN, Willson TM, Arch JRS, Cawthorne MA. A new, highly selective murine peroxisome proliferator-activated receptor δ agonist increases responsiveness to thermogenic stimuli and glucose uptake in skeletal muscle in obese mice. Diabetes Obes Metab 2011; 13:455-64. [PMID: 21272187 DOI: 10.1111/j.1463-1326.2011.01371.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM We investigated how GW800644, the first pharmacologically selective murine peroxisome proliferator-activated receptor δ (PPARδ) agonist, affects energy balance, glucose homeostasis and fuel utilization by muscle in obese mice. METHODS Potencies were determined in transactivation assays. Oral glucose tolerance was determined after 14 and 22 days' administration (10 mg/kg body weight, twice daily) to Lep(ob)/Lep(ob) mice. Food intake and energy expenditure were measured during a 26-day experiment, and plasma metabolites and 2-deoxyglucose uptake in vivo at termination. Palmitate oxidation and 2-deoxyglucose uptake by isolated soleus muscles were measured after 14 (in lean and obese mice) and 26 days. RESULTS GW800644 activated murine PPARδ (EC(50) 2 nM), but caused little to no activation of PPARα or PPARγ up to 10 µM. It did not increase liver weight. GW800644 reduced food intake and body weight in obese mice after 8 days. It did not affect resting energy expenditure, but, compared to pair-fed mice, it increased the response to a β(3)-adrenoceptor agonist. It improved glucose tolerance. GW800644, but not pair-feeding, reduced plasma glucose, insulin and triglyceride concentrations. It increased 2-deoxyglucose uptake in vivo in adipose tissue, soleus muscle, heart, brain and liver, and doubled 2-deoxyglucose uptake and palmitate oxidation in isolated soleus muscle from obese but not lean mice. CONCLUSIONS PPARδ agonism reduced food intake and independently elicited metabolic effects that included increased responsiveness to β(3)-adrenoceptor stimulation, increased glucose utilization and fat oxidation in soleus muscle of Lep(ob)/Lep(ob) but not lean mice and increased glucose utilization in vivo in Lep(ob)/Lep(ob) mice.
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Affiliation(s)
- R A Ngala
- Clore Laboratory, University of Buckingham, UK
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22
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Regulation of contractility and metabolic signaling by the β2-adrenergic receptor in rat ventricular muscle. Life Sci 2011; 88:892-7. [PMID: 21466811 DOI: 10.1016/j.lfs.2011.03.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 03/08/2011] [Accepted: 03/25/2011] [Indexed: 01/12/2023]
Abstract
AIMS Cardiac function is modulated by the sympathetic nervous system through β-adrenergic receptor (β-AR) activity and this represents the main regulatory mechanism for cardiac performance. To date, however, the metabolic and molecular responses to β(2)-agonists are not well characterized. Therefore, we studied the inotropic effect and signaling response to selective β(2)-AR activation by tulobuterol. MAIN METHODS Strips of rat right ventricle were electrically stimulated (1Hz) in standard Tyrode solution (95% O(2), 5% CO(2)) in the presence of the β(1)-antagonist CGP-20712A (1μM). A cumulative dose-response curve for tulobuterol (0.1-10μM), in the presence or absence of the phosphodiesterase (PDE) inhibitor IBMX (30μM), or 10min incubation (1μM) with the β(2)-agonist tulobuterol was performed. KEY FINDINGS β(2)-AR stimulation induced a positive inotropic effect (maximal effect=33±3.3%) and a decrease in the time required for half relaxation (from 45±0.6 to 31±1.8ms, -30%, p<0.001) after the inhibition of PDEs. After 10min of β(2)-AR stimulation, p-AMPKα(T172) (54%), p-PKB(T308) (38%), p-AS160(T642) (46%) and p-CREB(S133) (63%) increased, without any change in p-PKA(T197). SIGNIFICANCE These results suggest that the regulation of ventricular contractility is not the primary function of the β(2)-AR. Rather, β(2)-AR could function to activate PKB and AMPK signaling, thereby modulating muscle mass and energetic metabolism of rat ventricular muscle.
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Abstract
This themed section of BJP includes 11 reviews on the biology of G-protein coupled receptors (GPCRs) and the drug targets that these present, 21 research papers on the pharmacology of a range of GPCRs and Commentaries on four of the papers. Areas reviewed include molecular interactions, particular in respect of hetero-dimerisation between receptors and other membrane-located proteins and other key signalling molecules including cAMP and G12/13 proteins and recently de-orphanised receptors including the Neuromedins U & S and the Free Fatty Acid receptors FFA2 & FFA3. The research papers cover the pharmacology of a range of agents acting at GPCRs, including adrenoceptors, purinoceptors, 5HT, opioid, cannabinoid & PAR-2 receptors. A group of papers is concerned with the interesting and rapidly developing pharmacology of drugs acting at beta(2)-adrenoceptors. The reach of GPCRs is illustrated by the range of physiological systems and therapeutic applications involved, including pain, cancer, cardiovascular, gastrointestinal, visual and respiratory and central nervous systems.
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Ngala RA, O'Dowd J, Wang SJ, Stocker C, Cawthorne MA, Arch JRS. Beta2-adrenoceptors and non-beta-adrenoceptors mediate effects of BRL37344 and clenbuterol on glucose uptake in soleus muscle: studies using knockout mice. Br J Pharmacol 2010; 158:1676-82. [PMID: 19912225 DOI: 10.1111/j.1476-5381.2009.00472.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE In previous work, 10 pM BRL37344 and 10 pM clenbuterol stimulated glucose uptake in mouse soleus muscle. Ten nM BRL37344 also stimulated uptake but 100 nM clenbuterol inhibited uptake. Antagonist studies suggested that the opposite effects of 10 nM BRL37344 and 100 nM clenbuterol are mediated by the beta(2)-adrenoceptor. BRL37344 and clenbuterol have been studied in muscles that lack beta(3)-, beta(2)- or all three beta-adrenoceptors. Effects of beta-adrenoceptor antagonists on responses to the agonists have been studied further using muscles from wild-type mice. EXPERIMENTAL APPROACH Soleus muscles of wild-type or beta-adrenoceptor knockout mice were incubated with 2-deoxy[1-(14)C]-glucose, and beta-adrenoceptor ligands. Formation of 2-deoxy[1-(14)C]-glucose-6-phosphate was measured. KEY RESULTS Concentration-response relationships were similar for BRL37344 and clenbuterol in normal muscle and muscle lacking beta(3)-adrenoceptors. Ten pM BRL37344 and clenbuterol stimulated glucose uptake in muscle lacking beta(2)-adrenoceptors or all three beta-adrenoceptors, but 10 nM BRL37344 did not stimulate uptake in either case, and 100 nM clenbuterol stimulated, rather than inhibited, uptake in muscle lacking beta(2)-adrenoceptors. One hundred nM clenbuterol also stimulated glucose uptake in normal muscle when beta(2)-adrenoceptors were blocked with ICI118551, and this was not prevented by antagonism of beta(1)- or beta(3)-adrenoceptors. CONCLUSIONS AND IMPLICATIONS Ten nM BRL37344 and 100 nM clenbuterol have opposite effects on glucose uptake but both effects are mediated by the beta(2)-adrenoceptor - apparently an example of agonist-directed signalling. Ten pM BRL37344, 10 pM clenbuterol and 100 nM clenbuterol in the presence of ICI118551 stimulate glucose uptake via beta-adrenoceptor-independent mechanisms, demonstrating unknown properties for the agonists.
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Affiliation(s)
- Robert A Ngala
- Clore Laboratory, University of Buckingham, Buckingham, UK
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Abstract
Beta-Adrenoceptors are one of the most widely studied groups of G-protein-coupled receptors but continue to provide surprises and insights that have general relevance to pharmacology. Atypical pharmacologies have been described for ligands formerly (and still) described as antagonists acting at beta(1)-, beta(2)- and beta(3)-adrenoceptors that involve ligand-directed signalling and possibly allosteric interactions at the receptors. In the article by Ngala et al., in this issue of the Br J Pharmacol, another example of atypical interactions with beta-adrenoceptors is described, this time for agonists. Some of the responses to BRL37344 and clenbuterol can be explained in terms of actions at beta(2)-adrenoceptors, whereas others such as the increased glucose uptake and palmitate oxidation observed with pM concentrations of BRL37344 may involve interactions with other (possibly allosteric) sites. Atypical pharmacologies of ligands acting at beta-adrenoceptors have already indicated new ways in which ligands can interact with G-protein-coupled receptors and these mechanisms are likely to have important consequences for future drug development.
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