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Michel MC, Michel-Reher MB, Hein P. A Systematic Review of Inverse Agonism at Adrenoceptor Subtypes. Cells 2020; 9:E1923. [PMID: 32825009 PMCID: PMC7564766 DOI: 10.3390/cells9091923] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 12/18/2022] Open
Abstract
As many, if not most, ligands at G protein-coupled receptor antagonists are inverse agonists, we systematically reviewed inverse agonism at the nine adrenoceptor subtypes. Except for β3-adrenoceptors, inverse agonism has been reported for each of the adrenoceptor subtypes, most often for β2-adrenoceptors, including endogenously expressed receptors in human tissues. As with other receptors, the detection and degree of inverse agonism depend on the cells and tissues under investigation, i.e., they are greatest when the model has a high intrinsic tone/constitutive activity for the response being studied. Accordingly, they may differ between parts of a tissue, for instance, atria vs. ventricles of the heart, and within a cell type, between cellular responses. The basal tone of endogenously expressed receptors is often low, leading to less consistent detection and a lesser extent of observed inverse agonism. Extent inverse agonism depends on specific molecular properties of a compound, but inverse agonism appears to be more common in certain chemical classes. While inverse agonism is a fascinating facet in attempts to mechanistically understand observed drug effects, we are skeptical whether an a priori definition of the extent of inverse agonism in the target product profile of a developmental candidate is a meaningful option in drug discovery and development.
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Affiliation(s)
- Martin C. Michel
- Department of Pharmacology, Johannes Gutenberg University, 55131 Mainz, Germany;
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Gao X, Yang L, Bai Y, Li Q, Zhao X, Bian L, Zheng X. Screening of bioactive components from traditional Chinese medicine by immobilized β 2 adrenergic receptor coupled with high performance liquid chromatography/mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1134-1135:121782. [PMID: 31778946 DOI: 10.1016/j.jchromb.2019.121782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 10/26/2022]
Abstract
Traditional Chinese medicine (TCM) represents a valuable resource for lead compounds discovery. Given the complexity of TCM components, analytical methods play a key role in novel drug development. In our study, we established a high specific and reliable bio-active components screen system, where β2 adrenergic receptor (β2-AR) was immobilized on silica by non-covalent bonds and packed into a stainless steel column (4.6 × 50 mm, 7 μm) to form β2-AR chromatography column. The column was further coupled with high performance liquid chromatography-time of flight tandem mass spectrometry (TOF-MS/MS). By utilizing this strategy, we successfully identified four β2-AR-targeting compounds: tetrahydroberberine, tetrahydrocolumbamine, fumarine and corydaline from Corydalis Rhizome. The association constants between β2-AR and tetrahydroberberine (9.04 × 104/M) as well as fumarine (4.30 × 104/M) were determined by frontal chromatography. We also found that these two compounds shared the identical binding site on immobilized β2-AR with corresponding concentrations of 6.67 × 10-4 M and 5.88 × 10-4 M, respectively. The newly established method represents an efficient tool to identify the target specific natural compounds.
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Affiliation(s)
- Xiaokang Gao
- School of Pharmaceutical Sciences, Hubei University of Medicine, Shiyan 442000, Hubei, China; Hubei Key Laboratory of Embryonic Stem Cell Research, Taihe Hospital, Shiyan 442000, Hubei, China; Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Lingjian Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Yajun Bai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Qian Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Xinfeng Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Liujiao Bian
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China
| | - Xiaohui Zheng
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi'an 710069, China.
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Gao X, Yang L, Li Q, An Y, Liao S, Gao H, Zhao X, Bian L, Zheng X. Investigation on temperature-induce conformational change of immobilized β 2 adrenergic receptor. Biochem Biophys Res Commun 2017; 494:634-640. [PMID: 28851653 DOI: 10.1016/j.bbrc.2017.08.105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 08/25/2017] [Indexed: 11/17/2022]
Abstract
The β2 adrenergic receptor (β2-AR) is a prototypical family A G protein-coupled receptor (GPCR) and an excellent model system for studying the mechanism of GPCR activation. Purified β2-AR was immobilized on macroporous silica gel to obtain liquid chromatographic stationary phase. The resulting phase was packed into a stainless steel column (4.6 × 50 mm, 7 μm) and used for on-line chromatographic system. When column oven temperature increased from 20.0 °C to 40.0 °C, uncomplete separate chromatographic peaks of ephedrine and pseudoephedrine as receptor conformational probe were gradually merged into one peak, meanwhile retention time and resolution of the probes were reduced correspondingly, which suggested that temperature could regulate protein conformation. Temperature-induced conformational change of immobilized β2-AR, especially changes at higher temperatures, indicated that constructed receptor chromatography could simulate fever disease state of human body and clarify receptor conformation change at pathological condition. At the same time this study could also provide new ideas for screening active components in pathological conditions.
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Affiliation(s)
- Xiaokang Gao
- School of Pharmaceutical Sciences, Hubei Key Laboratory of Wudang Local Chinese Medicine Research, Hubei Provincial Technology and Research Center for Comprehensive Development of Medicinal Herbs, Hubei University of Medicine, Shiyan 442000, Hubei, China; College of Life Science, Northwest University, Xi'an 710069, China; Hubei Key Laboratory of Embryonic Stem Cell Research, Taihe Hospital, Shiyan 442000, Hubei, China
| | - Lingjian Yang
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Qian Li
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Yuxin An
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Sha Liao
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Haiyang Gao
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Xinfeng Zhao
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Liujiao Bian
- College of Life Science, Northwest University, Xi'an 710069, China
| | - Xiaohui Zheng
- College of Life Science, Northwest University, Xi'an 710069, China.
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Gupta MK, Asosingh K, Aronica M, Comhair S, Cao G, Erzurum S, Panettieri RA, Naga Prasad SV. Defective Resensitization in Human Airway Smooth Muscle Cells Evokes β-Adrenergic Receptor Dysfunction in Severe Asthma. PLoS One 2015; 10:e0125803. [PMID: 26023787 PMCID: PMC4449172 DOI: 10.1371/journal.pone.0125803] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/18/2015] [Indexed: 12/21/2022] Open
Abstract
β2-adrenergic receptor (β2AR) agonists (β2-agonist) are the most commonly used therapy for acute relief in asthma, but chronic use of these bronchodilators paradoxically exacerbates airway hyper-responsiveness. Activation of βARs by β-agonist leads to desensitization (inactivation) by phosphorylation through G-protein coupled receptor kinases (GRKs) which mediate β-arrestin binding and βAR internalization. Resensitization occurs by dephosphorylation of the endosomal βARs which recycle back to the plasma membrane as agonist-ready receptors. To determine whether the loss in β-agonist response in asthma is due to altered βAR desensitization and/or resensitization, we used primary human airway smooth muscle cells (HASMCs) isolated from the lungs of non-asthmatic and fatal-asthmatic subjects. Asthmatic HASMCs have diminished adenylyl cyclase activity and cAMP response to β-agonist as compared to non-asthmatic HASMCs. Confocal microscopy showed significant accumulation of phosphorylated β2ARs in asthmatic HASMCs. Systematic analysis of desensitization components including GRKs and β-arrestin showed no appreciable differences between asthmatic and non-asthmatic HASMCs. However, asthmatic HASMC showed significant increase in PI3Kγ activity and was associated with reduction in PP2A activity. Since reduction in PP2A activity could alter receptor resensitization, endosomal fractions were isolated to assess the agonist ready β2ARs as a measure of resensitization. Despite significant accumulation of β2ARs in the endosomes of asthmatic HASMCs, endosomal β2ARs cannot robustly activate adenylyl cyclase. Furthermore, endosomes from asthmatic HASMCs are associated with significant increase in PI3Kγ and reduced PP2A activity that inhibits β2AR resensitization. Our study shows that resensitization, a process considered to be a homeostasis maintaining passive process is inhibited in asthmatic HASMCs contributing to β2AR dysfunction which may underlie asthma pathophysiology and loss in asthma control.
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Affiliation(s)
- Manveen K. Gupta
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Kewal Asosingh
- Department of Pathology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Mark Aronica
- Department of Pathology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Suzy Comhair
- Department of Pathology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Gaoyuan Cao
- Airways Biology Initiative, Pulmonary, Allergy and Critical Care Division, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Serpil Erzurum
- Department of Pathology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Reynold A. Panettieri
- Airways Biology Initiative, Pulmonary, Allergy and Critical Care Division, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sathyamangla V. Naga Prasad
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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Oldenburger A, Maarsingh H, Schmidt M. Multiple facets of cAMP signalling and physiological impact: cAMP compartmentalization in the lung. Pharmaceuticals (Basel) 2012; 5:1291-331. [PMID: 24281338 PMCID: PMC3816672 DOI: 10.3390/ph5121291] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 11/15/2012] [Accepted: 11/20/2012] [Indexed: 12/20/2022] Open
Abstract
Therapies involving elevation of the endogenous suppressor cyclic AMP (cAMP) are currently used in the treatment of several chronic inflammatory disorders, including chronic obstructive pulmonary disease (COPD). Characteristics of COPD are airway obstruction, airway inflammation and airway remodelling, processes encompassed by increased airway smooth muscle mass, epithelial changes, goblet cell and submucosal gland hyperplasia. In addition to inflammatory cells, airway smooth muscle cells and (myo)fibroblasts, epithelial cells underpin a variety of key responses in the airways such as inflammatory cytokine release, airway remodelling, mucus hypersecretion and airway barrier function. Cigarette smoke, being next to environmental pollution the main cause of COPD, is believed to cause epithelial hyperpermeability by disrupting the barrier function. Here we will focus on the most recent progress on compartmentalized signalling by cAMP. In addition to G protein-coupled receptors, adenylyl cyclases, cAMP-specific phospho-diesterases (PDEs) maintain compartmentalized cAMP signalling. Intriguingly, spatially discrete cAMP-sensing signalling complexes seem also to involve distinct members of the A-kinase anchoring (AKAP) superfamily and IQ motif containing GTPase activating protein (IQGAPs). In this review, we will highlight the interaction between cAMP and the epithelial barrier to retain proper lung function and to alleviate COPD symptoms and focus on the possible molecular mechanisms involved in this process. Future studies should include the development of cAMP-sensing multiprotein complex specific disruptors and/or stabilizers to orchestrate cellular functions. Compartmentalized cAMP signalling regulates important cellular processes in the lung and may serve as a therapeutic target.
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Affiliation(s)
- Anouk Oldenburger
- Department of Molecular Pharmacology, Groningen Research Institute for Pharmacy, University of Groningen, 9713 AV, Groningen, The Netherlands.
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Dekkers BGJ, Racké K, Schmidt M. Distinct PKA and Epac compartmentalization in airway function and plasticity. Pharmacol Ther 2012; 137:248-65. [PMID: 23089371 DOI: 10.1016/j.pharmthera.2012.10.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 12/15/2022]
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibroblasts, substantially contribute to disease features by the release of inflammatory mediators, smooth muscle contraction, extracellular matrix deposition and structural changes in the airways. Current pharmacological treatment of both diseases intends to target the dynamic features of the endogenous intracellular suppressor cyclic AMP (cAMP). This review will summarize our current knowledge on cAMP and will emphasize on key discoveries and paradigm shifts reflecting the complex spatio-temporal nature of compartmentalized cAMP signalling networks in health and disease. As airway fibroblasts and airway smooth muscle cells are recognized as central players in the development and progression of asthma and COPD, we will focus on the role of cAMP signalling in their function in relation to airway function and plasticity. We will recapture on the recent identification of cAMP-sensing multi-protein complexes maintained by cAMP effectors, including A-kinase anchoring proteins (AKAPs), proteins kinase A (PKA), exchange protein directly activated by cAMP (Epac), cAMP-elevating seven-transmembrane (7TM) receptors and phosphodiesterases (PDEs) and we will report on findings indicating that the pertubation of compartmentalized cAMP signalling correlates with the pathopysiology of obstructive lung diseases. Future challenges include studies on cAMP dynamics and compartmentalization in the lung and the development of novel drugs targeting these systems for therapeutic interventions in chronic obstructive inflammatory diseases.
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Affiliation(s)
- Bart G J Dekkers
- Department of Molecular Pharmacology, University Center of Pharmacy, University of Groningen, The Netherlands.
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Billington CK, Hall IP. Novel cAMP signalling paradigms: therapeutic implications for airway disease. Br J Pharmacol 2012; 166:401-10. [PMID: 22013890 DOI: 10.1111/j.1476-5381.2011.01719.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Since its discovery over 50 years ago, cAMP has been the archetypal second messenger introducing students to the concept of cell signalling at the simplest level. As explored in this review, however, there are many more facets to cAMP signalling than the path from Gs-coupled receptor to adenylyl cyclase (AC) to cAMP to PKA to biological effect. After a brief description of this canonical cAMP signalling pathway, a snapshot is provided of the novel paradigms of cAMP signalling. As in the airway the cAMP pathway relays the major bronchorelaxant signal and as such is the target for frontline therapy for asthma and COPD, particular emphasis is given to airway disease and therapy. Areas discussed include biased agonism, continued signalling following internalization, modulation of cAMP by AC, control of cAMP degradation, cAMP and calcium crosstalk, Epac-mediated signalling and finally the implications of altered genotypes will be considered. LINKED ARTICLES This article is part of a themed section on Novel cAMP Signalling Paradigms. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.166.issue-2.
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Affiliation(s)
- Charlotte K Billington
- Division of Therapeutics and Molecular Medicine, Nottingham Respiratory Biomedical Research Unit, The University of Nottingham, Nottingham, UK.
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Siddiqui S, Redhu NS, Ojo OO, Liu B, Irechukwu N, Billington C, Janssen L, Moir LM. Emerging airway smooth muscle targets to treat asthma. Pulm Pharmacol Ther 2012; 26:132-44. [PMID: 22981423 DOI: 10.1016/j.pupt.2012.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 07/28/2012] [Accepted: 08/27/2012] [Indexed: 11/26/2022]
Abstract
Asthma is characterized in part by variable airflow obstruction and non-specific hyperresponsiveness to a variety of bronchoconstrictors, both of which are mediated by the airway smooth muscle (ASM). The ASM is also involved in the airway inflammation and airway wall remodeling observed in asthma. For all these reasons, the ASM provides an important target for the treatment of asthma. Several classes of drugs were developed decades ago which targeted the ASM - including β-agonists, anti-cholinergics, anti-histamines and anti-leukotrienes - but no substantially new class of drug has appeared recently. In this review, we summarize the on-going work of several laboratories aimed at producing novel targets and/or tools for the treatment of asthma. These range from receptors and ion channels on the ASM plasmalemma, to intracellular effectors (particularly those related to cyclic nucleotide signaling, calcium-homeostasis and phosphorylation cascades), to anti-IgE therapy and outright destruction of the ASM itself.
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Affiliation(s)
- Sana Siddiqui
- Meakins-Christie Laboratories, Department of Medicine, McGill University, 3626 St Urbain, Montréal, Québec H2X 2P2, Canada
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Ferrie AM, Sun H, Fang Y. Label-free integrative pharmacology on-target of drugs at the β(2)-adrenergic receptor. Sci Rep 2011; 1:33. [PMID: 22355552 PMCID: PMC3216520 DOI: 10.1038/srep00033] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 06/23/2011] [Indexed: 12/22/2022] Open
Abstract
We describe a label-free integrative pharmacology on-target (iPOT) method to assess the pharmacology of drugs at the β(2)-adrenergic receptor. This method combines dynamic mass redistribution (DMR) assays using an array of probe molecule-hijacked cells with similarity analysis. The whole cell DMR assays track cell system-based, ligand-directed, and kinetics-dependent biased activities of the drugs, and translates their on-target pharmacology into numerical descriptors which are subject to similarity analysis. We demonstrate that the approach establishes an effective link between the label-free pharmacology and in vivo therapeutic indications of drugs.
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Affiliation(s)
- Ann M Ferrie
- Biochemical Technologies, Science and Technology Division, Corning Inc., Corning, NY 14831, USA
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Vasudevan NT, Mohan ML, Gupta MK, Hussain AK, Naga Prasad SV. Inhibition of protein phosphatase 2A activity by PI3Kγ regulates β-adrenergic receptor function. Mol Cell 2011; 41:636-48. [PMID: 21419339 DOI: 10.1016/j.molcel.2011.02.025] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 11/18/2010] [Accepted: 02/23/2011] [Indexed: 01/08/2023]
Abstract
Phosphoinositide 3-kinase γ (PI3Kγ) is activated by G protein-coupled receptors (GPCRs). We show here that PI3Kγ inhibits protein phosphatase 2A (PP2A) at the β-adrenergic receptor (βAR, a GPCR) complex altering G protein coupling. PI3Kγ inhibition results in significant increase of βAR-associated phosphatase activity leading to receptor dephosphorylation and resensitization preserving cardiac function. Mechanistically, PI3Kγ inhibits PP2A activity at the βAR complex by phosphorylating an intracellular inhibitor of PP2A (I2PP2A) on serine residues 9 and 93, resulting in enhanced binding to PP2A. Indeed, enhanced phosphorylation of β2ARs is observed with a phosphomimetic I2PP2A mutant that was completely reversed with a mutant mimicking dephosphorylated state. siRNA depletion of endogenous I2PP2A augments PP2A activity despite active PI3K resulting in β2AR dephosphorylation and sustained signaling. Our study provides the underpinnings of a PI3Kγ-mediated regulation of PP2A activity that has significant consequences on receptor function with broad implications in cellular signaling.
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Affiliation(s)
- Neelakantan T Vasudevan
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
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Yang Z, Cooper PR, Damera G, Mukhopadhyay I, Cho H, Kehrl JH, Panettieri RA, Druey KM. Beta-agonist-associated reduction in RGS5 expression promotes airway smooth muscle hyper-responsiveness. J Biol Chem 2011; 286:11444-55. [PMID: 21278382 DOI: 10.1074/jbc.m110.212480] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although short-acting and long-acting inhaled β(2)-adrenergic receptor agonists (SABA and LABA, respectively) relieve asthma symptoms, use of either agent alone without concomitant anti-inflammatory drugs (corticosteroids) may increase the risk of disease exacerbation in some patients. We found previously that pretreatment of human precision-cut lung slices (PCLS) with SABA impaired subsequent β(2)-agonist-induced bronchodilation, which occurred independently of changes in receptor quantities. Here we provide evidence that prolonged exposure of cultured human airway smooth muscle (HuASM) cells to β(2)-agonists directly augments procontractile signaling pathways elicited by several compounds including thrombin, bradykinin, and histamine. Such treatment did not increase surface receptor amounts or expression of G proteins and downstream effectors (phospholipase Cβ and myosin light chain). In contrast, β-agonists decreased expression of regulator of G protein signaling 5 (RGS5), which is an inhibitor of G-protein-coupled receptor (GPCR) activity. RGS5 knockdown in HuASM increased agonist-evoked intracellular calcium flux and myosin light chain (MLC) phosphorylation, which are prerequisites for contraction. PCLS from Rgs5(-/-) mice contracted more to carbachol than those from WT mice, indicating that RGS5 negatively regulates bronchial smooth muscle contraction. Repetitive β(2)-agonist use may not only lead to reduced bronchoprotection but also to sensitization of excitation-contraction signaling pathways as a result of reduced RGS5 expression.
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Affiliation(s)
- Zhao Yang
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, NIAID, National Institutes of Health, Bethesda, Maryland 20892, USA
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Clinical implications of the intrinsic efficacy of beta-adrenoceptor drugs in asthma: full, partial and inverse agonism. Curr Opin Pulm Med 2010; 16:1-5. [PMID: 19887938 DOI: 10.1097/mcp.0b013e328333def8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW beta2-Adrenoceptor (AR) agonists are the most effective bronchodilators known, and play important roles in every step of asthma therapy. Intrinsic efficacy is an important pharmacological property that differentiates the clinical effects and safety profile of beta2-AR agonists. We review the role of beta2-AR agonist intrinsic efficacy in asthma treatment focusing on recent literature. RECENT FINDINGS In acute asthma, a full agonist (high intrinsic efficacy) offers a clinical advantage over a partial agonist (low intrinsic efficacy) but with the potential of inducing dose-dependent adverse effects. The chronic use of beta2-AR agonists may be associated with several adverse outcomes including loss of asthma control and even increased mortality. Recently, the role of beta-AR inverse agonists (beta-blockers) which have a negative intrinsic efficacy was studied. Whereas contraindicated in acute asthma, preliminary data suggest that the chronic use of these agents may be associated with attenuation of airway hyper-responsiveness in patients with mild asthma. Studies in a murine model of asthma suggest that such effects may be related to decreased airway inflammation and mucous metaplasia. SUMMARY Rational choice among beta2-AR agonists in acute and chronic asthma should be influenced by differences in intrinsic efficacy among these agents. In acute severe asthma, a full agonist offers a clinical advantage over a partial agonist. Whereas the use of inverse agonists in the treatment of asthma is still experimental and needs further exploration in future trials, preliminary studies suggest that their chronic use is well tolerated and is associated with decreased airway hyper-responsiveness.
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Zhang X, Chien EY, Chalmers MJ, Pascal BD, Gatchalian J, Stevens RC, Griffin PR. Dynamics of the beta2-adrenergic G-protein coupled receptor revealed by hydrogen-deuterium exchange. Anal Chem 2010; 82:1100-8. [PMID: 20058880 PMCID: PMC2829980 DOI: 10.1021/ac902484p] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To examine the molecular details of ligand activation of G-protein coupled receptors (GPCRs), emphasis has been placed on structure determination of these receptors with stabilizing ligands. Here we present the methodology for receptor dynamics characterization of the GPCR human beta(2) adrenergic receptor bound to the inverse agonist carazolol using the technique of amide hydrogen/deuterium exchange coupled with mass spectrometry (HDX MS). The HDX MS profile of receptor bound to carazolol is consistent with thermal parameter observations in the crystal structure and provides additional information in highly dynamic regions of the receptor and chemical modifications demonstrating the highly complementary nature of the techniques. After optimization of HDX experimental conditions for this membrane protein, better than 89% sequence coverage was obtained for the receptor. The methodology presented paves the way for future analysis of beta(2)AR bound to pharmacologically distinct ligands as well as analysis of other GPCR family members.
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Affiliation(s)
- Xi Zhang
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Ellen Y.T. Chien
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Michael J. Chalmers
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Bruce D. Pascal
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
| | - Jovylyn Gatchalian
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Raymond C. Stevens
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Patrick R. Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458
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