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Ge M, Wu L, He F, Tai Y, Fang R, Han D, Guo P, Liu H, Hu Y, Xu S, Wei W, Wang Q. CP-25 inhibits the hyperactivation of rheumatic synoviocytes by suppressing the switch in G αs-G αi coupling to the β 2-adrenergic receptor. Cell Commun Signal 2023; 21:346. [PMID: 38037039 PMCID: PMC10688045 DOI: 10.1186/s12964-023-01358-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/16/2023] [Indexed: 12/02/2023] Open
Abstract
In essence, the β2 adrenergic receptor (β2AR) plays an antiproliferative role by increasing the intracellular cyclic 3',5'-adenosine monophosphate (cAMP) concentration through Gαs coupling, but interestingly, β2AR antagonists are able to effectively inhibit fibroblast-like synoviocytes (FLSs) proliferation, thus ameliorating experimental RA, indicating that the β2AR signalling pathway is impaired in RA FLSs via unknown mechanisms. The local epinephrine (Epi) level was found to be much higher in inflammatory joints than in normal joints, and high-level stimulation with Epi or isoproterenol (ISO) directly promoted FLSs proliferation and migration due to impaired β2AR signalling and cAMP production. By applying inhibitor of receptor internalization, and small interfering RNA (siRNA) of Gαs and Gαi, and by using fluorescence resonance energy transfer and coimmunoprecipitation assays, a switch in Gαs-Gαi coupling to β2AR was observed in inflammatory FLSs as well as in FLSs with chronic ISO stimulation. This Gαi coupling was then revealed to be initiated by G protein coupled receptor kinase 2 (GRK2) but not β-arrestin2 or protein kinase A-mediated phosphorylation of β2AR. Inhibiting the activity of GRK2 with the novel GRK2 inhibitor paeoniflorin-6'-O-benzene sulfonate (CP-25), a derivative of paeoniflorin, or the accepted GRK2 inhibitor paroxetine effectively reversed the switch in Gαs-Gαi coupling to β2AR during inflammation and restored the intracellular cAMP level in ISO-stimulated FLSs. As expected, CP-25 significantly inhibited the hyperplasia of FLSs in a collagen-induced arthritis (CIA) model (CIA FLSs) and normal FLSs stimulated with ISO and finally ameliorated CIA in rats. Together, our findings revealed the pathological changes in β2AR signalling in CIA FLSs, determined the underlying mechanisms and identified the pharmacological target of the GRK2 inhibitor CP-25 in treating CIA. Video Abstract.
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Affiliation(s)
- Mingli Ge
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Li Wu
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
- Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Feng He
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Yu Tai
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Ruhong Fang
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Dafei Han
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Paipai Guo
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China
| | - Hao Liu
- School of Pharmacy, Bengbu Medical College, Bengbu, 233030, China
| | - Yong Hu
- Department of Orthopaedics, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, China
| | - Shenglin Xu
- Department of Orthopaedics, The First Affiliated Hospital of Anhui Medical University, Hefei, 230032, China.
| | - Wei Wei
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China.
| | - Qingtong Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-Inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-Inflammatory and Immune Medicine, Hefei, 230032, China.
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Matarrese P, Maccari S, Gambardella L, Vona R, Barbagallo F, Vezzi V, Stati T, Grò MC, Giovannetti A, Catalano L, Molinari P, Marano G, Ambrosio C. Benzodiazepine diazepam regulates cell surface β1-adrenergic receptor density in human monocytes. Eur J Pharmacol 2023; 948:175700. [PMID: 37001579 DOI: 10.1016/j.ejphar.2023.175700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023]
Abstract
Downregulation of cell surface β-adrenergic receptors (β-AR) is an important adaptive response that prevents deleterious effects of receptor overstimulation. Various factors including reactive oxygen species cause β-AR downregulation. In this study, we evaluated the effects of ligands of the peripheral benzodiazepine receptor (PBR), a key protein in regulating oxidative stress, on surface density of endogenous β1-and β2-ARs in highly differentiated cells such as human monocytes, which express both β-AR subtypes. β-AR expression in human monocytes was evaluated by flow cytometry, qPCR and western blotting. Monocyte treatment with β-AR agonist isoproterenol did not change surface β1-AR density while downregulating surface β2-AR density. This effect was antagonized by the β-blocker propranolol. An opposite response was observed with benzodiazepine diazepam that led to a time-dependent reduction in β1-AR density. In particular, while no significant downregulation was observed after 3 h of treatment, only 63% of β1-ARs were still present on the cell surface after 48 h of treatment with diazepam at 1 μM. Treatment with the PBR antagonist PK11195, but not with propranolol, antagonized the effects of diazepam. No change in β1-AR-mRNA or protein levels was observed at any time after diazepam treatment. We also found that diazepam did not affect Gs-protein or β-arrestin-2 recruitment for both β-ARs in engineered fibroblasts, further suggesting that diazepam activity on β1-AR density is mediated by PBR. Finally, no sex-related differences were found. Collectively, these results indicate that monocyte β1-ARs are resistant to catecholamine-mediated downregulation and suggest that PBR plays an important role in regulating β1-AR density.
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Pavey G, Snelleksz M, Dean B. A Novel Method to Estimate Levels of Receptors Using an Allosteric Modulator: Focus on Muscarinic M1 Receptor. Methods Mol Biol 2023; 2687:1-13. [PMID: 37464158 DOI: 10.1007/978-1-0716-3307-6_1] [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: 07/20/2023]
Abstract
This chapter outlines some of the general principles that need to be considered when developing a radioligand binding assay to measure the affinity and density of radioligand binding to a receptor in tissue or on cells. In addition it describes an innovative step forward in using radioligand binding assays to measure levels of muscarinic M1 receptors in human postmortem CNS, using both membrane binding and in situ radioligand binding. These examples show how, using receptor-specific allosteric modulators, it is possible to gain an estimate of the density of a single receptor using a radioligand that is not totally specific to the target site of interest. Given there is a growing understanding that there are problems with antibodies not showing specificity to their supposed target protein, well-characterized radioligand binding techniques still provide an important tool when studying receptor density in tissues and cells.
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Affiliation(s)
- Geoffrey Pavey
- The Victorian Brain Bank Network, The Florey Institute for Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Megan Snelleksz
- The Synapse Biology and Cognition Laboratory, The Florey Institute for Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Brian Dean
- The Synapse Biology and Cognition Laboratory, The Florey Institute for Neuroscience and Mental Health, Parkville, VIC, Australia.
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Klussmeier A, Aurich S, Niederstadt L, Wiedenmann B, Grötzinger C. Secretin Receptor as a Target in Gastrointestinal Cancer: Expression Analysis and Ligand Development. Biomedicines 2022; 10:biomedicines10030536. [PMID: 35327338 PMCID: PMC8944975 DOI: 10.3390/biomedicines10030536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 02/01/2023] Open
Abstract
Secretin was originally discovered as a gastrointestinal peptide that stimulates fluid secretion from the pancreas and liver and delays gastric emptying. In disease, a secretin receptor (SCTR) was found to occur as a splice variant in gastrinoma and pancreatic adenocarcinoma. Overexpression of SCTR has been described for gastrinomas, carcinoid tumors of the lung and cholangiocarcinoma. SCTR therefore is considered a candidate target for molecular tumor imaging as well as for peptide receptor radioligand therapy (PRRT) in a number of oncological indications. The aim of this study was to characterize SCTR expression in esophageal and pancreatic cancer, demonstrating for the first time high SCTR overexpression in these tumor types. In total, 65 of 70 pancreatic ductal adenocarcinoma tissues stained strongly positive for SCTR in immunohistochemistry, as did most of the 151 esophageal cancer samples, with minor influence of grading in both entities. In addition, the aim of this study was to further delineate residues in human secretin that are critical for binding to and activation of human SCTR. For a potential development of short and metabolically stable analogs for clinical use, it was intended to probe the peptide for its capacity to incorporate deletions and substitutions without losing its affinity to SCTR. In a systematic approach, a library of 146 secretin variants containing single amino acid substitutions as well as truncations on either end was tested in β-arrestin2-GFP translocation and fluorescent ligand internalization assays employing high-content analysis, in cAMP assays which run in agonist and antagonist mode, and in radioligand binding. The main structural determinants of SCTR binding and activation were localized to the N-terminus, with His1, Asp3 being among the most sensitive positions, followed by Phe6, Thr7 and Leu10. Aminoterminal truncation caused a rapid decline in receptor activity and most of these variants proved to be partial agonists showing antagonistic properties. In this study, the most potent novel antagonist showed an IC50 of 309 ± 74 nM in the β-arrestin2-GFP translocation assay on human SCTR while remaining a weak partial agonist. Future studies will have to demonstrate the utility of further enhanced secretin analogues as tracers for in vivo imaging and therapy.
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Affiliation(s)
- Anja Klussmeier
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany; (A.K.); (S.A.); (L.N.); (B.W.)
- Institut für Chemie und Biochemie, Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, 14195 Berlin, Germany
| | - Stefan Aurich
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany; (A.K.); (S.A.); (L.N.); (B.W.)
| | - Lars Niederstadt
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany; (A.K.); (S.A.); (L.N.); (B.W.)
| | - Bertram Wiedenmann
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany; (A.K.); (S.A.); (L.N.); (B.W.)
| | - Carsten Grötzinger
- Department of Hepatology and Gastroenterology, Charité—Universitätsmedizin Berlin, 13353 Berlin, Germany; (A.K.); (S.A.); (L.N.); (B.W.)
- Partner Site Berlin, German Cancer Consortium (DKTK), 13353 Berlin, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Correspondence:
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Andersen DB, Grunddal KV, Pedersen J, Kuhre RE, Lund ML, Holst JJ, Ørskov C. Using a Reporter Mouse to Map Known and Novel Sites of GLP-1 Receptor Expression in Peripheral Tissues of Male Mice. Endocrinology 2021; 162:6122689. [PMID: 33508122 DOI: 10.1210/endocr/bqaa246] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Indexed: 02/07/2023]
Abstract
Glucagon-like peptide-1 receptor (GLP-1R) activation is used in the treatment of diabetes and obesity; however, GLP-1 induces many other physiological effects with unclear mechanisms of action. To identify the cellular targets of GLP-1 and GLP-1 analogues, we generated a Glp1r.tdTomato reporter mouse expressing the reporter protein, tdTomato, in Glp1r-expressing cells. The reporter signal is expressed in all cells where GLP-1R promoter was ever active. To complement this, we histologically mapped tdTomato-fluorescence, and performed Glp-1r mRNA in situ hybridization and GLP-1R immunohistochemistry on the same tissues. In male mice, we found tdTomato signal in mucus neck, chief, and parietal cells of the stomach; Brunner's glands; small intestinal enteroendocrine cells and intraepithelial lymphocytes; and myenteric plexus nerve fibers throughout the gastrointestinal tract. Pancreatic acinar-, β-, and δ cells, but rarely α cells, were tdTomato-positive, as were renal arteriolar smooth muscle cells; endothelial cells of the liver, portal vein, and endocardium; aortal tunica media; and lung type 1 and type 2 pneumocytes. Some thyroid follicular and parafollicular cells displayed tdTomato expression, as did tracheal cartilage chondrocytes, skin fibroblasts, and sublingual gland mucus cells. In conclusion, our reporter mouse is a powerful tool for mapping known and novel sites of GLP-1R expression in the mouse, thus enhancing our understanding of the many target cells and effects of GLP-1 and GLP-1R agonists.
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Affiliation(s)
- Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kaare V Grunddal
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
| | - Jens Pedersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
- Department of Endocrinology and Nephrology, Nordsjællands Hospital Hillerød, University of Copenhagen, Hillerød, Denmark
| | - Rune E Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mari L Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Copenhagen, Denmark
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Savić B, Martin A, Mecawi AS, Bukumirić Z, Antunes-Rodrigues J, Murphy D, Šarenac O, Japundžić-Žigon N. Vasopressin and v1br gene expression is increased in the hypothalamic pvn of borderline hypertensive rats. Hypertens Res 2020; 43:1165-1174. [PMID: 32415179 DOI: 10.1038/s41440-020-0469-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 12/14/2022]
Abstract
Vasopressin (VP) is a neurohypophyseal peptide best known for its role in maintaining osmotic and cardiovascular homeostasis. The main sources of VP are the supraoptic and paraventricular (PVN) nuclei of the hypothalamus, which coexpress the vasopressin V1a and V1b receptors (V1aR and V1bR). Here, we investigated the level of expression of VP and VP receptors in the PVN of borderline hypertensive rats (BHRs), a key integrative nucleus for neuroendocrine cardiovascular control. Experiments were performed in male BHRs and Wistar rats (WRs) equipped with a radiotelemetry device for continuous hemodynamic recording under baseline conditions and after saline load without or with stress. Autonomic control of the circulation was evaluated by spectral analysis of blood pressure (BP) and heart rate (HR) variability and baroreceptor reflex sensitivity (BRS) using the sequence method. Plasma VP was determined by radioimmunoassay, and VP, V1aR, and V1bR gene expression was determined by RT-qPCR. Under baseline conditions, BHRs had higher BP, lower HR, and stronger BRS than WRs. BP and HR variability was unchanged. In the PVN, overexpression of the VP and V1bR genes was found, and plasma VP was increased. Saline load downregulated V1bR mRNA expression without affecting VP mRNA expression or plasma VP and BP. Adding stress increased BP, HR, and low-frequency sympathetic spectral markers and decreased plasma VP without altering the level of expression of VP and VP receptors in the PVN. It follows that overexpression of VP and V1bR in the PVN is a characteristic trait of BHRs and that sympathetic hyperactivity underlies stress-induced hypertension.
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Affiliation(s)
- Bojana Savić
- Faculty of Medicine, Institute of Pharmacology, Clinical Pharmacology and Toxicology, University of Belgrade, Belgrade, Serbia
| | - Andrew Martin
- Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, BS1 3NY, UK
| | - Andre Souza Mecawi
- Paulista Medical School, Department of Biophysics, Laboratory of Neuroendocrinology, Federal University of São Paulo, São Paulo, Brazil
| | - Zoran Bukumirić
- Faculty of Medicine, Institute for Medical Statics and Informatics, University of Belgrade, Belgrade, Serbia
| | - José Antunes-Rodrigues
- Faculty of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - David Murphy
- Bristol Medical School: Translational Health Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol, BS1 3NY, UK
| | - Olivera Šarenac
- Faculty of Medicine, Institute of Pharmacology, Clinical Pharmacology and Toxicology, University of Belgrade, Belgrade, Serbia
| | - Nina Japundžić-Žigon
- Faculty of Medicine, Institute of Pharmacology, Clinical Pharmacology and Toxicology, University of Belgrade, Belgrade, Serbia.
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Tao YX. Molecular chaperones and G protein-coupled receptor maturation and pharmacology. Mol Cell Endocrinol 2020; 511:110862. [PMID: 32389798 DOI: 10.1016/j.mce.2020.110862] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/15/2022]
Abstract
G protein-coupled receptors (GPCRs) are highly conserved versatile signaling molecules located at the plasma membrane that respond to diverse extracellular signals. They regulate almost all physiological processes in the vertebrates. About 35% of current drugs target these receptors. Mutations in these genes have been identified as causes of numerous diseases. The seven transmembrane domain structure of GPCRs implies that the folding of these transmembrane proteins is extremely complicated and difficult. Indeed, many wild type GPCRs are not folded optimally. The most common defect in genetic diseases caused by GPCR mutations is misfolding and failure to reach the plasma membrane where it functions. General molecular chaperones aid the folding of all proteins, including GPCRs, by preventing aggregation, promoting folding and disaggregating small aggregates. Some GPCRs need additional receptor-specific chaperones to assist their folding. Many of these receptor-specific chaperones interact with additional receptors and alter receptor pharmacology, expanding the understanding of these chaperone proteins.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, 36849-5519, USA.
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8
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Chiu ML, Goulet DR, Teplyakov A, Gilliland GL. Antibody Structure and Function: The Basis for Engineering Therapeutics. Antibodies (Basel) 2019; 8:antib8040055. [PMID: 31816964 PMCID: PMC6963682 DOI: 10.3390/antib8040055] [Citation(s) in RCA: 242] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022] Open
Abstract
Antibodies and antibody-derived macromolecules have established themselves as the mainstay in protein-based therapeutic molecules (biologics). Our knowledge of the structure–function relationships of antibodies provides a platform for protein engineering that has been exploited to generate a wide range of biologics for a host of therapeutic indications. In this review, our basic understanding of the antibody structure is described along with how that knowledge has leveraged the engineering of antibody and antibody-related therapeutics having the appropriate antigen affinity, effector function, and biophysical properties. The platforms examined include the development of antibodies, antibody fragments, bispecific antibody, and antibody fusion products, whose efficacy and manufacturability can be improved via humanization, affinity modulation, and stability enhancement. We also review the design and selection of binding arms, and avidity modulation. Different strategies of preparing bispecific and multispecific molecules for an array of therapeutic applications are included.
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Affiliation(s)
- Mark L. Chiu
- Drug Product Development Science, Janssen Research & Development, LLC, Malvern, PA 19355, USA
- Correspondence:
| | - Dennis R. Goulet
- Department of Medicinal Chemistry, University of Washington, P.O. Box 357610, Seattle, WA 98195-7610, USA;
| | - Alexey Teplyakov
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
| | - Gary L. Gilliland
- Biologics Research, Janssen Research & Development, LLC, Spring House, PA 19477, USA; (A.T.); (G.L.G.)
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Hamlett ED, Ledreux A, Gilmore A, Vazey EM, Aston-Jones G, Boger HA, Paredes D, Granholm ACE. Inhibitory designer receptors aggravate memory loss in a mouse model of down syndrome. Neurobiol Dis 2019; 134:104616. [PMID: 31678403 DOI: 10.1016/j.nbd.2019.104616] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/06/2019] [Accepted: 09/17/2019] [Indexed: 12/20/2022] Open
Abstract
The pontine nucleus locus coeruleus (LC) is the primary source of noradrenergic (NE) projections to the brain and is important for working memory, attention, and cognitive flexibility. Individuals with Down syndrome (DS) develop Alzheimer's disease (AD) with high penetrance and often exhibit working memory deficits coupled with degeneration of LC-NE neurons early in the progression of AD pathology. Designer receptors exclusively activated by designer drugs (DREADDs) are chemogenetic tools that allow targeted manipulation of discrete neuronal populations in the brain without the confounds of off-target effects. We utilized male Ts65Dn mice (a mouse model for DS), and male normosomic (NS) controls to examine the effects of inhibitory DREADDs delivered via an AAV vector under translational control of the synthetic PRSx8, dopamine β hydroxylase (DβH) promoter. This chemogenetic tool allowed LC inhibition upon administration of the inert DREADD ligand, clozapine-N-oxide (CNO). DREADD-mediated LC inhibition impaired performance in a novel object recognition task and reversal learning in a spatial task. DREADD-mediated LC inhibition gave rise to an elevation of α-adrenoreceptors both in NS and in Ts65Dn mice. Further, microglial markers showed that the inhibitory DREADD stimulation led to increased microglial activation in the hippocampus in Ts65Dn but not in NS mice. These findings strongly suggest that LC signaling is important for intact memory and learning in Ts65Dn mice and disruption of these neurons leads to increased inflammation and dysregulation of adrenergic receptors.
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Affiliation(s)
- Eric D Hamlett
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, USA.
| | - Aurélie Ledreux
- Knoebel Institute for Healthy Aging, University of Denver, Denver, CO 80208, USA
| | - Anah Gilmore
- Knoebel Institute for Healthy Aging, University of Denver, Denver, CO 80208, USA
| | - Elena M Vazey
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Gary Aston-Jones
- Rutgers Brain Health Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Heather A Boger
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Daniel Paredes
- Knoebel Institute for Healthy Aging, University of Denver, Denver, CO 80208, USA
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Brunner SM, Koller A, Stockinger J, Sternberg F, Leis S, Ernst F, Strasser P, Brodowicz B, Ebner S, Holub BS, Rauch I, Graf K, Lang R, Kofler B. Validation of antibody-based tools for galanin research. Peptides 2019; 120:170009. [PMID: 30196126 DOI: 10.1016/j.peptides.2018.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/02/2018] [Accepted: 08/22/2018] [Indexed: 12/17/2022]
Abstract
Antibodies are an integral biomedical tool, not only for research but also as therapeutic agents. However, progress can only be made with sensitive and specific antibodies. The regulatory (neuro)peptide galanin and its three endogenous receptors (GAL1-3-R) are widely distributed in the central and peripheral nervous systems, and in peripheral non-neuronal tissues. The galanin system has multiple biological functions, including feeding behavior, pain processing, nerve regeneration and inflammation, to name only a few. Galanin could serve as biomarker in these processes, and therefore its receptors are potential drug targets for various diseases. For that reason, it is of paramount interest to precisely measure galanin peptide levels in tissues and to determine the cellular and subcellular localization of galanin receptors. A plethora of antibodies and antibody-based tools, including radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) kits, are commercially available to detect galanin and its receptors. However, many of them lack rigorous validation which casts doubt on their specificity. A goal of the present study was to raise awareness of the importance of validation of antibodies and antibody-based tools, with a specific focus on the galanin system. To that end, we tested and report here about commercially available antibodies against galanin and galanin receptors that appear specific to us. Furthermore, we investigated the validity of commercially available galanin ELISA kits. As the tested ELISAs failed to meet the validation requirements, we developed and validated a specific sandwich ELISA which can be used to detect full-length galanin in human plasma.
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Affiliation(s)
- Susanne M Brunner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Andreas Koller
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Julia Stockinger
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Felix Sternberg
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Stefan Leis
- Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, University Hospital of the Paracelsus Medical University, Ignaz-Harrer-Straße 79, 5020, Salzburg, Austria.
| | - Florian Ernst
- Department of Neurology, Christian Doppler Medical Centre and Centre for Cognitive Neuroscience, University Hospital of the Paracelsus Medical University, Ignaz-Harrer-Straße 79, 5020, Salzburg, Austria.
| | - Peter Strasser
- University Institute for Medical & Chemical Laboratory Diagnostic, University Hospital of the Paracelsus Medical University, Ignaz-Harrer-Straße 79, 5020, Salzburg, Austria.
| | - Bernhard Brodowicz
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Sabine Ebner
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Barbara S Holub
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Isabella Rauch
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Kerstin Graf
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Roland Lang
- Department of Dermatology, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
| | - Barbara Kofler
- Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, University Hospital of the Paracelsus Medical University, Muellner Hauptstraße 48, 5020, Salzburg, Austria.
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11
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Knudsen LB, Lau J. The Discovery and Development of Liraglutide and Semaglutide. Front Endocrinol (Lausanne) 2019; 10:155. [PMID: 31031702 PMCID: PMC6474072 DOI: 10.3389/fendo.2019.00155] [Citation(s) in RCA: 397] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 02/21/2019] [Indexed: 12/12/2022] Open
Abstract
The discovery of glucagon-like peptide-1 (GLP-1), an incretin hormone with important effects on glycemic control and body weight regulation, led to efforts to extend its half-life and make it therapeutically effective in people with type 2 diabetes (T2D). The development of short- and then long-acting GLP-1 receptor agonists (GLP-1RAs) followed. Our article charts the discovery and development of the long-acting GLP-1 analogs liraglutide and, subsequently, semaglutide. We examine the chemistry employed in designing liraglutide and semaglutide, the human and non-human studies used to investigate their cellular targets and pharmacological effects, and ongoing investigations into new applications and formulations of these drugs. Reversible binding to albumin was used for the systemic protraction of liraglutide and semaglutide, with optimal fatty acid and linker combinations identified to maximize albumin binding while maintaining GLP-1 receptor (GLP-1R) potency. GLP-1RAs mediate their effects via this receptor, which is expressed in the pancreas, gastrointestinal tract, heart, lungs, kidneys, and brain. GLP-1Rs in the pancreas and brain have been shown to account for the respective improvements in glycemic control and body weight that are evident with liraglutide and semaglutide. Both liraglutide and semaglutide also positively affect cardiovascular (CV) outcomes in individuals with T2D, although the precise mechanism is still being explored. Significant weight loss, through an effect to reduce energy intake, led to the approval of liraglutide (3.0 mg) for the treatment of obesity, an indication currently under investigation with semaglutide. Other ongoing investigations with semaglutide include the treatment of non-alcoholic fatty liver disease (NASH) and its use in an oral formulation for the treatment of T2D. In summary, rational design has led to the development of two long-acting GLP-1 analogs, liraglutide and semaglutide, that have made a vast contribution to the management of T2D in terms of improvements in glycemic control, body weight, blood pressure, lipids, beta-cell function, and CV outcomes. Furthermore, the development of an oral formulation for semaglutide may provide individuals with additional benefits in relation to treatment adherence. In addition to T2D, liraglutide is used in the treatment of obesity, while semaglutide is currently under investigation for use in obesity and NASH.
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Affiliation(s)
- Lotte Bjerre Knudsen
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
- *Correspondence: Lotte Bjerre Knudsen
| | - Jesper Lau
- Global Research Technology, Novo Nordisk A/S, Måløv, Denmark
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12
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Bird MF, Guerrini R, Willets JM, Thompson JP, Caló G, Lambert DG. Nociceptin/Orphanin FQ (N/OFQ) conjugated to ATTO594: a novel fluorescent probe for the N/OFQ (NOP) receptor. Br J Pharmacol 2018; 175:4496-4506. [PMID: 30276802 PMCID: PMC6255954 DOI: 10.1111/bph.14504] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/31/2018] [Accepted: 09/04/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE The nociceptin/orphanin FQ (N/OFQ) receptor (NOP) is a member of the opioid receptor family and is involved in a number of physiological responses, pain and immune regulation as examples. In this study, we conjugated a red fluorophore-ATTO594 to the peptide ligand N/OFQ (N/OFQATTO594 ) for the NOP receptor and explored NOP receptor function at high (in recombinant systems) and low (on immune cells) expression. EXPERIMENTAL APPROACH We assessed N/OFQATTO594 receptor binding, selectivity and functional activity in recombinant (CHO) cell lines. Live cell N/OFQATTO594 binding was measured in (i) HEK cells expressing NOP and NOPGFP receptors, (ii) CHO cells expressing the hNOPGαqi5 chimera (to force coupling to measurable Ca2+ responses) and (iii) freshly isolated human polymorphonuclear cells (PMN). KEY RESULTS N/OFQATTO594 bound to NOP receptor with nM affinity and high selectivity. N/OFQATTO594 activated NOP receptor by reducing cAMP formation and increasing Ca2+ levels in CHOhNOPGαqi5 cells. N/OFQATTO594 was also able to visualize NOP receptors at low expression levels on PMN cells. In NOP-GFP-tagged receptors, N/OFQATTO594 was used in a FRET protocol where GFP emission activated ATTO, visualizing ligand-receptor interaction. When the NOPGFP receptor is activated by N/OFQATTO594 , movement of ligand and receptor from the cell surface to the cytosol can be measured. CONCLUSIONS AND IMPLICATIONS In the absence of validated NOP receptor antibodies and issues surrounding the use of radiolabels (especially in low expression systems), these data indicate the utility of N/OFQATTO594 to study a wide range of N/OFQ-driven cellular responses.
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Affiliation(s)
- M F Bird
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
| | - R Guerrini
- Department of Chemical and Pharmaceutical Sciences and LTTAUniversity of FerraraFerraraItaly
| | - J M Willets
- Department of Molecular and Cell BiologyUniversity of LeicesterLeicesterUK
| | - J P Thompson
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
| | - G Caló
- Department of Medical Sciences, Section of Pharmacology and National Institute of NeuroscienceUniversity of FerraraFerraraItaly
| | - D G Lambert
- Department of Cardiovascular Sciences, Anaesthesia, Critical Care and Pain Management, Leicester Royal InfirmaryUniversity of LeicesterLeicesterUK
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13
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Hebsgaard JB, Pyke C, Yildirim E, Knudsen LB, Heegaard S, Kvist PH. Glucagon-like peptide-1 receptor expression in the human eye. Diabetes Obes Metab 2018; 20:2304-2308. [PMID: 29707863 PMCID: PMC6099507 DOI: 10.1111/dom.13339] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/13/2018] [Accepted: 04/23/2018] [Indexed: 12/20/2022]
Abstract
Semaglutide is a human glucagon-like peptide-1 (GLP-1) analogue that is in development for the treatment of type 2 diabetes. In the pre-approval cardiovascular outcomes trial SUSTAIN 6, semaglutide was associated with a significant increase in the risk of diabetic retinopathy (DR) complications vs placebo. GLP-1 receptor (GLP-1R) expression has previously been demonstrated in the retina in animals and humans; however, antibodies used to detect expression have been documented to be non-specific and fail to detect the GLP-1R using immunohistochemistry (IHC), a problem common for many G-protein coupled receptors. Using a validated GLP-1R antibody for IHC and in situ hybridization for GLP-1R mRNA in normal human eyes, GLP-1Rs were detected in a small fraction of neurons in the ganglion cell layer. In advanced stages of DR, GLP-1R expression was not detected at the protein or mRNA level. Specifically, no GLP-1R expression was found in the eyes of people with long-standing proliferative DR (PDR). In conclusion, GLP-1R expression is low in normal human eyes and was not detected in eyes exhibiting advanced stages of PDR.
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Affiliation(s)
| | | | | | | | - Steffen Heegaard
- Department of Pathology, Rigshospitalet, Eye Pathology SectionUniversity of CopenhagenCopenhagenDenmark
- Department of Ophthalmology, RigshospitaletUniversity of CopenhagenCopenhagenDenmark
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14
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Park M, Steinberg SF. Carvedilol Prevents Redox Inactivation of Cardiomyocyte Β 1-Adrenergic Receptors. JACC Basic Transl Sci 2018; 3:521-532. [PMID: 30175276 PMCID: PMC6116783 DOI: 10.1016/j.jacbts.2018.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 01/14/2023]
Abstract
The mechanism that leads to a decrease in β1-adrenergic receptor (β1AR) expression in the failing heart remains uncertain. This study shows that cardiomyocyte β1AR expression and isoproterenol responsiveness decrease in response to oxidative stress. Studies of mechanisms show that the redox-dependent decrease in β1AR expression is uniquely prevented by carvedilol and not other βAR ligands. Carvedilol also promotes the accumulation of N-terminally truncated β1ARs that confer protection against doxorubicin-induced apoptosis in association with activation of protein kinase B. The redox-induced molecular controls for cardiomyocyte β1ARs and pharmacologic properties of carvedilol identified in this study have important clinical and therapeutic implications.
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Key Words
- AKT
- AKT, protein kinase B
- CREB, cyclic adenosine monophosphate binding response element protein
- ERK, extracellular regulated kinase
- FL, full-length
- GFX, GF109203X
- GRK, G protein–coupled receptor kinase
- HF, heart failure
- PKA, protein kinase A
- PKC, protein kinase C
- PTX, pertussis toxin
- ROS, reactive oxygen species
- cAMP, cyclic adenosine monophosphate
- cardiomyocytes
- cardioprotection
- oxidant stress
- β1-adrenergic receptor
- βAR, β-adrenergic receptor
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Affiliation(s)
- Misun Park
- Department of Pharmacology, Columbia University, New York, New York
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15
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Mirabegron, a β 3-adrenoceptor agonist reduced platelet aggregation through cyclic adenosine monophosphate accumulation. Eur J Pharmacol 2018; 829:79-84. [PMID: 29654782 DOI: 10.1016/j.ejphar.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 04/05/2018] [Accepted: 04/09/2018] [Indexed: 11/22/2022]
Abstract
Mirabegron is a β3-adrenoceptor agonist and released on the marked for the treatment of overactive bladder. Because mirabegron is the only β3-adrenoceptor agonist available and substances that increase the levels of cyclic adenosine monophosphate (cAMP) inhibit platelet activity, we tested the hypothesis that mirabegron could have antiplatelet activity. Collagen- and thrombin induced platelet aggregation, thromboxane B2 (TXB2) and cyclic nucleotides quantification and calcium (Ca2+) mobilization were determined in the absence and presence of mirabegron in human washed platelets. Our results revealed that mirabegron (10-300 µM) produced significant inhibitions on platelet aggregation induced by collagen- or thrombin, accompanied by greater intracellular levels of cAMP. The β3-adrenoceptor antagonist L 748,337 (1 µM) and the adenylate cyclase inhibitor, SQ 22,536 (100 µM) reversed the inhibition induced by mirabegron in thrombin-stimulated platelets. The selective antagonists for β1-and β2-adrenoceptors, atenolol and ICI 117,551 (3 µM), respectively did not interfere on the inhibition induced by mirabegron. In Fluo-4 loaded platelets, mirabegron reduced the total and intracellular Ca2+ levels. Pre-incubation with mirabegron almost abolished the levels of TXB2. Mirabegron did not augment the intracellular levels of cyclic guanosine monophosphate. In conclusion, mirabegron inhibited human platelet aggregation through cAMP accumulation, thus suggesting that substances that activate β3-adrenoceptor could be beneficial as adjuvant antiplatelet therapy.
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16
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Burghi V, Fernández NC, Gándola YB, Piazza VG, Quiroga DT, Guilhen Mario É, Felix Braga J, Bader M, Santos RAS, Dominici FP, Muñoz MC. Validation of commercial Mas receptor antibodies for utilization in Western Blotting, immunofluorescence and immunohistochemistry studies. PLoS One 2017; 12:e0183278. [PMID: 28813513 PMCID: PMC5558983 DOI: 10.1371/journal.pone.0183278] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/01/2017] [Indexed: 12/16/2022] Open
Abstract
Mas receptor (MasR) is a G protein-coupled receptor proposed as a candidate for mediating the angiotensin (Ang)-converting enzyme 2-Ang (1-7) protective axis of renin-angiotensin system. Because the role of this receptor is not definitively clarified, determination of MasR tissue distribution and expression levels constitutes a critical knowledge to fully understanding its function. Commercially available antibodies have been widely employed for MasR protein localization and quantification, but they have not been adequately validated. In this study, we carried on an exhaustive evaluation of four commercial MasR antibodies, following previously established criteria. Western Blotting (WB) and immunohistochemistry studies starting from hearts and kidneys from wild type (WT) mice revealed that antibodies raised against different MasR domains yielded different patterns of reactivity. Furthermore, staining patterns appeared identical in samples from MasR knockout (MasR-KO) mice. We verified by polymerase chain reaction analysis that the MasR-KO mice used were truly deficient in this receptor as MAS transcripts were undetectable in either heart or kidney from this animal model. In addition, we evaluated the ability of the antibodies to detect the human c-myc-tagged MasR overexpressed in human embryonic kidney cells. Three antibodies were capable of detecting the MasR either by WB or by immunofluorescence, reproducing the patterns obtained with an anti c-myc antibody. In conclusion, although three of the selected antibodies were able to detect MasR protein at high expression levels observed in a transfected cell line, they failed to detect this receptor in mice tissues at physiological expression levels. As a consequence, validated antibodies that can recognize and detect the MasR at physiological levels are still lacking.
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Affiliation(s)
- Valeria Burghi
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Natalia Cristina Fernández
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Investigaciones Farmacológicas (ININFA), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Yamila Belén Gándola
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Verónica Gabriela Piazza
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Diego Tomás Quiroga
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Érica Guilhen Mario
- INCT-NanoBiofar, Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Janaína Felix Braga
- INCT-NanoBiofar, Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Michael Bader
- Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Robson Augusto Souza Santos
- INCT-NanoBiofar, Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Cardiology Institute of Rio Grande do Sul/University Foundation of Cardiology (IC/FUC), Porto Alegre, Rio Grande do Sul, Brazil
| | - Fernando Pablo Dominici
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Marina Cecilia Muñoz
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas (IQUIFIB), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
- * E-mail:
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17
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Park M, Reddy GR, Wallukat G, Xiang YK, Steinberg SF. β 1-adrenergic receptor O-glycosylation regulates N-terminal cleavage and signaling responses in cardiomyocytes. Sci Rep 2017; 7:7890. [PMID: 28801655 PMCID: PMC5554155 DOI: 10.1038/s41598-017-06607-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 06/15/2017] [Indexed: 11/09/2022] Open
Abstract
β1-adrenergic receptors (β1ARs) mediate catecholamine actions in cardiomyocytes by coupling to both Gs/cAMP-dependent and Gs-independent/growth-regulatory pathways. Structural studies of the β1AR define ligand-binding sites in the transmembrane helices and effector docking sites at the intracellular surface of the β1AR, but the extracellular N-terminus, which is a target for post-translational modifications, typically is ignored. This study identifies β1AR N-terminal O-glycosylation at Ser37/Ser41 as a mechanism that prevents β1AR N-terminal cleavage. We used an adenoviral overexpression strategy to show that both full-length/glycosylated β1ARs and N-terminally truncated glycosylation-defective β1ARs couple to cAMP and ERK-MAPK signaling pathways in cardiomyocytes. However, a glycosylation defect that results in N-terminal truncation stabilizes β1ARs in a conformation that is biased toward the cAMP pathway. The identification of O-glycosylation and N-terminal cleavage as novel structural determinants of β1AR responsiveness in cardiomyocytes could be exploited for therapeutic advantage.
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Affiliation(s)
- Misun Park
- Department of Pharmacology, Columbia University, New York, NY, USA
| | - Gopireddy R Reddy
- Department of Pharmacology, University of California at Davis, Davis, CA, USA
| | - Gerd Wallukat
- Experimental and Clinical Research Center, Charité Campus Buch and Max-Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Yang K Xiang
- Department of Pharmacology, University of California at Davis, Davis, CA, USA.,VA Northern California Health Care System, Mather, CA, USA
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18
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Koenig P, Sanowar S, Lee CV, Fuh G. Tuning the specificity of a Two-in-One Fab against three angiogenic antigens by fully utilizing the information of deep mutational scanning. MAbs 2017; 9:959-967. [PMID: 28585908 PMCID: PMC5540083 DOI: 10.1080/19420862.2017.1337618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/24/2017] [Accepted: 05/27/2017] [Indexed: 10/19/2022] Open
Abstract
Monoclonal antibodies developed for therapeutic or diagnostic purposes need to demonstrate highly defined binding specificity profiles. Engineering of an antibody to enhance or reduce binding to related antigens is often needed to achieve the desired biologic activity without safety concern. Here, we describe a deep sequencing-aided engineering strategy to fine-tune the specificity of an angiopoietin-2 (Ang2)/vascular endothelial growth factor (VEGF) dual action Fab, 5A12.1 for the treatment of age-related macular degeneration. This antibody utilizes overlapping complementarity-determining region (CDR) sites for dual Ang2/VEGF interaction with KD in the sub-nanomolar range. However, it also exhibits significant (KD of 4 nM) binding to angiopoietin-1, which has high sequence identity with Ang2. We generated a large phage-displayed library of 5A12.1 Fab variants with all possible single mutations in the 6 CDRs. By tracking the change of prevalence of each mutation during various selection conditions, we identified 35 mutations predicted to decrease the affinity for Ang1 while maintaining the affinity for Ang2 and VEGF. We confirmed the specificity profiles for 25 of these single mutations as Fab protein. Structural analysis showed that some of the Fab mutations cluster near a potential Ang1/2 epitope residue that differs in the 2 proteins, while others are up to 15 Å away from the antigen-binding site and likely influence the binding interaction remotely. The approach presented here provides a robust and efficient method for specificity engineering that does not require prior knowledge of the antigen antibody interaction and can be broadly applied to antibody specificity engineering projects.
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Affiliation(s)
- Patrick Koenig
- Department of Antibody Engineering, Genentech Inc., South San Francisco, CA, USA
| | - Sarah Sanowar
- Department of Antibody Engineering, Genentech Inc., South San Francisco, CA, USA
| | - Chingwei V. Lee
- Department of Antibody Engineering, Genentech Inc., South San Francisco, CA, USA
| | - Germaine Fuh
- Department of Antibody Engineering, Genentech Inc., South San Francisco, CA, USA
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19
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Myagmar BE, Flynn JM, Cowley PM, Swigart PM, Montgomery MD, Thai K, Nair D, Gupta R, Deng DX, Hosoda C, Melov S, Baker AJ, Simpson PC. Adrenergic Receptors in Individual Ventricular Myocytes: The Beta-1 and Alpha-1B Are in All Cells, the Alpha-1A Is in a Subpopulation, and the Beta-2 and Beta-3 Are Mostly Absent. Circ Res 2017; 120:1103-1115. [PMID: 28219977 DOI: 10.1161/circresaha.117.310520] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Revised: 02/13/2017] [Accepted: 02/17/2017] [Indexed: 12/20/2022]
Abstract
RATIONALE It is unknown whether every ventricular myocyte expresses all 5 of the cardiac adrenergic receptors (ARs), β1, β2, β3, α1A, and α1B. The β1 and β2 are thought to be the dominant myocyte ARs. OBJECTIVE Quantify the 5 cardiac ARs in individual ventricular myocytes. METHODS AND RESULTS We studied ventricular myocytes from wild-type mice, mice with α1A and α1B knockin reporters, and β1 and β2 knockout mice. Using individual isolated cells, we measured knockin reporters, mRNAs, signaling (phosphorylation of extracellular signal-regulated kinase and phospholamban), and contraction. We found that the β1 and α1B were present in all myocytes. The α1A was present in 60%, with high levels in 20%. The β2 and β3 were detected in only ≈5% of myocytes, mostly in different cells. In intact heart, 30% of total β-ARs were β2 and 20% were β3, both mainly in nonmyocytes. CONCLUSION The dominant ventricular myocyte ARs present in all cells are the β1 and α1B. The β2 and β3 are mostly absent in myocytes but are abundant in nonmyocytes. The α1A is in just over half of cells, but only 20% have high levels. Four distinct myocyte AR phenotypes are defined: 30% of cells with β1 and α1B only; 60% that also have the α1A; and 5% each that also have the β2 or β3. The results raise cautions in experimental design, such as receptor overexpression in myocytes that do not express the AR normally. The data suggest new paradigms in cardiac adrenergic signaling mechanisms.
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Affiliation(s)
- Bat-Erdene Myagmar
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - James M Flynn
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Patrick M Cowley
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Philip M Swigart
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Megan D Montgomery
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Kevin Thai
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Divya Nair
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Rumita Gupta
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - David X Deng
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Chihiro Hosoda
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Simon Melov
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Anthony J Baker
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.)
| | - Paul C Simpson
- From the Department of Medicine, VA Medical Center, San Francisco, CA (B.-E.M., P.M.C., P.M.S., M.D.M., K.T., D.N., R.G., D.X.D., C.H., A.J.B., P.C.S.); Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco (B.-E.M., P.M.C., M.D.M., D.X.D., C.H., A.J.B., P.C.S.); and Buck Institute for Research on Aging, Novato, CA (J.M.F., S.M.).
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20
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Beta-adrenergic antagonist propranolol inhibits mammalian cell lysosome spreading and invasion by Trypanosoma cruzi metacyclic forms. Microbes Infect 2017; 19:295-301. [PMID: 28111357 DOI: 10.1016/j.micinf.2017.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 11/23/2022]
Abstract
The involvement of β-adrenergic receptor (β-AR) in host cell invasion by Trypanosoma cruzi metacyclic trypomastigote (MT) is not known. We examined whether isoproterenol, an agonist of β-AR, or nonselective β-blocker propranolol affected MT internalization mediated the stage-specific surface molecule gp82. Treatment of HeLa cells with propranolol significantly inhibited MT invasion whereas isoproterenol had no effect. Propranolol, but not isoproterenol, also inhibited the lysosome spreading required for gp82-dependent MT invasion. The effect of propranolol in inhibiting MT internalization was not due to the prevention of gp82 interaction with β-AR. It was mainly associated with its ability to impair lysosome spreading.
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21
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Danbolt NC, Zhou Y, Furness DN, Holmseth S. Strategies for immunohistochemical protein localization using antibodies: What did we learn from neurotransmitter transporters in glial cells and neurons. Glia 2016; 64:2045-2064. [PMID: 27458697 DOI: 10.1002/glia.23027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 06/19/2016] [Accepted: 06/21/2016] [Indexed: 12/11/2022]
Abstract
Immunocytochemistry and Western blotting are still major methods for protein localization, but they rely on the specificity of the antibodies. Validation of antibody specificity remains challenging mostly because ideal negative controls are often unavailable. Further, immunochemical labeling patterns are also influenced by a number of other factors such as postmortem changes, fixation procedures and blocking agents as well as the general assay conditions (e.g., buffers, temperature, etc.). Western blotting similarly depends on tissue collection and sample preparation as well as the electrophoretic separation, transfer to blotting membranes and the immunochemical probing of immobilized molecules. Publication of inaccurate information on protein distribution has downstream consequences for other researchers because the interpretation of physiological and pharmacological observations depends on information on where ion channels, receptors, enzymes or transporters are located. Despite numerous reports, some of which are strongly worded, erroneous localization data are being published. Here we describe the extent of the problem and illustrate the nature of the pitfalls with examples from studies of neurotransmitter transporters. We explain the importance of supplementing immunochemical observations with other measurements (e.g., mRNA levels and distribution, protein activity, mass spectrometry, electrophysiological recordings, etc.) and why quantitative considerations are integral parts of the quality control. Further, we propose a practical strategy for researchers who plan to embark on a localization study. We also share our thoughts about guidelines for quality control. GLIA 2016;64:2045-2064.
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Affiliation(s)
- Niels Christian Danbolt
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
| | - Yun Zhou
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - David N Furness
- School of Life Sciences, Keele University, Keele, Staffs, United Kingdom
| | - Silvia Holmseth
- Neurotransporter Group, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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22
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Linares A, Couling LE, Carrera EJ, Speth RC. Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors. J Vis Exp 2016. [PMID: 27341008 DOI: 10.3791/53866] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
This protocol describes receptor binding patterns for Angiotensin II (Ang II) in the rat brain using a radioligand specific for Ang II receptors to perform receptor autoradiographic mapping. Tissue specimens are harvested and stored at -80 °C. A cryostat is used to coronally section the tissue (brain) and thaw-mount the sections onto charged slides. The slide-mounted tissue sections are incubated in (125)I-SI-Ang II to radiolabel Ang II receptors. Adjacent slides are separated into two sets: 'non-specific binding' (NSP) in the presence of a receptor saturating concentration of non-radiolabeled Ang II, or an AT1 Ang II receptor subtype (AT1R) selective Ang II receptor antagonist, and 'total binding' with no AT1R antagonist. A saturating concentration of AT2 Ang II receptor subtype (AT2R) antagonist (PD123319, 10 µM) is also present in the incubation buffer to limit (125)I-SI-Ang II binding to the AT1R subtype. During a 30 min pre-incubation at ~22 °C, NSP slides are exposed to 10 µM PD123319 and losartan, while 'total binding' slides are exposed to 10 µM PD123319. Slides are then incubated with (125)I-SI-Ang II in the presence of PD123319 for 'total binding', and PD123319 and losartan for NSP in assay buffer, followed by several 'washes' in buffer, and water to remove salt and non-specifically bound radioligand. The slides are dried using blow-dryers, then exposed to autoradiography film using a specialized film and cassette. The film is developed and the images are scanned into a computer for visual and quantitative densitometry using a proprietary imaging system and a spreadsheet. An additional set of slides are thionin-stained for histological comparisons. The advantage of using receptor autoradiography is the ability to visualize Ang II receptors in situ, within a section of a tissue specimen, and anatomically identify the region of the tissue by comparing it to an adjacent histological reference section.
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Affiliation(s)
- Andrea Linares
- Farquhar College of Arts and Sciences, Nova Southeastern University
| | - Leena E Couling
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University
| | | | - Robert C Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University;
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23
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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: 49] [Impact Index Per Article: 6.1] [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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24
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Tripathi A, Gaponenko V, Majetschak M. Commercially available antibodies directed against α-adrenergic receptor subtypes and other G protein-coupled receptors with acceptable selectivity in flow cytometry experiments. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2015; 389:243-8. [PMID: 26660071 DOI: 10.1007/s00210-015-1196-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/02/2015] [Indexed: 11/26/2022]
Abstract
Several previous reports suggested that many commercially available antibodies directed against G protein-coupled receptors (GPCR) lack sufficient selectivity. Accordingly, it has been proposed that receptor antibodies should be validated by at least one of several criteria, such as testing tissues or cells after knockout or silencing of the corresponding gene. Here, we tested whether 12 commercially available antibodies directed against α-adrenergic receptor (AR) subtypes (α1A/B/D, α2A/B/C), atypical chemokine receptor 3 (ACKR3), and vasopressin receptor 1A (AVPR1A) suffice these criteria. We detected in flow cytometry experiments with human vascular smooth muscle cells that the fluorescence signals from each of these antibodies were reduced by 46 ± 10 %-91 ± 2 % in cells treated with commercially available small interfering RNA (siRNA) specific for each receptor, as compared with cells that were incubated with non-targeting siRNA. The tested antibodies included anti-ACKR3 (R&D Systems, mab42273), for which specificity has previously been demonstrated. Staining with this antibody resulted in 72 ± 5 % reduction of the fluorescence signal after ACKR3 siRNA treatment. Furthermore, staining with anti-α1A-AR (Santa Cruz, sc1477) and anti-ACKR3 (Abcam, ab38089), which have previously been reported to be non-specific, resulted in 70 ± 19 % and 80 ± 4 % loss of the fluorescence signal after α1A-AR and ACKR3 siRNA treatment, respectively. Our findings demonstrate that the tested antibodies show reasonable selectivity for their receptor target under our experimental conditions. Furthermore, our observations suggest that the selectivity of GPCR antibodies depends on the method for which the antibody is employed, the species from which cells/tissues are obtained, and on the type of specimens (cell, tissue/cell homogenate, or section) tested.
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MESH Headings
- Antibodies/immunology
- Antibodies/metabolism
- Antibody Specificity
- Antigen-Antibody Complex/immunology
- Antigen-Antibody Complex/metabolism
- Binding Sites, Antibody
- Cells, Cultured
- Flow Cytometry/methods
- Humans
- Muscle, Smooth, Vascular/immunology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/immunology
- Myocytes, Smooth Muscle/metabolism
- Protein Binding
- RNA Interference
- Receptors, Adrenergic, alpha/genetics
- Receptors, Adrenergic, alpha/immunology
- Receptors, Adrenergic, alpha/metabolism
- Receptors, CXCR/genetics
- Receptors, CXCR/immunology
- Receptors, CXCR/metabolism
- Receptors, Vasopressin/genetics
- Receptors, Vasopressin/immunology
- Receptors, Vasopressin/metabolism
- Transfection
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Affiliation(s)
- Abhishek Tripathi
- Department of Surgery, Loyola University Chicago Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, 900 S Ashland, Chicago, IL, 60607, USA
| | - Matthias Majetschak
- Department of Surgery, Loyola University Chicago Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA.
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL, 60153, USA.
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25
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Nagler M, Palkowitsch L, Rading S, Moepps B, Karsak M. Cannabinoid receptor 2 expression modulates Gβ(1)γ(2) protein interaction with the activator of G protein signalling 2/dynein light chain protein Tctex-1. Biochem Pharmacol 2015; 99:60-72. [PMID: 26410677 DOI: 10.1016/j.bcp.2015.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/22/2015] [Indexed: 11/19/2022]
Abstract
The activator of G protein signalling AGS2 (Tctex-1) forms protein complexes with Gβγ, and controls cell proliferation by regulating cell cycle progression. A direct interaction of Tctex-1 with various G protein-coupled receptors has been reported. Since the carboxyl terminal portion of CB2 carries a putative Tctex-1 binding motif, we investigated the potential interplay of CB2 and Tctex-1 in the absence and presence of Gβγ. The supposed interaction of cannabinoid receptor CB2 with Tctex-1 and the influence of CB2 on the formation of Tctex-1-Gβγ-complexes were studied by co- and/or immunoprecipitation experiments in transiently transfected HEK293 cells. The analysis on Tctex-1 protein was performed in the absence and presence of the ligands JWH 133, 2-AG, and AM 630, the protein biosynthesis inhibitor cycloheximide or the protein degradation blockers MG132, NH4Cl/leupeptin or bafilomycin. Our results show that CB2 neither directly nor indirectly via Gβγ interacts with Tctex-1, but competes with Tctex-1 in binding to Gβγ. The Tctex-1-Gβγ protein interaction was disrupted by CB2 receptor expression resulting in a release of Tctex-1 from the complex, and its degradation by the proteasome and partly by lysosomes. The decrease in Tctex-1 protein levels is induced by CB2 expression "dose-dependently" and is independent of stimulation by agonist or blocking by an inverse agonist treatment. The results suggest that CB2 receptor expression independent of its activation by agonists is sufficient to competitively disrupt Gβγ-Tctex-1 complexes, and to initiate Tctex-1 degradation. These findings implicate that CB2 receptor expression modifies the stability of intracellular protein complexes by a non-canonical pathway.
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Affiliation(s)
- Marina Nagler
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; Institute of Pharmacology and Toxicology, Ulm University, 89081 Ulm, Germany
| | - Lysann Palkowitsch
- Institute of Physiological Chemistry, Ulm University, 89081 Ulm, Germany
| | - Sebastian Rading
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; Institute of Pharmacology and Toxicology, Ulm University, 89081 Ulm, Germany
| | - Barbara Moepps
- Institute of Pharmacology and Toxicology, Ulm University, 89081 Ulm, Germany
| | - Meliha Karsak
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany; Institute of Pharmacology and Toxicology, Ulm University, 89081 Ulm, Germany.
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26
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Role of host β1- and β2-adrenergic receptors in a murine model of B16 melanoma: functional involvement of β3-adrenergic receptors. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:1317-31. [PMID: 26285646 DOI: 10.1007/s00210-015-1165-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 08/03/2015] [Indexed: 01/03/2023]
Abstract
Complex interactions between tumor cells and their surrounding compartment are strongly influenced by the host in which the tumor grows. In melanoma, for instance, stress-associated norephinephrine (NE), acting at β-adrenergic receptors (β-ARs), stimulates melanoma cell proliferation and tumor angiogenesis. Among β-ARs, β3-ARs play a role acting not only at tumor cells but also at non-neoplastic stromal cells within the melanoma. In the present study, we used a murine model of B16 melanoma to evaluate the role of the host β1- and β2-ARs in melanoma growth and we determined whether the role of β3-ARs can be influenced by the absence of stromal β1- and β2-ARs. As compared to wild-type mice, β1/2-AR knockout mice displayed (i) increased intratumoral levels of both NE and β3-ARs, as evidentiated at both messenger and protein levels; (ii) increased tumor vascularization; (iii) decreased tumor cell proliferation but increased tumor cell apoptosis; and (iv) increased responsiveness to intratumoral injection of the β3-AR blocker L-748,337 in terms of decrease in tumor growth, tumor vascular response, tumor cell proliferation, and increase in tumor cell death. These findings together validate the role of β-AR signaling in melanoma microenvironment suggesting that non-neoplastic stromal cells may be targeted by β-AR-related drugs. The additional fact that β3-ARs play an important role in melanoma growth suggests selective β3-AR antagonists as important proapoptotic agents.
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27
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Non-uniform changes in membrane receptors in the rat urinary bladder following outlet obstruction. Eur J Pharmacol 2015; 762:82-8. [PMID: 26004535 DOI: 10.1016/j.ejphar.2015.05.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/15/2015] [Accepted: 05/11/2015] [Indexed: 11/23/2022]
Abstract
The aim of the present study was to investigate the expression and distribution of membrane receptors after bladder outlet obstruction (BOO). Partial bladder outlet obstruction (BOO) was induced in female rats and bladders were harvested after either 10 days or 6 weeks of BOO. The expression of different receptors was surveyed by microarrays and corroborated by immunohistochemistry and western blotting. A microarray experiment identified 10 membrane receptors that were differentially expressed compared to sham-operated rats including both upregulated and downregulated receptors. Four of these were selected for functional experiments on the basis of magnitude of change and relevance to bladder physiology. At 6 weeks of BOO, maximal contraction was reduced for neuromedin B and vasopressin (AVP), consistent with reductions of receptor mRNA levels. Glycine receptor-induced contraction on the other hand was increased and receptor mRNA expression was accordingly upregulated. Maximal relaxation by the β3-adrenergic receptor agonist CL316243 was reduced as was the receptor mRNA level. Immunohistochemistry supported reduced expression of neuromedin B receptors, V1a receptors and β3-adrenergic receptors, but glycine receptor expression appeared unchanged. Western blotting confirmed repression of V1a receptors and induction of glycine receptors in BOO. mRNA for vasopressin was detectable in the bladder, suggesting local AVP production. We conclude that changes in receptor expression following bladder outlet obstruction are non-uniform. Some receptors are upregulated, conferring increased responsiveness to agonist, whereas others are downregulated, leading to decreased agonist-induced responses. This study might help to select pharmacological agents that are effective in modulating lower urinary tract symptoms in BOO.
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28
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Schonbrunn A. Editorial: Antibody can get it right: confronting problems of antibody specificity and irreproducibility. Mol Endocrinol 2015; 28:1403-7. [PMID: 25184858 DOI: 10.1210/me.2014-1230] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Agnes Schonbrunn
- Department of Integrative Biology and Pharmacology, The University of Texas Health Science Center at Houston, Houston, Texas 77225
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29
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Roca-Alonso L, Castellano L, Mills A, Dabrowska AF, Sikkel MB, Pellegrino L, Jacob J, Frampton AE, Krell J, Coombes RC, Harding SE, Lyon AR, Stebbing J. Myocardial MiR-30 downregulation triggered by doxorubicin drives alterations in β-adrenergic signaling and enhances apoptosis. Cell Death Dis 2015; 6:e1754. [PMID: 25950484 PMCID: PMC4669718 DOI: 10.1038/cddis.2015.89] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 12/14/2014] [Accepted: 01/12/2015] [Indexed: 12/22/2022]
Abstract
The use of anthracyclines such as doxorubicin (DOX) has improved outcome in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-associated cardiotoxicity is frequently irreversible and typically progresses to heart failure (HF) but our understanding of molecular mechanisms underlying this and essential for development of cardioprotective strategies remains largely obscure. As microRNAs (miRNAs) have been shown to play potent regulatory roles in both cardiovascular disease and cancer, we investigated miRNA changes in DOX-induced HF and the alteration of cellular processes downstream. Myocardial miRNA profiling was performed after DOX-induced injury, either via acute application to isolated cardiomyocytes or via chronic exposure in vivo, and compared with miRNA profiles from remodeled hearts following myocardial infarction. The miR-30 family was downregulated in all three models. We describe here that miR-30 act regulating the β-adrenergic pathway, where preferential β1- and β2-adrenoceptor (β1AR and β2AR) direct inhibition is combined with Giα-2 targeting for fine-tuning. Importantly, we show that miR-30 also target the pro-apoptotic gene BNIP3L/NIX. In aggregate, we demonstrate that high miR-30 levels are protective against DOX toxicity and correlate this in turn with lower reactive oxygen species generation. In addition, we identify GATA-6 as a mediator of DOX-associated reductions in miR-30 expression. In conclusion, we describe that DOX causes acute and sustained miR-30 downregulation in cardiomyocytes via GATA-6. miR-30 overexpression protects cardiac cells from DOX-induced apoptosis, and its maintenance represents a potential cardioprotective and anti-tumorigenic strategy for anthracyclines.
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Affiliation(s)
- L Roca-Alonso
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - L Castellano
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A Mills
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A F Dabrowska
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - M B Sikkel
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - L Pellegrino
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - J Jacob
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A E Frampton
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- Hepato-Pancreato-Biliary Surgical Unit, Department of Surgery and Cancer, Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - J Krell
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - R C Coombes
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - S E Harding
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A R Lyon
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Imperial college, London SW3 6NP, UK
| | - J Stebbing
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
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30
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Detection of mu opioid receptor (MOPR) and its glycosylation in rat and mouse brains by western blot with anti-μC, an affinity-purified polyclonal anti-MOPR antibody. Methods Mol Biol 2015; 1230:141-54. [PMID: 25293322 DOI: 10.1007/978-1-4939-1708-2_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Our experience demonstrates that it is difficult to identify MOPR in rat and mouse brains by western blot, in part due to low abundance of the receptor and a wide relative molecular mass (Mr) range of the receptor associated with its heterogeneous glycosylation states. Here, we describe generation and purification of anti-μC (a rabbit polyclonal anti-MOPR antibody), characterization of its specificity in immunoblotting of HA-tagged MOPR expressed in a cell line, and ultimately, unequivocal detection of the MOPR in brain tissues by western blot with multiple rigorous controls. In particular, using brain tissues from MOPR knockout (K/O) mice as the negative controls allowed unambiguous identification of the MOPR band, since the anti-MOPR antibody, even after affinity purification, recognizes nonspecific protein bands. The MOPR was resolved as a faint, broad, and diffuse band with a wide Mr range of 58-84 kDa depending on brain regions and species. Upon deglycosylation to remove N-linked glycans by PNGase F (but not Endo H), the MOPR became a dense and sharp band with Mr of ~43 kDa, close to the theoretical Mr of its deduced amino acid sequences. Thus, MOPRs in rodent brains are differentially glycosylated by complex type of N-linked glycans in brain region- and species-specific manners. Furthermore, we characterized the MOPR in an A112G/N38D-MOPR knockin mouse model that possesses the equivalent substitution of the A118G/N40D SNP in the human MOPR gene. The substitution removes one of the four and five N-linked consensus glycosylation sites of the mouse and human MOPR, respectively. We demonstrated that the Mr of the MOPR in A112G mouse brains was lower than that in wild-type mouse brains, and that the difference was due to lower degrees of N-linked glycosylation.
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Cathel AM, Reyes BAS, Wang Q, Palma J, Mackie K, Bockstaele EJV, Kirby LG. Cannabinoid modulation of alpha2 adrenergic receptor function in rodent medial prefrontal cortex. Eur J Neurosci 2014; 40:3202-14. [PMID: 25131562 PMCID: PMC4205194 DOI: 10.1111/ejn.12690] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 07/11/2014] [Indexed: 11/28/2022]
Abstract
Endocannabinoids acting at the cannabinoid type 1 receptor (CB1R) are known to regulate attention, cognition and mood. Previous studies have shown that, in the rat medial prefrontal cortex (mPFC), CB1R agonists increase norepinephrine release, an effect that may be attributed, in part, to CB1Rs localised to noradrenergic axon terminals. The present study was aimed at further characterising functional interactions between CB1R and adrenergic receptor (AR) systems in the mPFC using in vitro intracellular electrophysiology and high-resolution neuroanatomical techniques. Whole-cell patch-clamp recordings of layer V/VI cortical pyramidal neurons in rats revealed that both acute and chronic treatment with the synthetic CB1R agonist WIN 55,212-2 blocked elevations in cortical pyramidal cell excitability and increases in input resistance evoked by the α2-adrenergic receptor (α2-AR) agonist clonidine, suggesting a desensitisation of α2-ARs. These CB1R-α2-AR interactions were further shown to be both action potential- and gamma-aminobutyric acid-independent. To better define sites of cannabinoid-AR interactions, we localised α2A-adrenergic receptors (α2A-ARs) in a genetically modified mouse that expressed a hemoagglutinin (HA) tag downstream of the α2A-AR promoter. Light and electron microscopy indicated that HA-α2A-AR was distributed in axon terminals and somatodendritic processes especially in layer V of the mPFC. Triple-labeling immunocytochemistry revealed that α2A-AR and CB1R were localised to processes that contained dopamine-β-hydroxylase, a marker of norepinephrine. Furthermore, HA-α2A-AR was localised to processes that were directly apposed to CB1R. These findings suggest multiple sites of interaction between cortical cannabinoid-adrenergic systems that may contribute to understanding the effect of cannabinoids on executive functions and mood.
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MESH Headings
- Action Potentials/drug effects
- Adrenergic alpha-2 Receptor Agonists/pharmacology
- Animals
- Benzoxazines/pharmacology
- Clonidine/pharmacology
- Gene Knock-In Techniques
- Male
- Mice
- Morpholines/pharmacology
- Naphthalenes/pharmacology
- Prefrontal Cortex/drug effects
- Prefrontal Cortex/physiology
- Prefrontal Cortex/ultrastructure
- Pyramidal Cells/drug effects
- Pyramidal Cells/physiology
- Pyramidal Cells/ultrastructure
- Rats
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/physiology
- Receptors, Adrenergic, alpha-2/analysis
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, alpha-2/physiology
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Affiliation(s)
- Alessandra M. Cathel
- Department of Anatomy and Cell Biology, Center for Substance Abuse Research, Temple University School of Medicine, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Beverly A. S. Reyes
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Qin Wang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jonathan Palma
- Department of Anatomy and Cell Biology, Center for Substance Abuse Research, Temple University School of Medicine, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Kenneth Mackie
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | | | - Lynn G. Kirby
- Department of Anatomy and Cell Biology, Center for Substance Abuse Research, Temple University School of Medicine, 3500 N. Broad Street, Philadelphia, PA 19140, USA
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The β-adrenergic system as a possible new target for pharmacologic treatment of neovascular retinal diseases. Prog Retin Eye Res 2014; 42:103-29. [DOI: 10.1016/j.preteyeres.2014.06.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 12/31/2022]
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Rat β3-adrenoceptor protein expression: antibody validation and distribution in rat gastrointestinal and urogenital tissues. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:1117-27. [DOI: 10.1007/s00210-014-1039-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 08/18/2014] [Indexed: 12/31/2022]
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34
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Gotfredsen CF, Mølck AM, Thorup I, Nyborg NCB, Salanti Z, Knudsen LB, Larsen MO. The human GLP-1 analogs liraglutide and semaglutide: absence of histopathological effects on the pancreas in nonhuman primates. Diabetes 2014; 63:2486-97. [PMID: 24608440 DOI: 10.2337/db13-1087] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased pancreas mass and glucagon-positive adenomas have been suggested to be a risk associated with sitagliptin or exenatide therapy in humans. Novo Nordisk has conducted extensive toxicology studies, including data on pancreas weight and histology, in Cynomolgus monkeys dosed with two different human glucagon-like peptide-1 (GLP-1) receptor agonists. In a 52-week study with liraglutide, a dose-related increase in absolute pancreas weight was observed in female monkeys only. Such dose-related increase was not found in studies of 4, 13, or 87 weeks' duration. No treatment-related histopathological abnormalities were observed in any of the studies. Quantitative histology of the pancreas from the 52-week study showed an increase in the exocrine cell mass in liraglutide-dosed animals, with normal composition of endocrine and exocrine cellular compartments. Proliferation rate of the exocrine tissue was low and comparable between groups. Endocrine cell mass and proliferation rates were unaltered by liraglutide treatment. Semaglutide showed no increase in pancreas weight and no treatment-related histopathological findings in the pancreas after 13 or 52 weeks' dosing. Overall, results in 138 nonhuman primates showed no histopathological changes in the pancreas associated with liraglutide or semaglutide, two structurally different GLP-1 receptor agonists.
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Affiliation(s)
| | | | - Inger Thorup
- Diabetes Research Unit, Novo Nordisk, Måløv, Denmark
| | | | - Zaki Salanti
- Diabetes Research Unit, Novo Nordisk, Måløv, Denmark
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Fève M, Saliou JM, Zeniou M, Lennon S, Carapito C, Dong J, Van Dorsselaer A, Junier MP, Chneiweiss H, Cianférani S, Haiech J, Kilhoffer MC. Comparative expression study of the endo-G protein coupled receptor (GPCR) repertoire in human glioblastoma cancer stem-like cells, U87-MG cells and non malignant cells of neural origin unveils new potential therapeutic targets. PLoS One 2014; 9:e91519. [PMID: 24662753 PMCID: PMC3963860 DOI: 10.1371/journal.pone.0091519] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Accepted: 02/10/2014] [Indexed: 12/22/2022] Open
Abstract
Glioblastomas (GBMs) are highly aggressive, invasive brain tumors with bad prognosis and unmet medical need. These tumors are heterogeneous being constituted by a variety of cells in different states of differentiation. Among these, cells endowed with stem properties, tumor initiating/propagating properties and particularly resistant to chemo- and radiotherapies are designed as the real culprits for tumor maintenance and relapse after treatment. These cells, termed cancer stem-like cells, have been designed as prominent targets for new and more efficient cancer therapies. G-protein coupled receptors (GPCRs), a family of membrane receptors, play a prominent role in cell signaling, cell communication and crosstalk with the microenvironment. Their role in cancer has been highlighted but remains largely unexplored. Here, we report a descriptive study of the differential expression of the endo-GPCR repertoire in human glioblastoma cancer stem-like cells (GSCs), U-87 MG cells, human astrocytes and fetal neural stem cells (f-NSCs). The endo-GPCR transcriptome has been studied using Taqman Low Density Arrays. Of the 356 GPCRs investigated, 138 were retained for comparative studies between the different cell types. At the transcriptomic level, eight GPCRs were specifically expressed/overexpressed in GSCs. Seventeen GPCRs appeared specifically expressed in cells with stem properties (GSCs and f-NSCs). Results of GPCR expression at the protein level using mass spectrometry and proteomic analysis are also presented. The comparative GPCR expression study presented here gives clues for new pathways specifically used by GSCs and unveils novel potential therapeutic targets.
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Affiliation(s)
- Marie Fève
- Laboratoire d'Innovation Thérapeutique, UMR7200, Laboratoire d'Excellence Medalis, CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Jean-Michel Saliou
- Laboratoire de Spectrométrie de Masse BioOrganique, UMR7178, CNRS, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Maria Zeniou
- Laboratoire d'Innovation Thérapeutique, UMR7200, Laboratoire d'Excellence Medalis, CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Sarah Lennon
- Laboratoire de Spectrométrie de Masse BioOrganique, UMR7178, CNRS, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse BioOrganique, UMR7178, CNRS, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Jihu Dong
- Laboratoire d'Innovation Thérapeutique, UMR7200, Laboratoire d'Excellence Medalis, CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie de Masse BioOrganique, UMR7178, CNRS, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Marie-Pierre Junier
- Neuroscience Paris Seine, UMR8246, Inserm U1130, Institut de Biologie Paris Seine, CNRS, Université Pierre et Marie Curie, Paris, France
| | - Hervé Chneiweiss
- Neuroscience Paris Seine, UMR8246, Inserm U1130, Institut de Biologie Paris Seine, CNRS, Université Pierre et Marie Curie, Paris, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, UMR7178, CNRS, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Jacques Haiech
- Laboratoire d'Innovation Thérapeutique, UMR7200, Laboratoire d'Excellence Medalis, CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
| | - Marie-Claude Kilhoffer
- Laboratoire d'Innovation Thérapeutique, UMR7200, Laboratoire d'Excellence Medalis, CNRS, Université de Strasbourg, Faculté de Pharmacie, Illkirch, France
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Talmont F, Moulédous L. Evaluation of commercial antibodies against human sphingosine-1-phosphate receptor 1. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:427-31. [DOI: 10.1007/s00210-014-0957-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 01/06/2014] [Indexed: 01/06/2023]
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Cécyre B, Thomas S, Ptito M, Casanova C, Bouchard JF. Evaluation of the specificity of antibodies raised against cannabinoid receptor type 2 in the mouse retina. Naunyn Schmiedebergs Arch Pharmacol 2013; 387:175-84. [DOI: 10.1007/s00210-013-0930-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 10/14/2013] [Indexed: 12/11/2022]
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38
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van Wieringen JP, Michel-Reher MB, Hatanaka T, Ueshima K, Michel MC. The new radioligand [(3)H]-L 748,337 differentially labels human and rat β3-adrenoceptors. Eur J Pharmacol 2013; 720:124-30. [PMID: 24183974 DOI: 10.1016/j.ejphar.2013.10.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Revised: 10/16/2013] [Accepted: 10/17/2013] [Indexed: 10/26/2022]
Abstract
As no suitable radioligand exists for the detection of β3-adrenoceptors, we have explored the radioligand binding properties of a tritiated version of the selective β3-adrenoceptor antagonist L 748,337. Kinetic and equilibrium saturation and competition binding experiments were performed with [(3)H]-L 748,337 on membrane fractions of HEK and CHO cells stably transfected with human and rat β-adrenoceptor subtypes. Based on both association/dissociation kinetic and equilibrium saturation binding studies in transfected HEK cells, [(3)H]-L 748,337 exhibited an affinity of approximately 2 nM for human β3-adrenoceptors. Competition studies with agonists and subtype-selective antagonists validated its binding to β3-adrenoceptors. In CHO cells transfected with human β3-adrenoceptors similar saturable high-affinity of [(3)H]-L 748,337 was observed. While some isoprenaline-sensitive [(3)H]-L 748,337 binding was also observed in CHO cells transfected with human β1- or β2-adrenoceptors, this was not saturable in a similar concentration range and/or not sensitive to the antagonists propranolol and SR 59,230, indicating that it did not primarily involve β-adrenoceptors. In CHO cells transfected with rat β3-adrenoceptors [(3)H]-L 748,337 exhibited a considerably lower affinity than with the human subtype (12-95 nM). Low affinity for the rat β3-adrenoceptor was also found with unlabelled L 748,337 in rat bladder strip relaxation experiments. We conclude that L 748,337 apparently has lower affinity for the rat than the human β3-adrenoceptors and that [(3)H]-L 748,337 can bind to a low-affinity site distinct from the orthosteric pocket of β-adrenoceptors. Nevertheless, [(3)H]-L 748,337 appears to be the most promising radioligand for the selective labelling of human β3-adrenoceptors reported to date.
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Erickson CE, Gul R, Blessing CP, Nguyen J, Liu T, Pulakat L, Bastepe M, Jackson EK, Andresen BT. The β-blocker Nebivolol Is a GRK/β-arrestin biased agonist. PLoS One 2013; 8:e71980. [PMID: 23977191 PMCID: PMC3748024 DOI: 10.1371/journal.pone.0071980] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 07/07/2013] [Indexed: 01/14/2023] Open
Abstract
Nebivolol, a third generation β-adrenoceptor (β-AR) antagonist (β-blocker), causes vasodilation by inducing nitric oxide (NO) production. The mechanism via which nebivolol induces NO production remains unknown, resulting in the genesis of much of the controversy regarding the pharmacological action of nebivolol. Carvedilol is another β-blocker that induces NO production. A prominent pharmacological mechanism of carvedilol is biased agonism that is independent of Gαs and involves G protein-coupled receptor kinase (GRK)/β-arrestin signaling with downstream activation of the epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK). Due to the pharmacological similarities between nebivolol and carvedilol, we hypothesized that nebivolol is also a GRK/β-arrestin biased agonist. We tested this hypothesis utilizing mouse embryonic fibroblasts (MEFs) that solely express β2-ARs, and HL-1 cardiac myocytes that express β1- and β2-ARs and no detectable β3-ARs. We confirmed previous reports that nebivolol does not significantly alter cAMP levels and thus is not a classical agonist. Moreover, in both cell types, nebivolol induced rapid internalization of β-ARs indicating that nebivolol is also not a classical β-blocker. Furthermore, nebivolol treatment resulted in a time-dependent phosphorylation of ERK that was indistinguishable from carvedilol and similar in duration, but not amplitude, to isoproterenol. Nebivolol-mediated phosphorylation of ERK was sensitive to propranolol (non-selective β-AR-blocker), AG1478 (EGFR inhibitor), indicating that the signaling emanates from β-ARs and involves the EGFR. Furthermore, in MEFs, nebivolol-mediated phosphorylation of ERK was sensitive to pharmacological inhibition of GRK2 as well as siRNA knockdown of β-arrestin 1/2. Additionally, nebivolol induced redistribution of β-arrestin 2 from a diffuse staining pattern into more intense punctate spots. We conclude that nebivolol is a β2-AR, and likely β1-AR, GRK/β-arrestin biased agonist, which suggests that some of the unique clinically beneficial effects of nebivolol may be due to biased agonism at β1- and/or β2-ARs.
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Affiliation(s)
- Catherine E. Erickson
- Department of Internal Medicine, University of Missouri, Columbia, Missouri, United States of America
- Harry S Truman Memorial Veterans’ Hospital, Columbia, Missouri, United States of America
| | - Rukhsana Gul
- Department of Internal Medicine, University of Missouri, Columbia, Missouri, United States of America
- Harry S Truman Memorial Veterans’ Hospital, Columbia, Missouri, United States of America
- Obesity Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Christopher P. Blessing
- Department of Internal Medicine, University of Missouri, Columbia, Missouri, United States of America
| | - Jenny Nguyen
- Department of Pharmaceutical Sciences, Western University of Health Sciences, Pomona, California, United States of America
| | - Tammy Liu
- Department of Pharmaceutical Sciences, Western University of Health Sciences, Pomona, California, United States of America
| | - Lakshmi Pulakat
- Department of Internal Medicine, University of Missouri, Columbia, Missouri, United States of America
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri, United States of America
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America
- Harry S Truman Memorial Veterans’ Hospital, Columbia, Missouri, United States of America
| | - Murat Bastepe
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Edwin K. Jackson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh Pennsylvania, United States of America
| | - Bradley T. Andresen
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America
- Department of Pharmaceutical Sciences, Western University of Health Sciences, Pomona, California, United States of America
- * E-mail:
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Hafko R, Villapol S, Nostramo R, Symes A, Sabban EL, Inagami T, Saavedra JM. Commercially available angiotensin II At₂ receptor antibodies are nonspecific. PLoS One 2013; 8:e69234. [PMID: 23840911 PMCID: PMC3698141 DOI: 10.1371/journal.pone.0069234] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 06/06/2013] [Indexed: 12/31/2022] Open
Abstract
Commercially available angiotensin II At₂ receptor antibodies are widely employed for receptor localization and quantification, but they have not been adequately validated. In this study, we characterized three commercially available At₂ receptor antibodies: 2818-1 from Epitomics, sc-9040 from Santa Cruz Biotechnology, Inc., and AAR-012 from Alomone Labs. Using western blot analysis the immunostaining patterns observed were different for every antibody tested, and in most cases consisted of multiple immunoreactive bands. Identical immunoreactive patterns were present in wild-type and At₂ receptor knockout mice not expressing the target protein. In the mouse brain, immunocytochemical studies revealed very different cellular immunoreactivity for each antibody tested. While the 2818-1 antibody reacted only with endothelial cells in small parenchymal arteries, the sc-9040 antibody reacted only with ependymal cells lining the cerebral ventricles, and the AAR-012 antibody reacted only with multiple neuronal cell bodies in the cerebral cortex. Moreover, the immunoreactivities were identical in brain tissue from wild-type or At₂ receptor knockout mice. Furthermore, in both mice and rat tissue extracts, there was no correlation between the observed immunoreactivity and the presence or absence of At₂ receptor binding or gene expression. We conclude that none of these commercially available At₂ receptor antibodies tested met the criteria for specificity. In the absence of full antibody characterization, competitive radioligand binding and determination of mRNA expression remain the only reliable approaches to study At₂ receptor expression.
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Affiliation(s)
- Roman Hafko
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sonia Villapol
- Centre for Neuroscience and Regenerative Medicine, Bethesda, Maryland, United States of America
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Regina Nostramo
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Aviva Symes
- Centre for Neuroscience and Regenerative Medicine, Bethesda, Maryland, United States of America
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Esther L. Sabban
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, United States of America
| | - Tadashi Inagami
- Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Juan M. Saavedra
- Section on Pharmacology, Division of Intramural Research Programs, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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AMPK is involved in the regulation of incretin receptors expression in pancreatic islets under a low glucose concentration. PLoS One 2013; 8:e64633. [PMID: 23717642 PMCID: PMC3661597 DOI: 10.1371/journal.pone.0064633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 04/17/2013] [Indexed: 01/09/2023] Open
Abstract
The precise role of AMP-activated protein kinase (AMPK), a target of metformin, in pancreatic β cells remains controversial, even though metformin was recently shown to enhance the expression of incretin receptors (GLP-1 and GIP receptors) in pancreatic β cells. In this study, we investigated the effect of AMPK in the regulation of incretin receptors expression in pancreatic islets. The phosphorylation of AMPK in the mouse islets was decreased by increasing glucose concentrations. We showed the expression of incretin receptors in bell-shaped response to glucose; Expression of the incretin receptors in the isolated islets showed higher levels under a medium glucose concentration (11.1 mM) than that under a low glucose concentration (2.8 mM), but was suppressed under a high glucose concentration (22.2 mM). Both treatment with an AMPK inhibitor and DN-AMPK expression produced a significant increase of the incretin receptors expression under a low glucose concentration. By contrast, in hyperglycemic db/db islets, the enhancing effect of the AMPK inhibitor on the expression of incretin receptors was diminished under a low glucose concentration. Taken together, AMPK is involved in the regulation of incretin receptors expression in pancreatic islets under a low glucose concentration.
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Matsumoto R, Otsuka A, Suzuki T, Shinbo H, Mizuno T, Kurita Y, Mugiya S, Ozono S. Expression and functional role of β3-adrenoceptors in the human ureter. Int J Urol 2013; 20:1007-14. [DOI: 10.1111/iju.12093] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/26/2012] [Indexed: 12/01/2022]
Affiliation(s)
- Rikiya Matsumoto
- Department of Urology; Hamamatsu University School of Medicine; Hamamatsu; Japan
| | - Atsushi Otsuka
- Department of Urology; Hamamatsu University School of Medicine; Hamamatsu; Japan
| | - Takahisa Suzuki
- Department of Urology; Hamamatsu University School of Medicine; Hamamatsu; Japan
| | | | - Takuji Mizuno
- Department of Urology; Iwata City Hospital; Iwata; Japan
| | - Yutaka Kurita
- Department of Urology; Enshu Hospital; Hamamatsu; Japan
| | - Soichi Mugiya
- Department of Urology; Hamamatsu University School of Medicine; Hamamatsu; Japan
| | - Seiichiro Ozono
- Department of Urology; Hamamatsu University School of Medicine; Hamamatsu; Japan
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Otsuka A, Kawasaki H, Matsumoto R, Shinbo H, Kurita Y, Iwashita T, Ozono S. Expression of β-Adrenoceptor Subtypes in Urothelium, Interstitial Cells and Detrusor of the Human Urinary Bladder. Low Urin Tract Symptoms 2013; 5:173-80. [PMID: 26663456 DOI: 10.1111/luts.12007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We examined whether interstitial cells (ICs) of the human urinary bladder expressed β-adrenoceptor (AR) subtypes, and semiquantitatively compared the staining intensity among urothelium, ICs and detrusor muscles. METHODS Paraffin sections of the human urinary bladder were obtained from histologically normal areas of formalin-fixed specimens removed for bladder carcinoma. Double-labeling immunohistochemical methods using antibodies against each β-AR subtype and vimentin were performed to identify ICs of the human urinary bladder. The staining intensity of β-ARs was semiquantitatively compared among urothelium, ICs and detrusor muscles. Further, gender-related difference or age-related correlation in the staining intensity of β-ARs was compared in the same cell types. RESULTS The expression of β1 -, β2 -, and β3 -AR was observed in vimentin-positive ICs localized in suburothelium, between detrusor muscle bundles, and within these bundles of the human urinary bladder. The rank order of the staining intensity was urothelium > ICs = detrusor muscles in β1 -AR, urothelium > ICs > detrusor muscles in β2 -AR, whereas its order was ICs = detrusor muscles > urothelium in β3 -AR. Except for urothelial β1 -AR, there was no gender-related difference in the signal intensity of β-ARs in the urothelium, ICs or detrusor muscles. Age negatively correlated with the signal intensity of all β-AR subtypes. CONCLUSION β-ARs were expressed in vimentin-positive ICs of the human urinary bladder. As for β2 - and β3 -AR, there was no gender-related difference or age-related correlation in urothelium, ICs and detrusor muscles. In the human urinary bladder, β-ARs expressed in ICs may play a role in bladder physiology.
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Affiliation(s)
- Atsushi Otsuka
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Hideya Kawasaki
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Rikiya Matsumoto
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Hitoshi Shinbo
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Yutaka Kurita
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Toshihide Iwashita
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
| | - Seiichiro Ozono
- Department of Urology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, JapanDepartment of Urology, Enshu Hospital, Hamamatsu, Japan
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Seifert R, Strasser A, Schneider EH, Neumann D, Dove S, Buschauer A. Molecular and cellular analysis of human histamine receptor subtypes. Trends Pharmacol Sci 2013; 34:33-58. [PMID: 23254267 PMCID: PMC3869951 DOI: 10.1016/j.tips.2012.11.001] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/03/2012] [Accepted: 11/05/2012] [Indexed: 01/08/2023]
Abstract
The human histamine receptors hH(1)R and hH(2)R constitute important drug targets, and hH(3)R and hH(4)R have substantial potential in this area. Considering the species-specificity of pharmacology of H(x)R orthologs, it is important to analyze hH(x)Rs. Here, we summarize current knowledge of hH(x)Rs endogenously expressed in human cells and hH(x)Rs recombinantly expressed in mammalian and insect cells. We present the advantages and disadvantages of the various systems. We also discuss problems associated with the use of hH(x)R antibodies, an issue of general relevance for G-protein-coupled receptors (GPCRs). There is much greater overlap in activity of 'selective' ligands for other hH(x)Rs than the cognate receptor subtype than generally appreciated. Studies with native and recombinant systems support the concept of ligand-specific receptor conformations, encompassing agonists and antagonists. It is emerging that for characterization of hH(x)R ligands, one cannot rely on a single test system and a single parameter. Rather, multiple systems and parameters have to be studied. Although such studies are time-consuming and expensive, ultimately, they will increase drug safety and efficacy.
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Affiliation(s)
- Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Hannover, Germany.
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Herrera M, Sparks MA, Alfonso-Pecchio AR, Harrison-Bernard LM, Coffman TM. Lack of specificity of commercial antibodies leads to misidentification of angiotensin type 1 receptor protein. Hypertension 2012; 61:253-8. [PMID: 23150519 DOI: 10.1161/hypertensionaha.112.203679] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The angiotensin II type 1 receptor (AT(1)R) mediates most hypertensive actions of angiotensin II. To understand the molecular regulation of the AT(1)R in normal physiology and pathophysiology, methods for sensitive and specific detection of AT(1)R protein are required. Here, we examined the specificity of a panel of putative AT(1)R antibodies that are commonly used by investigators in the field. For these studies, we carried out Western blotting and immunohistochemistry with kidney tissue from wild-type mice and genetically modified mice lacking the major murine AT(1)R isoform, AT(1A) (AT(1A)KO), or with combined deficiency of both the AT(1A) and AT(1B) isoforms (AT(1AB)KO). For the 3 antibodies tested, Western blots of protein homogenates from wild-type kidneys yielded distinct bands with the expected size range for AT(1)R. In addition, these bands appeared identical in samples from mice lacking 1 or both murine AT(1)R isoforms. Additionally, the pattern of immunohistochemical staining in kidneys, liver, and adrenal glands of wild-type mice was very similar to that of AT(1AB)KO mice completely lacking all AT(1)R. We verified the absence of AT(1)R subtypes in each mouse line by the following: (1) quantitative polymerase chain reaction documenting the absence of mRNA species, and (2) functionally by assessing angiotensin II-dependent vasoconstriction, which was substantially blunted in both AT(1A)KOs and AT(1AB)KOs. Finally, these antibodies failed to detect epitope-tagged AT(1A)R protein overexpressed in human embryonic kidney cells. We conclude that anti-AT(1)R antibodies available from commercial sources and commonly used in published studies exhibit nonspecific binding in mouse tissue that may lead to erroneous results.
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Affiliation(s)
- Marcela Herrera
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, NC, USA.
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Talmont F, Moulédous L, Boué J, Mollereau C, Dietrich G. Denatured G-protein coupled receptors as immunogens to generate highly specific antibodies. PLoS One 2012; 7:e46348. [PMID: 23029489 PMCID: PMC3459905 DOI: 10.1371/journal.pone.0046348] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 08/31/2012] [Indexed: 12/12/2022] Open
Abstract
G-protein coupled receptors (GPCRs) play a major role in a number of physiological and pathological processes. Thus, GPCRs have become the most frequent targets for development of new therapeutic drugs. In this context, the availability of highly specific antibodies may be decisive to obtain reliable findings on localization, function and medical relevance of GPCRs. However, the rapid and easy generation of highly selective anti-GPCR antibodies is still a challenge. Herein, we report that highly specific antibodies suitable for detection of GPCRs in native and unfolded forms can be elicited by immunizing animals against purified full length denatured recombinant GPCRs. Contrasting with the currently admitted postulate, our study shows that an active and well-folded GPCR is not required for the production of specific anti-GPCR antibodies. This new immunizing strategy validated with three different human GPCR (μ-opioid, κ-opioid, neuropeptide FF2 receptors) might be generalized to other members of the GPCR family.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies/immunology
- Antibodies/isolation & purification
- Humans
- Immunization
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/immunology
- Immunoglobulin G/isolation & purification
- Mice
- Mice, Inbred BALB C
- Molecular Sequence Data
- Pichia/genetics
- Protein Denaturation
- Protein Folding
- Receptors, Neuropeptide/administration & dosage
- Receptors, Neuropeptide/genetics
- Receptors, Neuropeptide/immunology
- Receptors, Opioid, kappa/administration & dosage
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/immunology
- Receptors, Opioid, mu/administration & dosage
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/immunology
- Recombinant Proteins/administration & dosage
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
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Affiliation(s)
- Franck Talmont
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France.
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Evaluation of antibodies directed against human protease-activated receptor-2. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:861-73. [PMID: 22842724 DOI: 10.1007/s00210-012-0783-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 07/13/2012] [Indexed: 12/29/2022]
Abstract
Protease-activated receptor 2 (PAR2) is a G protein-coupled receptor activated by intramolecular docking of a tethered ligand that is released by the actions of proteases, mainly of the serine protease family. Here, we evaluate four commercially available anti-PAR2 antibodies, SAM11, C17, N19 and H99, demonstrating marked differences in the ability of these reagents to detect the target receptor in Western blot, immunocytochemical and flow cytometry applications. In Western blot analysis, we evaluated antibody reactivity against both ectopic and endogenous receptors. Against material from transfected cells, we show that SAM11 and N19, and to a lesser extent C17, but not H99, are able to detect ectopic PAR2. Interestingly, these Western blot analyses indicate that N19 and C17 detect conformations of ectopic PAR2 distinct to those recognised by SAM11. Significantly, our data also indicate that Western blot signal detected by SAM11 and C17, and much of the signal detected by N19, against cells endogenously expressing PAR2 is non-specific. Despite confounding non-specific signals, we were able to discern N19 reactivity against endogenous PAR2 as a broad smear that we also observed in ectopically expressing human and mouse cells and that is sensitive to loss of N-glycosylation. In immunocytochemistry analysis, each antibody is able to detect ectopic PAR2 although it appears that H99 detects only a subset of the ectopically expressed receptor. In addition, SAM11 and N19 are able to detect both ectopic and endogenous cell surface PAR2 by flow cytometry. In summary: (1) each antibody can detect ectopic PAR2 by immunocytochemical analysis with SAM11 and N19 suitable for cell surface detection of both ectopic and endogenous receptor by flow cytometry; (2) in Western blot analysis, N19, SAM11 and C17 can detect ectopically expressed PAR2, with only N19 able to detect the endogenous receptor by this technique and (3) in each of these approaches, appropriate controls are essential to ensure that non-specific reactivity is identified.
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Six commercially available angiotensin II AT1 receptor antibodies are non-specific. Cell Mol Neurobiol 2012; 32:1353-65. [PMID: 22843099 DOI: 10.1007/s10571-012-9862-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 07/05/2012] [Indexed: 12/31/2022]
Abstract
Commercially available Angiotensin II AT1 receptor antibodies are widely employed for receptor localization and quantification, but they have not been adequately validated. In this study, six commercially available AT1 receptor antibodies were characterized by established criteria: sc-1173 and sc-579 from Santa Cruz Biotechnology, Inc., AAR-011 from Alomone Labs, Ltd., AB15552 from Millipore, and ab18801 and ab9391 from Abcam. The immunostaining patterns observed were different for every antibody tested, and were unrelated to the presence or absence of AT1 receptors. The antibodies detected a 43 kDa band in western blots, corresponding to the predicted size of the native AT1 receptor. However, identical bands were observed in wild-type mice and in AT1A knock-out mice not expressing the target protein. Moreover, immunoreactivity detected in rat hypothalamic 4B cells not expressing AT1 receptors or transfected with AT1A receptor construct was identical, as revealed by western blotting and immunocytochemistry in cultured 4B cells. Additional prominent immunoreactive bands above and below 43 kDa were observed by western blotting in extracts from tissues of AT1A knock-out and wild-type mice and in 4B cells with or without AT1 receptor expression. In all cases, the patterns of immunoreactivity were independent of the AT1 receptor expression and different for each antibody studied. We conclude that, in our experimental setup, none of the commercially available AT1 receptor antibodies tested met the criteria for specificity and that competitive radioligand binding remains the only reliable approach to study AT1 receptor physiology in the absence of full antibody characterization.
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Specificity evaluation of antibodies against human β3-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:875-82. [PMID: 22688595 DOI: 10.1007/s00210-012-0767-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 05/24/2012] [Indexed: 10/27/2022]
Abstract
β(3)-Adrenoceptors are a promising drug target for the treatment of urinary bladder dysfunction, but knowledge about their expression at the protein level and their functional role is limited, partly due to a lack of well validated tools. As many antibodies against G-protein-coupled receptors, including those against β(3)- and other β-adrenoceptor subtypes, lack selectivity for their target, we have evaluated the specificity of five antibodies raised against the full-length protein of the human β(3)-adrenoceptor (H155-B01), its N-terminus (LSA4198 and TA303277) and its C-terminus (AB5122, Sc1472) in immunoblotting and immunocytochemistry. Our primary test system were Chinese hamster ovary cells stably transfected to express each of the three human β-adrenoceptor subtypes at near physiological levels (100-200 fmol/mg protein). None of the five antibodies exhibited convincing target specificity in immunoblotting with Sc1472 apparently being least unsuitable. In immunocytochemistry, LSA4198 and Sc1472 appeared most promising, exhibiting at least some degree of specificity. As these two antibodies have been raised against different epitopes (N- and C-terminus of the receptor, respectively), we propose that concordant staining by both antibodies provides the most convincing evidence for β(3)-adrenoceptor labelling in cyto- or histochemistry studies.
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