1
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Dwaib H, Michel MC. Adrenoceptor Expression and Function in the Endocrine Pancreas. Handb Exp Pharmacol 2024. [PMID: 38872059 DOI: 10.1007/164_2024_717] [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: 06/15/2024]
Abstract
The sympathetic nervous system plays an important role in the regulation of endocrine pancreatic function, most importantly insulin release. Among the nine adrenoceptor (AR) subtypes, the α2A-AR appears to be the subtype most abundantly expressed in the human pancreas. While α2- and β-AR have opposing effects, the net response to sympathetic stimulation is inhibition of insulin secretion mediated by α2-AR located in the plasma membrane of pancreatic β cells. This inhibition may be present physiologically as evidenced by increased insulin secretion in healthy and diabetic humans and animals in response to α2-AR antagonists, a finding that was confirmed in all studies. Based on such data and on an association of an α2A-AR polymorphism, that increases receptor expression levels, with an elevated risk for diabetes, increased α2A-AR signaling in the pancreatic β cells has been proposed as a risk factor for the development of type 2 diabetes. Thus, the α2A-AR was proposed as a drug target for the treatment of some forms of type 2 diabetes. Drug research and development programs leveraging this mechanism have reached the clinical stage, but none have resulted in an approved medicine due to a limited efficacy. While β-AR agonists can increase circulating insulin levels in vivo, it remains controversial whether this includes a direct effect on β cells or occurs secondary to general metabolic effects. Therefore, the regulation of endocrine pancreatic function is physiologically interesting but may be of limited therapeutic relevance.
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Affiliation(s)
- Haneen Dwaib
- Department of Clinical Nutrition and Dietetics, Palestine Ahliya University, Bethlehem, Palestine.
| | - Martin C Michel
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
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2
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Petereit C, Porath K, Rackow S, Kernig K, Hakenberg OW, Köhling R, Kirschstein T. Age-dependent effects of the β 3 adrenoceptor agonist CL316,243 on human and rat detrusor muscle strips. Pflugers Arch 2024; 476:243-256. [PMID: 37993748 DOI: 10.1007/s00424-023-02877-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/19/2023] [Accepted: 10/30/2023] [Indexed: 11/24/2023]
Abstract
Motility of detrusor smooth muscle includes adrenergic relaxation and cholinergic contraction. Since the latter may be deregulated in overactive bladder (OAB) pathophysiology, anticholinergics are the standard therapy but occasionally less tolerated due to side effects such as dry mouth and constipation. β3 adrenoceptor agonists also alleviate OAB symptoms by relaxing the detrusor muscle. Their age dependence, however, is far from understood. To address this issue, we induced contractions with KCl (60 mM) and carbachol (from 10 nM to 100 μM) in the presence of the β3 adrenoceptor agonist CL316,243 (from 0.1 to 10 μM) in both human and rat muscle strips. Our results confirmed that both contractions were attenuated by β3 adrenoceptor activation in both species, but with differing age dependence. In humans, specimens from mid-life subjects showed a significantly more pronounced effect of CL316,243 in attenuating carbachol-induced contractions than those from aged subjects (Cohen's d of maximal attenuation: 1.82 in mid-life versus 0.13 in aged) without altering EC50. Conversely, attenuation of KCl responses by CL316,243 increased during ageing (Spearman correlation coefficient = -0.584, P<0.01). In rats, both KCl- and carbachol-induced contractions were significantly more attenuated by CL316,243 in samples from adolescent as compared to aged samples. Immunohistochemistry in human detrusor sections proved β3 adrenoreceptor abundance to remain unaltered during ageing. In conclusion, our findings suggest differential age-dependent changes in human β3 adrenoceptor-dependent attenuation of detrusor contraction in terms of electromechanical versus pharmacomechanical coupling; they may help understand the differential responsiveness of OAB patients to β3 agents.
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Affiliation(s)
- Charlotte Petereit
- Oscar Langendorff Institute of Physiology, University of Rostock, Gertrudenstrasse 9, 18057, Rostock, Germany
| | - Katrin Porath
- Oscar Langendorff Institute of Physiology, University of Rostock, Gertrudenstrasse 9, 18057, Rostock, Germany
| | - Simone Rackow
- Oscar Langendorff Institute of Physiology, University of Rostock, Gertrudenstrasse 9, 18057, Rostock, Germany
| | - Karoline Kernig
- Department of Urology, University of Rostock, Rostock, Germany
| | | | - Rüdiger Köhling
- Oscar Langendorff Institute of Physiology, University of Rostock, Gertrudenstrasse 9, 18057, Rostock, Germany
- Center of Transdisciplinary Neurosciences Rostock (CTNR), University of Rostock, Rostock, Germany
| | - Timo Kirschstein
- Oscar Langendorff Institute of Physiology, University of Rostock, Gertrudenstrasse 9, 18057, Rostock, Germany.
- Center of Transdisciplinary Neurosciences Rostock (CTNR), University of Rostock, Rostock, Germany.
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Pautz A, Michel MC. Sex and Gender Differences in the Pharmacology of the Overactive Urinary Bladder. Handb Exp Pharmacol 2023; 282:57-74. [PMID: 37439844 DOI: 10.1007/164_2023_667] [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: 07/14/2023]
Abstract
Dysfunction of the lower urinary tract in general and the overactive bladder syndrome (OAB) in particular are prevalent and have major impact on the quality of life of the afflicted patients and their partners. We concisely review sex and gender differences in patients and animal models in physiological bladder function, its alterations in disease (mostly OAB), and its responses to treatment. Women appear to have a smaller functional bladder capacity and, therefore, must void more often than men. On the other hand, men have a greater bladder outlet resistance, which is partly attributed to a longer urethra and partly to the presence of the prostate. Sex and gender differences in bladder contractility appear small and were not found consistently. The ability of bladder smooth muscle to relax may be somewhat smaller in females. However, females are heavily underrepresented in experimental studies on bladder function. Stress urinary incontinence is found predominantly in women (particularly those after childbirth). OAB is similarly prevalent in men and women. Females seek treatment much more often and are overrepresented in clinical trials. Treatment responses in OAB patients are similar in both genders for oral medications, but improvements upon injections of onabotulinum toxin type A appear smaller in men. We conclude that there is no evidence for major sex and gender differences in bladder dysfunction as related to OAB and its treatment responses, but female animals are heavily underrepresented in experimental studies.
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Affiliation(s)
- Andrea Pautz
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Martin C Michel
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Mainz, Germany.
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Erdogan BR, Liu G, Arioglu-Inan E, Michel MC. Established and emerging treatments for diabetes-associated lower urinary tract dysfunction. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022; 395:887-906. [PMID: 35545721 PMCID: PMC9276575 DOI: 10.1007/s00210-022-02249-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/28/2022] [Indexed: 12/16/2022]
Abstract
Dysfunction of the lower urinary tract (LUT) including urinary bladder and urethra (and prostate in men) is one of the most frequent complications of diabetes and can manifest as overactive bladder, underactive bladder, urinary incontinence, and as aggravated symptoms of benign prostate hyperplasia. We have performed a selective literature search to review existing evidence on efficacy of classic medications for the treatment of LUT dysfunction in diabetic patients and animals, i.e., α1-adrenoceptor and muscarinic receptor antagonists, β3-adrenoceptor agonists, and phosphodiesterase type 5 inhibitors. Generally, these agents appear to have comparable efficacy in patients and/or animals with and without diabetes. We also review effects of antidiabetic medications on LUT function. Such studies have largely been performed in animal models. In the streptozotocin-induced models of type 1 diabetes, insulin can prevent and reverse alterations of morphology, function, and gene expression patterns in bladder and prostate. Typical medications for the treatment of type 2 diabetes have been studied less often, and the reported findings are not yet sufficient to derive robust conclusions. Thereafter, we review animal studies with emerging medications perhaps targeting diabetes-associated LUT dysfunction. Data with myoinositol, daidzein, and with compounds that target oxidative stress, inflammation, Rac1, nerve growth factor, angiotensin II receptor, serotonin receptor, adenosine receptor, and soluble guanylyl cyclase are not conclusive yet, but some hold promise as potential treatments. Finally, we review nonpharmacological interventions in diabetic bladder dysfunction. These approaches are relatively new and give promising results in preclinical studies. In conclusion, the insulin data in rodent models of type 1 diabetes suggest that diabetes-associated LUT function can be mostly or partially reversed. However, we propose that considerable additional experimental and clinical studies are needed to target diabetes itself or pathophysiological changes induced by chronic hyperglycemia for the treatment of diabetic uropathy.
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Affiliation(s)
- Betül R Erdogan
- Department of Pharmacology, Faculty of Pharmacy, Izmir Katip Celebi University, Izmir, Turkey
| | - Guiming Liu
- Department of Surgery, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Martin C Michel
- Department of Pharmacology, University Medical Center, Johannes Gutenberg University, Mainz, Germany.
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Faro D, Boekhoff I, Gudermann T, Breit A. Physiological Temperature Changes Fine-Tune β 2- Adrenergic Receptor-Induced Cytosolic cAMP Accumulation. Mol Pharmacol 2021; 100:203-216. [PMID: 34158361 DOI: 10.1124/molpharm.121.000309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/04/2021] [Indexed: 11/22/2022] Open
Abstract
Norepinephrine (NE) controls many vital body functions by activating adrenergic receptors (ARs). Average core body temperature (CBT) in mice is 37°C. Of note, CBT fluctuates between 36 and 38°C within 24 hours, but little is known about the effects of CBT changes on the pharmacodynamics of NE. Here, we used Peltier element-controlled incubators and challenged murine hypothalamic mHypoA -2/10 cells with temperature changes of ±1°C. We observed enhanced NE-induced activation of a cAMP-dependent luciferase reporter at 36 compared with 38°C. mRNA analysis and subtype specific antagonists revealed that NE activates β 2- and β 3-AR in mHypoA-2/10 cells. Agonist binding to the β 2-AR was temperature insensitive, but measurements of cytosolic cAMP accumulation revealed an increase in efficacy of 45% ± 27% for NE and of 62% ± 33% for the β 2-AR-selective agonist salmeterol at 36°C. When monitoring NE-promoted cAMP efflux, we observed an increase in the absolute efflux at 36°C. However, the ratio of exported to cytosolic accumulated cAMP is higher at 38°C. We also stimulated cells with NE at 37°C and measured cAMP degradation at 36 and 38°C afterward. We observed increased cAMP degradation at 38°C, indicating enhanced phosphodiesterase activity at higher temperatures. In line with these data, NE-induced activation of the thyreoliberin promoter was found to be enhanced at 36°C. Overall, we show that physiologic temperature changes fine-tune NE-induced cAMP signaling in hypothalamic cells via β 2-AR by modulating cAMP degradation and the ratio of intra- and extracellular cAMP. SIGNIFICANCE STATEMENT: Increasing cytosolic cAMP levels by activation of G protein-coupled receptors (GPCR) such as the β 2-adrenergic receptor (AR) is essential for many body functions. Changes in core body temperature are fundamental and universal factors of mammalian life. This study provides the first data linking physiologically relevant temperature fluctuations to β 2-AR-induced cAMP signaling, highlighting a so far unappreciated role of body temperature as a modulator of the prototypic class A GPCR.
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MESH Headings
- 1-Methyl-3-isobutylxanthine/pharmacology
- ARNTL Transcription Factors/metabolism
- Aminopyridines/pharmacology
- Animals
- Cell Line
- Cyclic AMP/metabolism
- Cyclic AMP Response Element-Binding Protein/metabolism
- Cytosol/metabolism
- Forkhead Transcription Factors/metabolism
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- GTP-Binding Protein alpha Subunits, Gs/physiology
- Hypothalamus/physiology
- Mice
- Neurons/physiology
- Norepinephrine/pharmacology
- Receptors, Adrenergic, beta-2/biosynthesis
- Receptors, Adrenergic, beta-2/physiology
- Receptors, Adrenergic, beta-3/biosynthesis
- Receptors, Adrenergic, beta-3/physiology
- STAT Transcription Factors/metabolism
- Salmeterol Xinafoate/pharmacology
- Signal Transduction/physiology
- Temperature
- Thyrotropin-Releasing Hormone/genetics
- Thyrotropin-Releasing Hormone/metabolism
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Affiliation(s)
- Dennis Faro
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Ingrid Boekhoff
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Thomas Gudermann
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Andreas Breit
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, München, Germany
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Erdogan BR, Michel MC, Arioglu-Inan E. Expression and Signaling of β-Adrenoceptor Subtypes in the Diabetic Heart. Cells 2020; 9:cells9122548. [PMID: 33256212 PMCID: PMC7759850 DOI: 10.3390/cells9122548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/18/2022] Open
Abstract
Diabetes is a chronic, endocrine disorder that effects millions of people worldwide. Cardiovascular complications are the major cause of diabetes-related morbidity and mortality. Cardiac β1- and β2-adrenoceptor (AR) stimulation mediates positive inotropy and chronotropy, whereas β3-AR mediates negative inotropic effect. Changes in β-AR responsiveness are thought to be an important factor that contributes to the diabetic cardiac dysfunction. Diabetes related changes in β-AR expression, signaling, and β-AR mediated cardiac function have been studied by several investigators for many years. In the present review, we have screened PubMed database to obtain relevant articles on this topic. Our search has ended up with wide range of different findings about the effect of diabetes on β-AR mediated changes both in molecular and functional level. Considering these inconsistent findings, the effect of diabetes on cardiac β-AR still remains to be clarified.
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Affiliation(s)
- Betul R. Erdogan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Department of Pharmacology, Faculty of Pharmacy, Izmir Katip Celebi University, 35620 Izmir, Turkey
| | - Martin C. Michel
- Department of Pharmacology, Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, 06560 Ankara, Turkey;
- Correspondence:
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Michel MC. α 1-adrenoceptor activity of β-adrenoceptor ligands - An expected drug property with limited clinical relevance. Eur J Pharmacol 2020; 889:173632. [PMID: 33038419 DOI: 10.1016/j.ejphar.2020.173632] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/11/2020] [Accepted: 10/02/2020] [Indexed: 12/19/2022]
Abstract
Many β-adrenoceptor agonists and antagonists including several clinically used drugs have been reported to also exhibit binding to α1-adrenoceptors. Such promiscuity within the adrenoceptor family appears to occur more often than off-target effects of drugs in general. It should not be considered surprising based on the amino acid homology among the nine adrenoceptor subtypes including the counter-ions for binding the endogenous catecholamines. When β-adrenoceptor ligands also bind to α1-adrenoceptors, they almost always act as antagonists, regardless of being agonists or antagonists at the β-adrenoceptor. The α1-adrenoceptor affinity of β-adrenoceptor ligands in most cases is at least one, and often more log units lower than at their cognate receptor. Consistent evidence from multiple investigators indicates that β-adrenoceptor ligands relatively have the highest affinity for α1A- and lowest for α1B-adrenoceptors. While promiscuity among adrenoceptor subtypes causes misleading interpretation of experimental in vitro data, it is proposed based on the law of mass action that α1-adrenoceptor binding of β-adrenoceptor ligands rarely contributes to the clinical profile of such drugs, particularly if they are agonists at the β-adrenoceptor.
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Affiliation(s)
- Martin C Michel
- Dept. of Pharmacology, Johannes Gutenberg University, Universitätsmedizin Main, Langenbeckstr. 1, 55131, Mainz, Germany.
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8
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Silva I, Magalhães-Cardoso MT, Ferreirinha F, Moreira S, Costa AF, Silva D, Vieira C, Silva-Ramos M, Correia-de-Sá P. β 3 Adrenoceptor-induced cholinergic inhibition in human and rat urinary bladders involves the exchange protein directly activated by cyclic AMP 1 favoring adenosine release. Br J Pharmacol 2020; 177:1589-1608. [PMID: 31721163 DOI: 10.1111/bph.14921] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE The mechanism by which β3 receptor agonists (e.g. mirabegron) control bladder overactivity may involve adenosine release from human and rat detrusor smooth muscle. Retrograde activation of adenosine A1 receptors reduces ACh release from cholinergic bladder nerves. β3 -Adrenoceptors usually couple to adenylyl cyclase. Here we investigated, which of the cAMP targets, protein kinase A or the exchange protein directly activated by cAMP (EPAC) could be involved in this cholinergic inhibition of the bladder. EXPERIMENTAL APPROACH [3 H]ACh and adenosine release from urothelium-denuded detrusor strips of cadaveric human organ donors and rats were measured by liquid scintillation spectrometry and HPLC, respectively. In vivo cystometry was also performed in urethane-anaesthetized rats. KEY RESULTS The exchange protein directly activated by cAMP (EPAC) inhibitor, ESI-09, prevented mirabegron- and isoprenaline-induced adenosine release from human and rat detrusor strips respectively. ESI-09, but not the PKA inhibitor, H-89, attenuated inhibition of [3 H]ACh release from stimulated (10 Hz) detrusor strips caused by activating β3 -adrenoceptors, AC (forskolin) and EPAC1 (8-CTP-2Me-cAMP). Isoprenaline-induced inhibition of [3 H]ACh release was also prevented by inhibitors of PKC (chelerythrine and Go6976) and of the equilibrative nucleoside transporter 1 (ENT1; dipyridamole and NBTI), but not by PLC inhibition with U73122. Pretreatment with ESI-09, but not with H-89, prevented the reduction of the voiding frequency caused by isoprenaline and forskolin in vivo. CONCLUSION AND IMPLICATIONS Data suggest that β3 -adrenoceptor-induced inhibition of cholinergic neurotransmission in human and rat urinary bladders involves activation of an EPAC1/PKC pathway downstream cAMP production resulting in adenosine outflow via ENT1.
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Affiliation(s)
- Isabel Silva
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - M Teresa Magalhães-Cardoso
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Fátima Ferreirinha
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Sílvia Moreira
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana Filipa Costa
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Diogo Silva
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Cátia Vieira
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Miguel Silva-Ramos
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Serviço de Urologia, Centro Hospitalar Universitário do Porto (CHUP), Porto, Portugal
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.,Center for Drug Discovery and Innovative Medicines (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
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Okeke K, Michel-Reher MB, Gravas S, Michel MC. Desensitization of cAMP Accumulation via Human β3-Adrenoceptors Expressed in Human Embryonic Kidney Cells by Full, Partial, and Biased Agonists. Front Pharmacol 2019; 10:596. [PMID: 31263412 PMCID: PMC6590479 DOI: 10.3389/fphar.2019.00596] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 05/09/2019] [Indexed: 01/04/2023] Open
Abstract
β3-Adrenoceptors couple not only to cAMP formation but, at least in some cell types, also to alternative signaling pathways such as phosphorylation of extracellular signal-regulated kinase (ERK). β3-Adrenoceptor agonists are used in long-term symptomatic treatment of the overactive bladder syndrome; it is only poorly understood which signaling pathway mediates the clinical response and whether it undergoes agonist-induced desensitization. Therefore, we used human embryonic kidney cells stably transfected with human β3-adrenoceptors to compare coupling of ligands with various degrees of efficacy, including biased agonists, to cAMP formation and ERK phosphorylation, particularly regarding desensitization. Ligands stimulated cAMP formation with a numerical rank order of isoprenaline ≥ L 755,507 ≥ CL 316,243 > solabegron > SR 59,230 > L 748,337. Except for the weakest agonist, L 748,337, pretreatment with any ligand reduced cAMP responses to freshly added isoprenaline or forskolin to a similar extent. On the other hand, we were unable to detect ERK phosphorylation despite testing a wide variation of conditions. We conclude that a minor degree of efficacy for cAMP formation may be sufficient to induced full desensitization of that response. Transfected human embryonic kidney cells are not suitable to study desensitization of ERK phosphorylation by β3-adrenoceptor stimulation.
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Affiliation(s)
- Katerina Okeke
- Department of Pharmacology, Johannes Gutenberg University Mainz, Mainz, Germany.,Department of Urology, University of Thessaly, Larissa, Greece
| | | | - Stavros Gravas
- Department of Urology, University of Thessaly, Larissa, Greece
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University Mainz, Mainz, Germany
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10
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Calvani M, Bruno G, Dal Monte M, Nassini R, Fontani F, Casini A, Cavallini L, Becatti M, Bianchini F, De Logu F, Forni G, la Marca G, Calorini L, Bagnoli P, Chiarugi P, Pupi A, Azzari C, Geppetti P, Favre C, Filippi L. β 3 -Adrenoceptor as a potential immuno-suppressor agent in melanoma. Br J Pharmacol 2019; 176:2509-2524. [PMID: 30874296 DOI: 10.1111/bph.14660] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/02/2019] [Accepted: 02/22/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Stress-related catecholamines have a role in cancer and β-adrenoceptors; specifically, β2 -adrenoceptors have been identified as new targets in treating melanoma. Recently, β3 -adrenoceptors have shown a pleiotropic effect on melanoma micro-environment leading to cancer progression. However, the mechanisms by which β3 -adrenoceptors promote this progression remain poorly understood. Catecholamines affect the immune system by modulating several factors that can alter immune cell sub-population homeostasis. Understanding the mechanisms of cancer immune-tolerance is one of the most intriguing challenges in modern research. This study investigates the potential role of β3 -adrenoceptors in immune-tolerance regulation. EXPERIMENTAL APPROACH A mouse model of melanoma in which syngeneic B16-F10 cells were injected in C57BL-6 mice was used to evaluate the effect of β-adrenoceptor blockade on the number and activity of immune cell sub-populations (Treg, NK, CD8, MDSC, macrophages, and neutrophils). Pharmacological and molecular approaches with β-blockers (propranolol and SR59230A) and specific β-adrenoceptor siRNAs targeting β2 - or β3 -adrenoceptors were used. KEY RESULTS Only β3 -, but not β2 -adrenoceptors, were up-regulated under hypoxia in peripheral blood mononuclear cells and selectively expressed in immune cell sub-populations including Treg, MDSC, and NK. SR59230A and β3 -adrenoceptor siRNAs increased NK and CD8 number and cytotoxicity, while they attenuated Treg and MDSC sub-populations in the tumour mass, blood, and spleen. SR59230A and β3 -adrenoceptor siRNAs increased the ratio of M1/M2 macrophages and N1 granulocytes. CONCLUSIONS AND IMPLICATIONS Our data suggest that β3 -adrenoceptors are involved in immune-tolerance, which opens the way for new strategic therapies to overcome melanoma growth. LINKED ARTICLES This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Maura Calvani
- Oncohematology Unit, Department of Pediatric Oncology, Meyer University Children's University Hospital, Florence, Italy
| | - Gennaro Bruno
- Department of Health Sciences, University of Florence, Florence, Italy
| | - Massimo Dal Monte
- Department of Biology, Unit of General Physiology, University of Pisa, Pisa, Italy
| | - Romina Nassini
- Department of Health Sciences, University of Florence, Florence, Italy
| | - Filippo Fontani
- Department of Health Sciences, University of Florence, Florence, Italy
| | - Arianna Casini
- Division of Immunology, Section of Pediatrics, Meyer University Children's Hospital, Florence, Italy
| | - Lorenzo Cavallini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Matteo Becatti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Francesca Bianchini
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Francesco De Logu
- Department of Health Sciences, University of Florence, Florence, Italy
| | - Giulia Forni
- Metabolic and Newborn Screening Clinical Unit, Department of Neurosciences, Meyer University Children's University Hospital, Florence, Italy
| | - Giancarlo la Marca
- Metabolic and Newborn Screening Clinical Unit, Department of Neurosciences, Meyer University Children's University Hospital, Florence, Italy
| | - Lido Calorini
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Paola Bagnoli
- Department of Biology, Unit of General Physiology, University of Pisa, Pisa, Italy
| | - Paola Chiarugi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Alberto Pupi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - Chiara Azzari
- Department of Health Sciences, University of Florence, Florence, Italy
| | | | - Claudio Favre
- Oncohematology Unit, Department of Pediatric Oncology, Meyer University Children's University Hospital, Florence, Italy
| | - Luca Filippi
- Neonatal Intensive Care Unit, Medical Surgical Fetal-Neonatal Department, Meyer University Children's Hospital, Florence, Italy
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11
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Arioglu-Inan E, Kayki-Mutlu G, Michel MC. Cardiac β 3 -adrenoceptors-A role in human pathophysiology? Br J Pharmacol 2019; 176:2482-2495. [PMID: 30801686 DOI: 10.1111/bph.14635] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/11/2019] [Accepted: 01/29/2019] [Indexed: 01/06/2023] Open
Abstract
As β3 -adrenoceptors were first demonstrated to be expressed in adipose tissue they have received much attention for their metabolic effects in obesity and diabetes. After the existence of this subtype had been suggested to be present in the heart, studies focused on its role in cardiac function. While the presence and functional role of β3 -adrenoceptors in the heart has not uniformly been detected, there is a broad consensus that they become up-regulated in pathological conditions associated with increased sympathetic activity such as heart failure and diabetes. When detected, the β3 -adrenceptor has been demonstrated to mediate negative inotropic effects in an inhibitory G protein-dependent manner through the NO-cGMP-PKG signalling pathway. Whether these negative inotropic effects provide protection from the adverse effects induced by overstimulation of β1 /β2 -adrenoceptors or in themselves are potentially harmful is controversial, but ongoing clinical studies in patients with congestive heart failure are testing the hypothesis that β3 -adrenceptor agonism has a beneficial effect. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Gizem Kayki-Mutlu
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
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12
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Everything You Always Wanted to Know about β 3-AR * (* But Were Afraid to Ask). Cells 2019; 8:cells8040357. [PMID: 30995798 PMCID: PMC6523418 DOI: 10.3390/cells8040357] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/26/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022] Open
Abstract
The beta-3 adrenergic receptor (β3-AR) is by far the least studied isotype of the beta-adrenergic sub-family. Despite its study being long hampered by the lack of suitable animal and cellular models and inter-species differences, a substantial body of literature on the subject has built up in the last three decades and the physiology of β3-AR is unraveling quickly. As will become evident in this work, β3-AR is emerging as an appealing target for novel pharmacological approaches in several clinical areas involving metabolic, cardiovascular, urinary, and ocular disease. In this review, we will discuss the most recent advances regarding β3-AR signaling and function and summarize how these findings translate, or may do so, into current clinical practice highlighting β3-AR’s great potential as a novel therapeutic target in a wide range of human conditions.
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13
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Okeke K, Angers S, Bouvier M, Michel MC. Agonist-induced desensitisation of β 3 -adrenoceptors: Where, when, and how? Br J Pharmacol 2019; 176:2539-2558. [PMID: 30809805 DOI: 10.1111/bph.14633] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/27/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022] Open
Abstract
β3 -Adrenoceptor agonists have proven useful in the treatment of overactive bladder syndrome, but it is not known whether their efficacy during chronic administration may be limited by receptor-induced desensitisation. Whereas the β2 -adrenoceptor has phosphorylation sites that are important for desensitisation, the β3 -adrenoceptor lacks these; therefore, it had been assumed that β3 -adrenoceptors are largely resistant to agonist-induced desensitisation. While all direct comparative studies demonstrate that β3 -adrenoceptors are less susceptible to desensitisation than β2 -adrenoceptors, desensitisation of β3 -adrenoceptors has been observed in many models and treatment settings. Chimeric β2 - and β3 -adrenoceptors have demonstrated that the C-terminal tail of the receptor plays an important role in the relative resistance to desensitisation but is not the only relevant factor. While the evidence from some models, such as transfected CHO cells, is inconsistent, it appears that desensitisation is observed more often after long-term (hours to days) than short-term (minutes to hours) agonist exposure. When it occurs, desensitisation of β3 -adrenoceptors can involve multiple levels including down-regulation of its mRNA and the receptor protein and alterations in post-receptor signalling events. The relative contributions of these mechanistic factors apparently depend on the cell type under investigation. Which if any of these factors is applicable to the human urinary bladder remains to be determined. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Katerina Okeke
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
| | - Stephane Angers
- Leslie Dan Faculty of Pharmacy and Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, QC, Canada
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
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Ellenbroek JH, Arioglu Inan E, Michel MC. A systematic review of urinary bladder hypertrophy in experimental diabetes: Part 2. Comparison of animal models and functional consequences. Neurourol Urodyn 2018; 37:2346-2360. [DOI: 10.1002/nau.23786] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/03/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Johanne H. Ellenbroek
- Department of Internal Medicine; Leiden University Medical Centre; Leiden The Netherlands
| | | | - Martin C. Michel
- Department of Pharmacology; Johannes Gutenberg University; Mainz Germany
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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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Michel MC, Korstanje C. β3-Adrenoceptor agonists for overactive bladder syndrome: Role of translational pharmacology in a repositioning clinical drug development project. Pharmacol Ther 2016; 159:66-82. [PMID: 26808167 DOI: 10.1016/j.pharmthera.2016.01.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
β3-Adrenoceptor agonists were originally considered as a promising drug class for the treatment of obesity and/or type 2 diabetes. When these development efforts failed, they were repositioned for the treatment of the overactive bladder syndrome. Based on the example of the β3-adrenoceptor agonist mirabegron, but also taking into consideration evidence obtained with ritobegron and solabegron, we discuss challenges facing a translational pharmacology program accompanying clinical drug development for a first-in-class molecule. Challenges included generic ones such as ligand selectivity, species differences and drug target gene polymorphisms. Challenges that are more specific included changing concepts of the underlying pathophysiology of the target condition while clinical development was under way; moreover, a paucity of public domain tools for the study of the drug target and aspects of receptor agonists as drugs had to be addressed. Nonetheless, a successful first-in-class launch was accomplished. Looking back at this translational pharmacology program, we conclude that a specifically tailored and highly flexible approach is required. However, several of the lessons learned may also be applicable to translational pharmacology programs in other indications.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
| | - Cees Korstanje
- Department of Drug Discovery Science & Management-Europe, Astellas Pharma Europe R&D, Leiden, The Netherlands
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17
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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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18
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Cernecka H, Sand C, Michel MC. The odd sibling: features of β3-adrenoceptor pharmacology. Mol Pharmacol 2014; 86:479-84. [PMID: 24890609 DOI: 10.1124/mol.114.092817] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
β3-Adrenoceptor agonists have recently been introduced for the treatment of overactive urinary bladder syndrome. Their target, the β3-adrenoceptor, was discovered much later than β1- and β2-adrenoceptors and exhibits unique properties which make extrapolation of findings from the other two subtypes difficult and the β3-adrenoceptor a less-understood subtype. This article discusses three aspects of β3-adrenoceptor pharmacology. First, the ligand-recognition profile of β3-adrenoceptors differs considerably from that of the other two subtypes, i.e., many antagonists considered as nonselective actually are β3-sparing, including propranolol or nadolol. Many agonists and antagonists classically considered as being β3-selective actually are not, including BRL 37,344 ((±)-(R*,R*)-[4-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]propyl]phenoxy] acetic acid sodium hydrate) or SR 59,230 (3-(2-ethylphenoxy)-[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2S)-2-propanol oxalate). Moreover, the binding pocket apparently differs between the human and rodent β3-adrenoceptor, yielding considerable species differences in potency. Second, the expression pattern of β3-adrenoceptors is more restricted than that of other subtypes, particularly in humans; this makes extrapolation of rodent findings to the human situation difficult, but it may result in a smaller potential for side effects. The role of β3-adrenoceptor gene polymorphisms has insufficiently been explored and may differ even between primate species. Third, β3-adrenoceptors lack the phosphorylation sites involved in agonist-induced desensitization of the other two subtypes. Thus, they exhibit downregulation and/or desensitization in some, but not other, cell types and tissues. When desensitization occurs, it most often is at the level of mRNA or signaling molecule expression. All three of these factors have implications for future studies to better understand the β3-adrenoceptor as a novel pharmacological target.
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Affiliation(s)
- Hana Cernecka
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands (H.C.); Department of Pharmacology, University of Duisburg-Essen, Essen, Germany (C.S.); and Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany (M.C.M.)
| | - Carsten Sand
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands (H.C.); Department of Pharmacology, University of Duisburg-Essen, Essen, Germany (C.S.); and Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany (M.C.M.)
| | - Martin C Michel
- Department of Molecular Pharmacology, University of Groningen, Groningen, The Netherlands (H.C.); Department of Pharmacology, University of Duisburg-Essen, Essen, Germany (C.S.); and Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany (M.C.M.)
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19
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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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20
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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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21
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Dal Monte M, Casini G, Filippi L, Nicchia GP, Svelto M, Bagnoli P. Functional involvement of β3-adrenergic receptors in melanoma growth and vascularization. J Mol Med (Berl) 2013; 91:1407-19. [PMID: 23907236 DOI: 10.1007/s00109-013-1073-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 07/18/2013] [Accepted: 07/22/2013] [Indexed: 01/04/2023]
Abstract
UNLABELLED β-adrenergic signaling is thought to facilitate cancer progression and blockade of β-adrenergic receptors (β-ARs) may slow down tumor growth. A possible role of β3-ARs in tumor growth has not been investigated so far and the lack of highly specific antagonists makes difficult the evaluation of this role. In the present study, β3-AR expression in mouse B16F10 melanoma cells was demonstrated and the effects of two widely used β3-AR blockers, SR59230A and L-748,337, were evaluated in comparison with propranolol, a β1-/β2-AR blocker with poor affinity for β3-ARs, and with siRNAs targeting specific β-ARs. Both SR59230A and L-748,337 reduced cell proliferation and induced apoptosis, likely through the involvement of the inducible isoform of nitric oxide synthase. In addition, hypoxia upregulated β3-ARs and vascular endothelial growth factor (VEGF) in B16F10 cells, whereas SR59230A or L-748,337 prevented the hypoxia-induced VEGF upregulation. Melanoma was induced in mice by inoculation of B16F10 cells. Intra-tumor injections of SR59230A or L-748,337 significantly reduced melanoma growth by reducing cell proliferation and stimulating apoptosis. SR59230A or L-748,337 treatment also resulted in significant decrease of the tumor vasculature. The decrease in tumor vasculature was due to apoptosis of endothelial cells and not to downregulation of angiogenic factors. These results demonstrate that SR59230A and L-748,337 significantly inhibit melanoma growth by reducing tumor cell proliferation and activating tumor cell death. In addition, both drugs reduce tumor vascularization by inducing apoptosis of endothelial cells. Together, these findings indicate β3-ARs as promising, novel targets for anti-cancer therapy. KEY MESSAGE β3-ARs are expressed in B16F10 melanoma cells β3-ARs are involved in B16F10 cell proliferation and apoptosis Reduced β3-AR function decreases the growth of melanoma induced by B16F10 cell inoculation Drugs targeting β3-ARs reduce tumor vasculature β3-ARs can be regarded as promising, novel targets for anti-cancer therapy.
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Affiliation(s)
- Massimo Dal Monte
- Department of Biology, University of Pisa, via San Zeno, 31, 56127, Pisa, Italy
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22
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Agonist-induced desensitization of human β3-adrenoceptors expressed in human embryonic kidney cells. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:843-51. [PMID: 23756578 DOI: 10.1007/s00210-013-0891-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 05/31/2013] [Indexed: 01/08/2023]
Abstract
β3-Adrenoceptors are resistant to agonist-induced desensitization in some cell types but susceptible in others including transfected human embryonic kidney (HEK) cells. Therefore, we have studied cellular and molecular changes involved in agonist-induced β3-adrenoceptor desensitization in HEK cells. Cells were treated with isoprenaline or forskolin, and following wash-out, cyclic adenosine monophosphate (cAMP) accumulation in response to freshly added agonist was quantified. Receptor and G protein expression were quantified by radioligand binding and immunoblot experiments, respectively. Treatment with isoprenaline induced a concentration- and time-dependent desensitization of cAMP accumulation in response to freshly added isoprenaline. This functional desensitization primarily consisted of reduced maximum responses with little change of agonist potency. Maximum desensitization was achieved by pre-treatment with 10 μM isoprenaline for 24 h. It was not accompanied by changes in β3-adrenoceptor density as assessed in saturation radioligand-binding studies. The desensitization was associated with a small reduction in immunoreactivity for α-subunits for Gs and Gi1, whereas that for Gi2, Gi3, and Gq/11 was not significantly altered. In cells treated with pertussis toxin, isoprenaline-induced cAMP accumulation as well as desensitization by isoprenaline pre-treatment remained unchanged. Isoprenaline pre-treatment also reduced forskolin-induced cAMP accumulation; conversely, pre-treatment with forskolin caused a similar desensitization of isoprenaline-induced cAMP accumulation. We conclude that agonist-induced β3-adrenoceptor desensitization in HEK cells does not involve reduced receptor numbers and small, if any, reduction of Gs expression; changes at the level of adenylyl cyclase function can fully explain this desensitization.
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Igawa Y, Michel MC. Pharmacological profile of β3-adrenoceptor agonists in clinical development for the treatment of overactive bladder syndrome. Naunyn Schmiedebergs Arch Pharmacol 2012; 386:177-83. [PMID: 23263450 DOI: 10.1007/s00210-012-0824-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 12/06/2012] [Indexed: 12/28/2022]
Abstract
β(3)-Adrenoceptor agonists are an emerging drug class for the treatment of the overactive bladder syndrome, and clinical proof-of-concept data have been obtained for three representatives of this class, mirabegron, ritobegron, and solabegron. We review here the pharmacological profile of these three drugs and discuss the potential clinical relevance of differences between them. In the absence of direct comparative studies, it appears that all three are strong agonists selective for β(3)- vs. β(1)- and β(2)-adrenoceptors in studies with cloned receptor subtypes. The potency of these agonists may be species-dependent, with all three having high potency in the human detrusor. All three agonists were effective in one or more animal models of bladder dysfunction, which typically involved reductions of micturition frequency. Agonist doses effective for bladder function lowered blood pressure in some cases, but the relevance of this for clinical use is difficult to determine due to species differences in the importance of cardiovascular β(3)-adrenoceptors. While limited effects on other organ systems are expected for β(3)-adrenoceptor agonists, this requires further investigation.
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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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Igawa Y, Schneider T, Yamazaki Y, Tatemichi S, Homma Y, Nishizawa O, Michel MC. Functional investigation of β-adrenoceptors in human isolated detrusor focusing on the novel selective β3-adrenoceptor agonist KUC-7322. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:759-67. [PMID: 22644105 DOI: 10.1007/s00210-012-0763-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 05/15/2012] [Indexed: 12/23/2022]
Abstract
This study aimed to characterize the β-adrenoceptor (β-AR) subtype mediating relaxation of isolated human bladder strips and to explore relaxation by the novel β3-AR-selective agonist KUC-7322 for its relaxant effect on the human isolated detrusor and for its effect on the carbachol (CCh)-induced contractile response. In two parallel studies, relaxation of isolated human bladder strips was tested for the β-AR agonists isoproterenol, clenbuterol, BRL 37344, and KUC-7322. For the isoproterenol and KUC-7322 responses, antagonism by CGP 20712A, ICI 118551, and SR59230A was determined. The potency and efficacy of the reference agonists for detrusor relaxation was in line with their known β3-AR activity. KUC-7322 relative to isoproterenol was a full agonist with a pEC(50) of 5.95 ± 0.09 and 5.92 ± 0.11 in the two studies. SR59230A exhibited antagonism of the expected potency against isoproterenol (apparent pK (B) 7.2) but not against KUC-7322. Neither isoproterenol nor KUC-7322 nor forskolin significantly attenuated CCh-induced contraction. These results suggest that KUC-7322 displays full agonistic activity in relaxing the human detrusor without inhibiting the contraction induced by cholinergic stimulation. These characteristics, if proven in vivo, may be beneficial for the treatment of overactive bladder, as increased bladder capacity with a negligible effect on voiding contractions may be anticipated.
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Affiliation(s)
- Yasuhiko Igawa
- Department of Continence Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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26
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Aragón JP, Condit ME, Bhushan S, Predmore BL, Patel SS, Grinsfelder DB, Gundewar S, Jha S, Calvert JW, Barouch LA, Lavu M, Wright HM, Lefer DJ. Beta3-adrenoreceptor stimulation ameliorates myocardial ischemia-reperfusion injury via endothelial nitric oxide synthase and neuronal nitric oxide synthase activation. J Am Coll Cardiol 2012; 58:2683-91. [PMID: 22152956 DOI: 10.1016/j.jacc.2011.09.033] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 09/09/2011] [Accepted: 09/13/2011] [Indexed: 11/18/2022]
Abstract
OBJECTIVES This paper examined whether nebivolol protects the heart via nitric oxide (NO) synthase and NO-dependent signaling in an in vivo model of acute myocardial infarction. BACKGROUND Beta(3)-adrenergic receptor (AR) activation promotes endothelial nitric oxide synthase (eNOS) activity and NO bioavailability. We hypothesized that specific beta(3)-AR agonists would attenuate myocardial ischemia-reperfusion (MI/R) injury via eNOS activation and increased NO bioavailability. METHODS Mice were subjected to 45 min of myocardial ischemia in vivo followed by 24 h of reperfusion (R). Nebivolol (500 ng/kg), CL 316243 (1 μg/kg), BRL-37344 (1 μg/kg), or vehicle (VEH) was administered at the time of R. Myocardial area-at-risk (AAR) and infarct size (INF)/AAR was measured at 24 h of R. Cardiac tissue and plasma were collected to evaluate eNOS phosphorylation, neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase expression, and nitrite and nitrosothiol levels. RESULTS Nebivolol (500 ng/kg) reduced INF/AAR by 37% (p < 0.001 vs. VEH) and serum troponin-I levels from 41 ± 4 ng/ml to 25 ± 4 ng/ml (p < 0.05 vs. VEH). CL 316243 and BRL-37344 reduced INF by 39% and 42%, respectively (p < 0.001 vs. VEH). Nebivolol and CL 316243 increased eNOS phosphorylation at Ser-1177 (p < 0.05 vs. VEH) and increased nitrite and total nitrosylated protein levels. Nebivolol and CL 316243 significantly increased myocardial nNOS expression. Nebivolol failed to reduce INF after MI/R in beta(3)-AR (-/-), eNOS(-/-), and in nNOS(-/-) mice. CONCLUSIONS Our results indicate that beta(3)-AR agonists protect against MI/R injury. Furthermore, the cardioprotective effects of beta(3)-AR agonists are mediated by rapid eNOS and nNOS activation and increased NO bioavailability.
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Affiliation(s)
- Juan P Aragón
- Department of Surgery, Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, Georgia 30308, USA
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27
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Michel MC, Ochodnicky P, Homma Y, Igawa Y. β-adrenoceptor agonist effects in experimental models of bladder dysfunction. Pharmacol Ther 2011; 131:40-9. [PMID: 21510978 DOI: 10.1016/j.pharmthera.2011.03.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 03/25/2011] [Indexed: 12/17/2022]
Abstract
β-adrenoceptor stimulation can enhance the storage function of the urinary bladder by acting on detrusor smooth muscle tone, mediator release from the urothelium and/or afferent nerve activity. In humans this may occur predominantly if not exclusively via the β₃-subtype. The effects of β-adrenoceptor agonists including several β₃-selective agonists have been studied in vitro and in vivo, in healthy animals of both genders and various age groups and in a wide range of animal (mostly rat) models of genetic or acquired bladder dysfunction. Such models included bladder irritation by intravesical instillation of acetic acid or prostaglandin E₂, bladder outlet obstruction, stroke, diabetes, spontaneously hypertensive rats, and NO synthase inhibition. Across all of these models β-adrenoceptor agonists had effects consistent with improved bladder storage function. β₃-adrenoceptor effects are resistant to agonist-induced desensitization in many cell types, but whether this also applies to the human bladder is unknown. The efficacy of β-adrenoceptor agonists appears to be largely unaffected by common polymorphisms of the β₃-adrenoceptor gene. Taken together these findings suggest that β₃-adrenoceptor agonists may become useful drugs for the treatment of bladder storage dysfunction, a view supported by recent phase III clinical studies for one such agent, mirabegron.
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Affiliation(s)
- Martin C Michel
- Dept. Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, The Netherlands.
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28
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Frazier EP, Michel-Reher MB, van Loenen P, Sand C, Schneider T, Peters SLM, Michel MC. Lack of evidence that nebivolol is a β₃-adrenoceptor agonist. Eur J Pharmacol 2010; 654:86-91. [PMID: 21172342 DOI: 10.1016/j.ejphar.2010.11.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 11/09/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
Abstract
Nebivolol is a selective β₁-adrenoceptor antagonist which, in addition, displays endothelium-dependent vasodilating properties in humans and other species. β₃-adrenoceptors have been proposed to be a molecular target of nebivolol-induced vasodilatation. Therefore, we have investigated possible β₃-adrenoceptor agonism by nebivolol for relaxation of the human and rat urinary bladder (prototypical β₃-adrenoceptor-mediated responses) as well as for cAMP accumulation in Chinese hamster ovary cells stably transfected with the human β-adrenoceptor subtypes. Nebivolol concentration-dependently relaxed both human and rat isolated urinary bladder strips but with low potency, similar to that reported for vasodilatation. However, nebivolol-induced bladder relaxation in either species was not inhibited by the β₃-adrenoceptor antagonist SR 59,230A (10μM), although this compound inhibited the isoprenaline-induced relaxation with the expected potency. In radioligand binding studies nebivolol had lower affinity for human β₃-adrenoceptors than the other two β-adrenoceptor subtypes, but this low affinity was in line with its potency to relax the bladder or isolated blood vessels. In functional studies nebivolol even in high concentrations did not stimulate cAMP formation via any of the three cloned human β-adrenoceptors or in rat bladder smooth muscle cells. Taken together these data demonstrate that nebivolol can relax not only vascular but also urinary bladder smooth muscle. However, they do not support the hypothesis that nebivolol is an agonist at cloned human β₃-adrenoceptors or in rat or human urinary bladder.
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Affiliation(s)
- Elfaridah P Frazier
- Department of Pharmacology and Pharmacotherapy, University of Amsterdam, Meibergdreef 15, Amsterdam, The Netherlands
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29
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Hamdani N, Borbély A, Veenstra SPGR, Kooij V, Vrydag W, Zaremba R, Dos Remedios C, Niessen HWM, Michel MC, Paulus WJ, Stienen GJM, van der Velden J. More severe cellular phenotype in human idiopathic dilated cardiomyopathy compared to ischemic heart disease. J Muscle Res Cell Motil 2010; 31:289-301. [PMID: 21132354 PMCID: PMC3005110 DOI: 10.1007/s10974-010-9231-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 11/19/2010] [Indexed: 01/08/2023]
Abstract
Activation of the β-adrenergic receptor (βAR) pathway is the main mechanism of the heart to increase cardiac output via protein kinase A (PKA)-mediated phosphorylation of cellular target proteins, and perturbations therein may contribute to cardiac dysfunction in heart failure. In the present study a comprehensive analysis was made of mediators of the βAR pathway, myofilament properties and cardiac structure in patients with idiopathic (IDCM; n = 13) and ischemic (ISHD; n = 10) cardiomyopathy in comparison to non-failing hearts (donor; n = 10) for the following parameters: βAR density, G-coupled receptor kinases 2 and 5, stimulatory and inhibitory G-proteins, phosphorylation of myofilament targets of PKA, protein phosphatase 1, phospholamban, SERCA2a and single myocyte contractility. All parameters exhibited the expected alterations of heart failure, but for most of them the extent of alteration was greater in IDCM than in ISHD. Histological analysis also revealed higher collagen in IDCM compared to ISHD. Alterations in the βAR pathway are more pronounced in IDCM than in ISHD and may reflect sequential changes in cellular protein composition and function. Our data indicate that cellular dysfunction is more severe in IDCM than in ISHD.
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Affiliation(s)
- Nazha Hamdani
- Institute for Cardiovascular Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands
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30
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Schneider T, Michel MC. Can [I]-Iodocyanopindolol Label β(3)-Adrenoceptors in Rat Urinary Bladder? Front Pharmacol 2010; 1:128. [PMID: 21734891 PMCID: PMC3124131 DOI: 10.3389/fphar.2010.00128] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 09/23/2010] [Indexed: 11/16/2022] Open
Abstract
β3-Adrenoceptors have been demonstrated to mediate urinary bladder smooth muscle relaxation but proof of their expression at the protein level has been missing because of lack of suitable antibodies or radioligands. As among various available radioligands [125I]-iodocyanopindolol ([125I]-ICYP) exhibited the smallest problems in labeling cloned human β3-adrenoceptors in previous studies, we have explored its suitability to label β3-adrenoceptors in rat urinary bladder in saturation and competition radioligand binding experiments. Rat lung was used as an internal control and exhibited all characteristics expected from this tissue with regard to β1/β2-adrenoceptor labeling. Saturation and competition binding studies with [125I]-ICYP in rat bladder yielded saturable binding sites with an affinity compatible with β3-adrenoceptors. In competition experiments various agonists and antagonists largely exhibited a profile compatible with a population consisting largely of β3-adrenoceptors. However, the binding competition properties of ICI 118,551 and SR 59,230A were not easily explained by the idea of labeling a homogeneous β3-adrenoceptor population but interpretation of the data was limited by a high degree of non-specific binding in [125I]-ICYP concentrations required to label the receptors. We conclude that [125I]-ICYP can be used to label tissue β3-adrenoceptors but results obtained with this ligand have to be interpreted with caution.
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Affiliation(s)
- Tim Schneider
- Department of Medicine, University of Essen Essen, Germany
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31
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Limberg BJ, Andersson KE, Aura Kullmann F, Burmer G, de Groat WC, Rosenbaum JS. β-Adrenergic receptor subtype expression in myocyte and non-myocyte cells in human female bladder. Cell Tissue Res 2010; 342:295-306. [PMID: 20953633 DOI: 10.1007/s00441-010-1053-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 09/08/2010] [Indexed: 12/15/2022]
Abstract
β(3)-Adrenergic receptor agonists are currently under clinical development for the treatment of overactive bladder, a condition that is prevalent in postmenopausal women. These agents purportedly relax bladder smooth muscle through a direct action at the myocyte β(3)-receptor. The aim of this study was to examine the expression of the individual beta-adrenergic receptors in full thickness sections from ageing human female bladder. We obtained a series of rabbit polyclonal antibodies generated against each of the three β-adrenergic receptors, and validated their receptor specificity in CHOK1 cells expressing each of the individual receptors. Immunostaining for β(1), β(2), and β(3) were each more prominent in the urothelium than in the detrusor, with all receptors expressed in the same cell types, indicating co-expression of all three receptors throughout the urothelium in addition to the detrusor. Staining of all receptors was also observed in suburothelial myofibroblast-like cells, intramural ganglion cells, and in Schwann cells of intramural nerves. The β(3)-receptor in the human urothelium appears to be functional, as two different selective β(3)-receptor agonists, TAK677 and BRL37344, stimulate cAMP formation in URO tsa cells. Densitometry analysis indicates a persistent expression of all receptors throughout the bladder with increasing age, with the exception of the β(2)-receptor in the urothelium of the trigone, which appears to decrease slightly in older women. These data indicate that β(3)-receptor expression is maintained with age, but may function in concert with other β-receptors. Activation of the myocyte receptor may be influenced by action on non-myocyte structures including the intramural ganglion cells and myofibroblasts.
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Affiliation(s)
- Brian J Limberg
- Women's Health New Business Development, Procter & Gamble Pharmaceuticals now Warner Chilcott Pharmaceuticals Inc., Mason, OH, USA.
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32
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Moens AL, Yang R, Watts VL, Barouch LA. Beta 3-adrenoreceptor regulation of nitric oxide in the cardiovascular system. J Mol Cell Cardiol 2010; 48:1088-95. [PMID: 20184889 DOI: 10.1016/j.yjmcc.2010.02.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 12/08/2009] [Accepted: 02/12/2010] [Indexed: 11/18/2022]
Abstract
The presence of a third beta-adrenergic receptor (beta 3-AR) in the cardiovascular system has challenged the classical paradigm of sympathetic regulation by beta1- and beta2-adrenergic receptors. While beta 3-AR's role in the cardiovascular system remains controversial, increasing evidence suggests that it serves as a "brake" in sympathetic overstimulation - it is activated at high catecholamine concentrations, producing a negative inotropic effect that antagonizes beta1- and beta2-AR activity. The anti-adrenergic effects induced by beta 3-AR were initially linked to nitric oxide (NO) release via endothelial NO synthase (eNOS), although more recently it has been shown under some conditions to increase NO production in the cardiovascular system via the other two NOS isoforms, namely inducible NOS (iNOS) and neuronal NOS (nNOS). We summarize recent findings regarding beta 3-AR effects on the cardiovascular system and explore its prospective as a therapeutic target, particularly focusing on its emerging role as an important mediator of NO signaling in the pathogenesis of cardiovascular disorders.
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Affiliation(s)
- An L Moens
- Johns Hopkins University School of Medicine, Division of Cardiology, Baltimore, MD 21205, USA
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33
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Barendrecht MM, Frazier EP, Vrydag W, Alewijnse AE, Peters SLM, Michel MC. The effect of bladder outlet obstruction on alpha1- and beta-adrenoceptor expression and function. Neurourol Urodyn 2009; 28:349-55. [PMID: 19034955 DOI: 10.1002/nau.20642] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
AIMS To explore possible changes in expression and/or function of alpha(1)- and beta-adrenoceptor subtypes as a cause for bladder dysfunction in a rat model of bladder outlet obstruction (BOO). METHODS BOO was induced in rats by partial urethral ligature. Contraction and relaxation experiments were performed with isolated bladder strips from BOO, sham-operated and non-operated (control) rats 7 days after BOO induction. mRNA expression of alpha(1)- and beta-adrenoceptor subtypes was assessed by quantitative real-time PCR. RESULTS Receptor-independent contraction or relaxation did not differ between BOO and sham rats. The alpha(1)-agonists methoxamine and A-61,603 caused only weak contraction without major differences between groups. Against KCl-induced tone, the beta-adrenoceptor agonists noradrenaline and isoprenaline caused similar relaxation in BOO and sham rats, whereas relaxation in response to the beta(3)-selective BRL 37,344 was attenuated. Against passive tension, noradrenaline induced relaxation in sham and control rats; in contrast, noradrenaline induced contraction at low concentrations and relaxation at high concentrations in BOO rats. The contraction component was abolished by the alpha(1)-antagonist prazosin. The mRNA expression of alpha(1D)-adrenoceptors was increased in BOO, whereas none of the other receptor mRNAs were up-regulated. CONCLUSIONS In a rat BOO model, weak contraction responses to alpha(1)-agonists and relaxation responses to beta-agonists are not altered to a major extent. Nevertheless, relaxation responses to the endogenous agonist noradrenaline are turned into alpha(1)-adrenoceptor-mediated contraction responses in BOO, possibly due to an up-regulation of alpha(1D)-adrenoceptors.
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Affiliation(s)
- Maurits M Barendrecht
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, Amsterdam, The Netherlands
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34
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Lack of specificity of antibodies directed against human beta-adrenergic receptors. Naunyn Schmiedebergs Arch Pharmacol 2009. [DOI: 10.1007/s00210-009-0412-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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35
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Pradidarcheep W, Stallen J, Labruyère WT, Dabhoiwala NF, Michel MC, Lamers WH. Lack of specificity of commercially available antisera against muscarinergic and adrenergic receptors. Naunyn Schmiedebergs Arch Pharmacol 2009; 379:397-402. [PMID: 19198807 DOI: 10.1007/s00210-009-0393-0] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 01/03/2009] [Indexed: 10/21/2022]
Abstract
Commercially available antisera against five subtypes of muscarinic receptors and nine subtypes of adrenoceptors showed highly distinct immunohistochemical staining patterns in rat ureter and stomach. However, using the M(1-4) muscarinic receptor subtypes and alpha(2B)-, beta(2)-, and beta(3)-adrenoceptors as examples, Western blots with membranes prepared from cell lines stably expressing various subtypes of muscarinic receptors or adrenoceptors revealed that each of the antisera recognized a set of proteins that differed between the cell lines used but lacked specificity for the claimed target receptor. We propose that receptor antibodies need better validation before they can reliably be used.
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Affiliation(s)
- Wisuit Pradidarcheep
- Department of Anatomy, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand
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36
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Hamdani N, van der Velden J. Lack of specificity of antibodies directed against human beta-adrenergic receptors. Naunyn Schmiedebergs Arch Pharmacol 2009; 379:403-7. [PMID: 19156400 DOI: 10.1007/s00210-009-0392-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 01/02/2009] [Indexed: 11/25/2022]
Abstract
The present study was designed to investigate if antibodies against beta-adrenergic receptors (betaARs) can be used to determine expression of betaAR in human myocardium. Western blotting was performed to investigate the specificity of antibodies directed against beta(1)AR and beta(2)AR in human left ventricular tissue. A comparison was made between cardiac tissue from patients with idiopathic dilated cardiomyopathy and ischemic heart disease and nonfailing donors. The antibodies directed against beta(1)AR and beta(2)AR recognized several protein bands at different molecular weights. Moreover, both antibodies also recognized multiple proteins in Chinese hamster ovary cells expressing beta(1)AR, beta(2)AR, and even beta(3)AR. betaAR antibodies are not specific and are not suited to study expression of betaAR in human myocardium.
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MESH Headings
- Animals
- Antibodies/immunology
- Antibody Specificity/immunology
- Blotting, Western
- CHO Cells
- Cricetinae
- Cricetulus
- Heart Ventricles/chemistry
- Humans
- Receptors, Adrenergic, beta/analysis
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/immunology
- Receptors, Adrenergic, beta-1/analysis
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/immunology
- Receptors, Adrenergic, beta-2/analysis
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/immunology
- Receptors, Adrenergic, beta-3/analysis
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/immunology
- Transfection
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Affiliation(s)
- Nazha Hamdani
- Laboratory for Physiology, Institute for Cardiovascular Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
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Vrydag W, Alewijnse AE, Michel MC. Do gene polymorphisms alone or in combination affect the function of human beta3-adrenoceptors? Br J Pharmacol 2009; 156:127-34. [PMID: 19133996 PMCID: PMC2697764 DOI: 10.1111/j.1476-5381.2008.00014.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 08/20/2008] [Accepted: 08/22/2008] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE beta(3)-Adrenoceptors mediate many important physiological functions, for example, in the urinary bladder. The corresponding gene is polymorphic, and the W64R (Trp64Arg) single nucleotide polymorphism has been associated with disease states such as obesity, type 2 diabetes and bladder dysfunction. While these clinical data suggest that the 64R variant is hypofunctional, previous in vitro studies in which this variant was generated by site-directed mutagenesis and subsequent transfection have not consistently confirmed this. EXPERIMENTAL APPROACH We transfected the wild-type human beta(3)-adrenoceptor and the 64R variant and also the more recently discovered 265M and 306F variants as well as 64R/265M and 64R/306F double mutants into human embryonic kidney cells and selected clones expressing the receptors at a density of about 100 fmol mg protein(-1). Receptor activation was measured by cAMP accumulation and ligand affinity by radioligand binding. Desensitisation was assessed as alterations of cAMP responses after prolonged agonist treatment. KEY RESULTS Neither mutated receptor exhibited alterations in efficacy or potency for cAMP accumulation for any of five agonists (isoprenaline, noradrenaline, YM 178, FK 4664, CGP 12 177). In competition binding studies, the mutations did not affect the ability of any agonist to bind to the receptor. Wild-type receptors and the 64R variant exhibited similar isoprenaline-induced functional desensitization during a 24 h treatment. CONCLUSIONS AND IMPLICATIONS None of the polymorphisms tested here significantly altered the interaction of isoprenaline, noradrenaline, YM 178, FK 4664 or CGP 12 177 with the human beta(3)-adrenoceptor when expressed at near physiological levels in a human cell line.
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Affiliation(s)
- Wim Vrydag
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Arch JRS. The discovery of drugs for obesity, the metabolic effects of leptin and variable receptor pharmacology: perspectives from beta3-adrenoceptor agonists. Naunyn Schmiedebergs Arch Pharmacol 2008; 378:225-40. [PMID: 18612674 DOI: 10.1007/s00210-008-0271-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2008] [Accepted: 02/05/2008] [Indexed: 12/12/2022]
Abstract
Although beta3-adrenoceptor (beta3AR) agonists have not become drugs for the treatment of obesity or diabetes, they offer perspectives on obesity drug discovery, the physiology of energy expenditure and receptor pharmacology. beta3AR agonists, some of which also stimulate other betaARs in humans, selectively stimulate fat oxidation in rodents and humans. This appears to be why they improve insulin sensitivity and reduce body fat whilst preserving lean body mass. Regulatory authorities ask that novel anti-obesity drugs improve insulin sensitivity and reduce mainly body fat. Drugs that act on different targets to stimulate fat oxidation may also offer these benefits. Stimulation of energy expenditure may be easy to detect only when the sympathetic nervous system is activated. Leptin resembles beta3AR agonists in that it increases fat oxidation, energy expenditure and insulin sensitivity. This is partly because it raises sympathetic activity, but it may also promote fat oxidation by directly stimulating muscle leptin receptors. The beta1AR and beta2AR can, like the beta3AR, display atypical pharmacologies. Moreover, the beta3AR can display variable pharmacologies of its own, depending on the radioligand used in binding studies or the functional response measured. Studies on the beta3AR demonstrate both the difficulties of predicting the in vivo effects of agonist drugs from in vitro data and that there may be opportunities for identifying drugs that act at a single receptor but have different profiles in vivo.
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Affiliation(s)
- Jonathan R S Arch
- Clore Laboratory, University of Buckingham, Buckingham, MK18 1EG, UK.
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39
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Michel MC, Barendrecht MM. Physiological and pathological regulation of the autonomic control of urinary bladder contractility. Pharmacol Ther 2008; 117:297-312. [DOI: 10.1016/j.pharmthera.2007.12.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 12/04/2007] [Indexed: 01/10/2023]
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40
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Racké K, Haag S, Bahulayan A, Warnken M. Pulmonary fibroblasts, an emerging target for anti-obstructive drugs. Naunyn Schmiedebergs Arch Pharmacol 2008; 378:193-201. [PMID: 18270687 DOI: 10.1007/s00210-008-0264-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 01/17/2008] [Indexed: 12/28/2022]
Abstract
Fibrotic alterations are part of the airway re-modelling processes observed in asthma and chronic obstructive pulmonary disease. There is increasing evidence that in addition to acute bronchodilatory effects, classical anti-obstructive drugs such as muscarinic antagonists and beta-adrenoceptor agonists may also modulate long-term re-modelling processes. The present review aims to summarise muscarinic and beta-adrenergic effects on pulmonary fibroblasts. Recent experimental evidence demonstrated muscarinic stimulatory effects on pulmonary fibroblasts, and long-term blockade of these pro-fibrotic effects may contribute to the beneficial effects of muscarinic antagonists, as observed particularly for the long-acting muscarinic antagonist tiotropium. On the other hand, beta-adrenoceptor agonists, via activation of adenylyl cyclase, can also exert various inhibitory effects on pulmonary fibroblasts, and these anti-fibrotic effects are mimicked by other agents that cause an increase in intracellular cyclic adenosine monophosphate (cAMP), such as phosphodiesterase inhibitors or EP2 prostanoid receptor agonists. In addition, the role of the extracellular signal-regulated kinase-mitogen-activated protein kinase pathway, protein kinase A and exchange protein activated by cAMP (Epac) and potential interactions between these cellular signalling pathways are discussed.
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Affiliation(s)
- Kurt Racké
- Institute of Pharmacology and Toxicology, University of Bonn, Reuterstrabe 2b, 53113, Bonn, Germany.
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Signal transduction underlying the control of urinary bladder smooth muscle tone by muscarinic receptors and beta-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol 2007; 377:449-62. [PMID: 18060543 PMCID: PMC2480512 DOI: 10.1007/s00210-007-0208-0] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 10/21/2007] [Indexed: 12/17/2022]
Abstract
The normal physiological contraction of the urinary bladder, which is required for voiding, is predominantly mediated by muscarinic receptors, primarily the M3 subtype, with the M2 subtype providing a secondary backup role. Bladder relaxation, which is required for urine storage, is mediated by β-adrenoceptors, in most species involving a strong β3-component. An excessive stimulation of contraction or a reduced relaxation of the detrusor smooth muscle during the storage phase of the micturition cycle may contribute to bladder dysfunction known as the overactive bladder. Therefore, interference with the signal transduction of these receptors may be a viable approach to develop drugs for the treatment of overactive bladder. The prototypical signaling pathway of M3 receptors is activation of phospholipase C (PLC), and this pathway is also activated in the bladder. Nevertheless, PLC apparently contributes only in a very minor way to bladder contraction. Rather, muscarinic-receptor-mediated bladder contraction involves voltage-operated Ca2+ channels and Rho kinase. The prototypical signaling pathway of β-adrenoceptors is an activation of adenylyl cyclase with the subsequent formation of cAMP. Nevertheless, cAMP apparently contributes in a minor way only to β-adrenoceptor-mediated bladder relaxation. BKCa channels may play a greater role in β-adrenoceptor-mediated bladder relaxation. We conclude that apart from muscarinic receptor antagonists and β-adrenoceptor agonists, inhibitors of Rho kinase and activators of BKCa channels may have potential to treat an overactive bladder.
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Myslivecek J, Duysen EG, Lockridge O. Adaptation to excess acetylcholine by downregulation of adrenoceptors and muscarinic receptors in lungs of acetylcholinesterase knockout mice. Naunyn Schmiedebergs Arch Pharmacol 2007; 376:83-92. [PMID: 17805515 DOI: 10.1007/s00210-007-0184-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Accepted: 08/06/2007] [Indexed: 10/22/2022]
Abstract
The acetylcholinesterase knockout mouse has elevated acetylcholine levels due to the complete absence of acetylcholinesterase. Our goal was to determine the adaptive changes in lung receptors that allow these animals to tolerate excess neurotransmitter. The hypothesis was tested that not only muscarinic receptors but also alpha(1)-adrenoceptors and beta-adrenoceptors are downregulated, thus maintaining a proper balance of receptors and accounting for lung function in these animals. The quantity of alpha(1A), alpha(1B), alpha(1D), beta(1), and beta(2)-adrenoceptors and muscarinic receptors was determined by binding of radioligands. G-protein coupling was assessed using pseudo-competition with agonists. Phospholipase C activity was measured by an enzymatic assay. Cyclic AMP (cAMP) content was measured by immunoassay. Muscarinic receptors were decreased to 50%, alpha(1)-adrenoceptors to 23%, and beta-adrenoceptors to about 50% of control. Changes were subtype specific, as alpha(1A), alpha(1B), and beta(2)-adrenoceptors, but not alpha(1D)-adrenoceptor, were decreased. In contrast, receptor signaling into the cell as measured by coupling to G proteins, cAMP content, and PI-phospholipase C activity was the same as in control. This shows that the nearly normal lung function of these animals was explained by maintenance of a correct balance of adrenoceptors and muscarinic receptors. In conclusion, knockout mice have adapted to high concentrations of acetylcholine by downregulating receptors that bind acetylcholine, as well as by downregulating receptors that oppose the action of muscarinic receptors. Tolerance to excess acetylcholine is achieved by reducing the levels of muscarinic receptors and adrenoceptors.
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Affiliation(s)
- Jaromir Myslivecek
- Institute of Physiology, 1st Faculty of Medicine, Charles University, Albertov 5, 12800 Prague, Czech Republic.
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Vrydag W, Michel MC. Tools to study beta3-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol 2007; 374:385-98. [PMID: 17211601 DOI: 10.1007/s00210-006-0127-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 11/22/2006] [Indexed: 12/21/2022]
Abstract
Beta(3)-adrenoceptors mediate some of the effects of catecholamines on tissues such as blood vessels or the urinary bladder and are putative targets for the treatment of diseases such as the overactive bladder syndrome. Progress in the understanding of the presence, function, and regulation of beta(3)-adrenoceptors has been hampered by a lack of highly specific tools. "Classical" beta(3)-adrenoceptor agonists such as BRL 37,344 [(R*, R*)-(+/-)-4[2-[(3-chlorophenyl)-2-hydroxyethyl) amino] propyl] phenoxyacetic acid] and CGP 12,177 [(+/-)-4-(3-t-butylamino-2-hydroxypropoxy)benzimidazol-2-one] are only partial agonists in many settings, have limited selectivity over other beta-adrenoceptor subtypes, and may additionally act on receptors other than beta-adrenoceptors. More efficacious and more selective agonists have been reported and, in some cases, are in clinical development but are not widely available for experimental studies. The widely used antagonist SR 59,230 [3-(2-ethylphenoxy)-1-[(1,S)-1,2,3,4-tetrahydronapth-1-ylamino]-2S-2-propanoloxalate] is not selective for beta(3)-adrenoceptors, at least in humans, and may actually be a partial agonist. Radioligands, which are suitable either for the selective labeling of beta(3)-adrenoceptors or for the nonselective labeling of all beta-adrenoceptor subtypes, are also missing. beta(3)- and beta(1)/beta(2) double knockout mice have been reported, but their usefulness for extrapolations in humans is questionable based upon major differences between humans and rodents with regard to the ligand recognition and expression profiles of beta(3)-adrenoceptors. While the common availability of more selective agonists and antagonists at the beta(3)-adrenoceptor is urgently awaited, the limitations of the currently available tools need to be considered in studies of beta(3)-adrenoceptor for the time being.
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Affiliation(s)
- Wim Vrydag
- Department Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
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