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Gao N, Tsai MH, Chang AN, He W, Chen CP, Zhu M, Kamm KE, Stull JT. Physiological vs. pharmacological signalling to myosin phosphorylation in airway smooth muscle. J Physiol 2017; 595:6231-6247. [PMID: 28749013 PMCID: PMC5621497 DOI: 10.1113/jp274715] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/25/2017] [Indexed: 01/05/2023] Open
Abstract
KEY POINTS Smooth muscle myosin regulatory light chain (RLC) is phosphorylated by Ca2+ /calmodulin-dependent myosin light chain kinase and dephosphorylated by myosin light chain phosphatase (MLCP). Tracheal smooth muscle contains significant amounts of myosin binding subunit 85 (MBS85), another myosin phosphatase targeting subunit (MYPT) family member, in addition to MLCP regulatory subunit MYPT1. Concentration/temporal responses to carbachol demonstrated similar sensitivities for bovine tracheal force development and phosphorylation of RLC, MYPT1, MBS85 and paxillin. Electrical field stimulation releases ACh from nerves to increase RLC phosphorylation but not MYPT1 or MBS85 phosphorylation. Thus, nerve-mediated muscarinic responses in signalling modules acting on RLC phosphorylation are different from pharmacological responses with bath added agonist. The conditional knockout of MYPT1 or the knock-in mutation T853A in mice had no effect on muscarinic force responses in isolated tracheal tissues. MLCP activity may arise from functionally shared roles between MYPT1 and MBS85, resulting in minimal effects of MYPT1 knockout on contraction. ABSTRACT Ca2+ /calmodulin activation of myosin light chain kinase (MLCK) initiates myosin regulatory light chain (RLC) phosphorylation for smooth muscle contraction with subsequent dephosphorylation for relaxation by myosin light chain phosphatase (MLCP) containing regulatory (MYPT1) and catalytic (PP1cδ) subunits. RLC phosphorylation-dependent force development is regulated by distinct signalling modules involving protein phosphorylations. We investigated responses to cholinergic agonist treatment vs. neurostimulation by electric field stimulation (EFS) in bovine tracheal smooth muscle. Concentration/temporal responses to carbachol demonstrated tight coupling between force development and RLC phosphorylation but sensitivity differences in MLCK, MYPT1 T853, MYPT1 T696, myosin binding subunit 85 (MBS85), paxillin and CPI-17 (PKC-potentiated protein phosphatase 1 inhibitor protein of 17 kDa) phosphorylations. EFS increased force and phosphorylation of RLC, CPI-17 and MLCK. In the presence of the cholinesterase inhibitor neostigmine, EFS led to an additional increase in phosphorylation of MYPT1 T853, MYPT1 T696, MBS85 and paxillin. Thus, there were distinct pharmacological vs. physiological responses in signalling modules acting on RLC phosphorylation and force responses, probably related to degenerate G protein signalling networks. Studies with genetically modified mice were performed. Expression of another MYPT1 family member, MBS85, was enriched in mouse, as well as bovine tracheal smooth muscle. Carbachol concentration/temporal-force responses were similar in trachea from MYPT1SM+/+ , MYPT1SM-/- and the knock-in mutant mice containing nonphosphorylatable MYPT1 T853A with no differences in RLC phosphorylation. Thus, MYPT1 T853 phosphorylation was not necessary for regulation of RLC phosphorylation in tonic airway smooth muscle. Furthermore, MLCP activity may arise from functionally shared roles between MYPT1 and MBS85, resulting in minimal effects of MYPT1 knockout on contraction.
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Affiliation(s)
- Ning Gao
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ming-Ho Tsai
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Present address: Graduate Institute of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, San Ming District, Kaohsiung, Taiwan
| | - Audrey N Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiqi He
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Present address: Cambridge-Suda (CAM-SU) Genomic Resource Center, Soochow University, Suzhou, China
| | - Cai-Ping Chen
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China.,Present address: Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing, PR China
| | - Minsheng Zhu
- Model Animal Research Center and MOE Key Laboratory of Model Animal for Disease Study, Nanjing University, Nanjing, China
| | - Kristine E Kamm
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Hadi T, Douhard R, Dias AMM, Wendremaire M, Pezzè M, Bardou M, Sagot P, Garrido C, Lirussi F. Beta3 adrenergic receptor stimulation in human macrophages inhibits NADPHoxidase activity and induces catalase expression via PPARγ activation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1769-1784. [PMID: 28723418 DOI: 10.1016/j.bbamcr.2017.07.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 06/22/2017] [Accepted: 07/14/2017] [Indexed: 12/22/2022]
Abstract
The beta3 adrenergic receptor (β3-AR) stimulation plays a protective role against preterm labor by blocking myometrial contraction, cytokine production, remodeling and apoptosis. We previously demonstrated that macrophage-induced ROS production in the myometrium was a key element leading to the induction of all these labor-associated features. We thus aimed to investigate if the β3-AR could be expressed in human macrophages and could trigger its protective role in the myometrium by directly inhibiting ROS production. Using lipopolysaccharide (LPS)-stimulated myometrial samples and cell co-culture experiments, we demonstrated that β3-AR stimulation inhibits the activation of the NADPH oxidase, leading to the subsequent inhibition of ROS production by macrophages. This antioxidant effect was associated with a potent anti-inflammatory response in macrophages. Furthermore, we observed that β3-AR leads to the expression of catalase not only in macrophages but also in myometrial cells, thereby preventing the transactivation of myometrial cells by hydrogen peroxide. Pharmacological experiments allowed us to demonstrate that these effects were driven by an Erk1/2-mediated activation of the antioxidant transcription factor PPARγ. These results suggest that β3-AR protective effects in the myometrium could be due to its dual antioxidant properties. Further, the effects observed in a macrophage could highlight new applications in chronic inflammatory diseases.
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Affiliation(s)
- Tarik Hadi
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; NYU Langone Medical Center, Department of Vascular Surgery, New York, NY, USA; Université de Bourgogne, Dijon, France
| | - Romain Douhard
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France
| | - Alexandre M M Dias
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France
| | - Maeva Wendremaire
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France; Centre Hospitalier Universitaire de Dijon, France
| | - Maria Pezzè
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France
| | - Marc Bardou
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France; Centre Hospitalier Universitaire de Dijon, France; INSERM CIC-P 803, Dijon, France
| | - Paul Sagot
- Centre Hospitalier Universitaire de Dijon, France; Service de Gynécologie & Obstétrique, Dijon, France
| | - Carmen Garrido
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France; Anti-cancer Center George-François Leclerc, CGFL, Dijon, France
| | - Frédéric Lirussi
- INSERM, U1231, Lipides Nutrition Cancer, Equipe labélisée Ligue Nationale contre le Cancer, Dijon, France; Université de Bourgogne, Dijon, France; Centre Hospitalier Universitaire de Dijon, France.
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Kochenov АV, Poddubnaya YP, Makedonsky IA, Korogod SМ. Excitability Characteristics of a Urinary Bladder Detrusor Smooth Muscle Cell as a Basis for Choosing Parameters of Rehabilitation Electrostimulation: A Simulation Study. NEUROPHYSIOLOGY+ 2015. [DOI: 10.1007/s11062-015-9504-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Dale PR, Cernecka H, Schmidt M, Dowling MR, Charlton SJ, Pieper MP, Michel MC. The pharmacological rationale for combining muscarinic receptor antagonists and β-adrenoceptor agonists in the treatment of airway and bladder disease. Curr Opin Pharmacol 2014; 16:31-42. [PMID: 24682092 PMCID: PMC4071415 DOI: 10.1016/j.coph.2014.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/03/2014] [Accepted: 03/04/2014] [Indexed: 02/07/2023]
Abstract
Muscarinic receptors increase smooth muscle tone in airways and urinary bladder. β-Adrenoceptors relax smooth muscle tone and oppose muscarinic contraction. Opposition involves transmitter release, signal transduction and receptor expression. This supports the combined use of muscarinic antagonists and β-adrenoceptor agonists.
Muscarinic receptor antagonists and β-adrenoceptor agonists are used in the treatment of obstructive airway disease and overactive bladder syndrome. Here we review the pharmacological rationale for their combination. Muscarinic receptors and β-adrenoceptors are physiological antagonists for smooth muscle tone in airways and bladder. Muscarinic agonism may attenuate β-adrenoceptor-mediated relaxation more than other contractile stimuli. Chronic treatment with one drug class may regulate expression of the target receptor but also that of the opposing receptor. Prejunctional β2-adrenoceptors can enhance neuronal acetylcholine release. Moreover, at least in the airways, muscarinic receptors and β-adrenoceptors are expressed in different locations, indicating that only a combined modulation of both systems may cause dilatation along the entire bronchial tree. While all of these factors contribute to a rationale for a combination of muscarinic receptor antagonists and β-adrenoceptor agonists, the full value of such combination as compared to monotherapy can only be determined in clinical studies.
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Affiliation(s)
- Philippa R Dale
- Department of Pharmacology, Cambridge University, Cambridge, UK
| | - Hana Cernecka
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Martina Schmidt
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Mark R Dowling
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Steven J Charlton
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Michael P Pieper
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany
| | - Martin C Michel
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany; Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
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Sand C, Michel MC. Bradykinin Contracts Rat Urinary Bladder Largely Independently of Phospholipase C. J Pharmacol Exp Ther 2013; 348:25-31. [DOI: 10.1124/jpet.113.208025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Hadi T, Barrichon M, Mourtialon P, Wendremaire M, Garrido C, Sagot P, Bardou M, Lirussi F. Biphasic Erk1/2 activation sequentially involving Gs and Gi signaling is required in beta3-adrenergic receptor-induced primary smooth muscle cell proliferation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1041-51. [PMID: 23388888 DOI: 10.1016/j.bbamcr.2013.01.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 01/02/2013] [Accepted: 01/18/2013] [Indexed: 01/13/2023]
Abstract
The beta3 adrenergic receptor (B3-AR) reportedly induces cell proliferation, but the signaling pathways that were proposed, involving either Gs or Gi coupling, remain controversial. To further investigate the role of G protein coupling in B3-AR induced proliferation, we stimulated primary human myometrial smooth muscle cells with SAR150640 (B3-AR agonist) in the absence or presence of variable G-protein inhibitors. Specific B3-AR stimulation led to an Erk1/2 induced proliferation. We observed that the proliferative effects of B3-AR require two Erk1/2 activation peaks (the first after 3min, the second at 8h). Erk1/2 activation at 3min was mimicked by forskolin (adenylyl-cyclase activator), and was resistant to pertussis toxin (Gi inhibitor), suggesting a Gs protein signaling. This first signaling also required the downstream Gs signaling effectors PKA and Src. However, Erk1/2 activation at 8h turned out to be pertussis toxin-dependent, and PKA-independent, indicating a Gi signaling pathway in which Src and PI3K were required. The pharmacological inhibition of both the Gs and Gi pathway abolished B3-AR-induced proliferation. Altogether, these data indicate that B3-AR-induced proliferation depends on the biphasic activation of Erk1/2 sequentially induced by the Gs/PKA/Src and Gi/Src/PI3K signaling pathways.
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[Acetylcholine induces human detrusor muscle cell proliferation: molecular and pharmacological characterization]. Urologia 2012; 79:102-8. [PMID: 22610841 DOI: 10.5301/ru.2012.9272] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2012] [Indexed: 01/28/2023]
Abstract
INTRODUCTION The purpose of the study is to understand whether the cholinergic stimulation is important, not only in inducing contraction of the detrusor muscle, but also in modulating the proliferation of smooth muscle cells. These results could help to better understand the role of antimuscarinic drugs, which are currently used for the treatment of many urological diseases. PATIENTS AND METHODS Primary cultures were prepared from biopsies of human detrusor muscle of subjects >65 years. From the cell culture set-up for each patient, mRNA was extracted and both the gene expression and the influence of increasing passages on the expression of muscarinic receptor subtypes were evaluated by semi-quantitative and quantitative PCR (RT-PCR and Q-RT-PCR). The rate of cell proliferation induced by cholinergic drugs was assessed by the evaluation of the [3H]-thymidine incorporation. RESULTS The gene expression analysis demonstrated that the range of expression of muscarinic subtypes in human detrusor smooth muscle cells (HDSMCs) is M2 > M3 > M1 > M4 >> M5. The exposure to the cholinergic agonist carbachol induced a concentration-dependent increase in cell proliferation rate. The pharmacological characterization indicated that this effect was mainly mediated by the receptor subtypes M3 and M2. DISCUSSION The cholinergic stimulation led to an increase in HDSMC proliferation, suggesting that this phenomenon might be involved in the pathogenic mechanism through which the cervico-urethral obstruction causes a detrusor hypertrophy, followed by a loss of function. These results could then provide an indication of the use of antimuscarinic drugs in the treatment of lower urinary tract disorders.
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Owen SJ, Massa HH, Rose'Meyer RB. Loss of adenosine A2B receptor mediated relaxant responses in the aged female rat bladder; effects of dietary phytoestrogens. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:539-49. [PMID: 22237834 DOI: 10.1007/s00210-011-0722-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/22/2011] [Indexed: 12/12/2022]
Abstract
This study examined the effect of age, ovariectomy and dietary phytoestrogen ingestion on adenosine A(2B) receptor mediated relaxant responses and mRNA expression of adenosine receptor subtypes in the rat isolated bladder. Female Wistar rats (8 weeks) were anaesthetised and the ovaries were removed (ovx) or left intact (sham). Rats were fed either normal rat chow (soy, phytoestrogens) or a non-soy (phytoestrogen free) diet. Isolated bladder from rats aged 12, 24 or 52 weeks were pre-contracted with 3 μM carbachol prior to a concentration response curve to 5'-(N-ethylcarboxamido) adenosine (NECA) being obtained. In 12-week-old rats, the bladder exhibited enhanced relaxant responses to NECA in soy-fed rats (P < 0.05), whilst at 24 weeks of age, the relaxant responses to NECA were attenuated in all the groups studied except soy-treated sham rat bladders in which the relaxant responses were enhanced. At 52 weeks of age, no relaxant effects were observed in any of the treatment groups and NECA-induced contractile responses occurred. In all bladders, the adenosine A(2B) receptor was the most abundantly expressed. In bladders from young and mature female rats, the mRNA expression of adenosine receptors (A(1), A(2A) and A(2B)) was lowest in the bladder from non-soy-fed ovariectomised animals and the use of phytoestrogens in the diet increased the mRNA expression of these receptors (P < 0.05). While a soy diet improves the relaxant effects to the adenosine analogue via adenosine A(2B) receptors in bladders from younger rats, the benefits are lost with advancing age.
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Affiliation(s)
- Suzzanne J Owen
- School of Medical Sciences, Griffith University, Gold Coast Campus, Queensland, 4222, Australia
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Abstract
A wide range of polymorphisms have been reported in muscarinic receptor subtype genes, mostly in M₁ and M₂ and, to a lesser extent, M₃ receptors. Most studies linking such genetic variability to phenotype have been performed for brain functions, but a more limited amount of information is also available for cardiac and airway function. Unfortunately, for none of the phenotypes under investigation a robust association with genotype has emerged. Moreover, it remains mostly unclear whether a reported association indicates a causative role of the polymorphism under investigation or merely a role as indicator of other polymorphisms affecting expression and/or function of the receptor. Also, most data on genotype-phenotype associations of muscarinic receptor subtypes are based on cross-sectional samples. Mechanistic studies linking polymorphisms to molecular, cellular, and tissue functions are largely missing. Finally, studies on a possible impact of muscarinic receptor polymorphisms on drug responsiveness are also largely missing. Thus, the field of genomics of muscarinic receptor subtypes is still in an early stage and a considerably greater number of studies will be required to judge the role of muscarinic receptor gene variability in physiology, pathophysiology, and drug treatment.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, The Netherlands.
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Witte LPW, de Haas N, Mammen M, Stangeland EL, Steinfeld T, Aiyar J, Michel MC. Muscarinic receptor subtypes and signalling involved in the attenuation of isoprenaline-induced rat urinary bladder relaxation. Naunyn Schmiedebergs Arch Pharmacol 2011; 384:555-63. [PMID: 21947231 PMCID: PMC3220825 DOI: 10.1007/s00210-011-0689-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 08/26/2011] [Indexed: 12/16/2022]
Abstract
β-Adrenoceptors are important mediators of smooth muscle relaxation in the urinary bladder, but the concomitant presence of a muscarinic agonist, e.g., carbachol, can attenuate relaxation responses by reducing potency and/or efficacy of β-adrenoceptor agonists such as isoprenaline. Therefore, the present study was designed to explore the subtypes and signalling pathways of muscarinic receptors involved in the attenuation of isoprenaline-induced isolated rat detrusor preparations using novel subtype-selective receptor ligands. In radioligand binding studies, we characterized BZI to be a M3-sparing muscarinic agonist, providing selective M2 stimulation in rat bladder, and THRX-182087 as a highly M2-selective antagonist. The use of BZI and of THRX-182087 in the presence of carbachol enabled experimental conditions with a selective stimulation of only M2 or M3 receptors, respectively. Confirming previous findings, carbachol attenuated isoprenaline-induced detrusor relaxation. M2-selective stimulation partly mimicked this attenuation, indicating that both M2 and M3 receptors are involved. During M3-selective stimulation, the attenuation of isoprenaline responses was reduced by the phospholipase C inhibitor U 73,122 but not by the protein kinase C inhibitor chelerythrine. We conclude that both M2 and M3 receptors contribute to attenuation of β-adrenoceptor-mediated relaxation of rat urinary bladder; the signal transduction pathway involved in the M3 component of this attenuation differs from that mediating direct contractile effects of M3 receptors.
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Affiliation(s)
- Lambertus P W Witte
- Depts. of Pharmacology and Pharmacotherapy and of Urology, Academic Medical Center, Amsterdam, The Netherlands
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Effect of pre-contraction on β-adrenoceptor-mediated relaxation of rat urinary bladder. World J Urol 2011; 27:711-5. [PMID: 19449014 PMCID: PMC2780656 DOI: 10.1007/s00345-009-0416-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 04/24/2009] [Indexed: 01/25/2023] Open
Abstract
PURPOSE The human physiological bladder contraction is largely mediated by acetylcholine acting on muscarinic receptors, but in pathophysiological settings the relative role of non-cholinergic stimuli gains importance. β-Adrenoceptor agonists are currently in clinical development as treatments for the overactive bladder syndrome. Therefore, we have explored the ability of the β-adrenoceptor agonist isoprenaline to induce rat isolated bladder strip relaxation on pre-contraction with the muscarinic agonist carbachol as compared to bladder tone induced by several non-cholinergic stimuli. METHODS Bladder tone was induced by passive tension, receptor independently by KCl, carbachol, bradykinin or serotonin. Concentration–response curves were generated for relaxation by isoprenaline, and a single concentration of the receptor-independent relaxant forskolin was also tested. RESULTS The various contractile stimuli induced different degrees of bladder tone, but the ability of isoprenaline or forskolin to relax rat bladder was not correlated with the degree of tone. Isoprenaline was significantly less potent and effective in causing relaxation against carbachol-induced tone than against any other stimulus, whereas no such relationship was observed for forskolin. CONCLUSIONS We conclude that β-adrenoceptor agonists can induce rat bladder relaxation against a wide range of contractile stimuli and are more potent and/or effective against non-cholinergic stimuli than against muscarinic agonism. This profile appears desirable for agents intended for the treatment of overactive bladder.
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Abstract
Within the urinary tract, β-adrenergic receptors (AR) are found largely on smooth muscle cells but are also present, at least in the bladder, in the urothelium and on afferent nerves. Our understanding of β-AR subtype expression and function is hampered by a lack of well-validated tools, particularly with regard to β(3)-AR. Moreover, the β-AR subtypes involved in a specific function may differ between species. In the ureter, β-AR can modulate pacemaker activity and smooth muscle tone involving multiple subtypes. In the human bladder, β-AR promote urine storage. Bladder smooth muscle relaxation primarily involves β(3)-AR, and the agonists selective for this subtype are in clinical development to treat bladder dysfunction. While prostate and urethra also express β-AR, the overall physiological role in these tissues remains unclear.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, Meibergdreef 15, 1105 AZ, Amsterdam, The Netherlands.
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Michel MC, Ochodnicky P, Summers RJ. Tissue functions mediated by beta(3)-adrenoceptors-findings and challenges. Naunyn Schmiedebergs Arch Pharmacol 2010; 382:103-8. [PMID: 20517594 PMCID: PMC2904903 DOI: 10.1007/s00210-010-0529-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 05/18/2010] [Indexed: 11/26/2022]
Abstract
As β3-adrenoceptor agonists metamorphose from experimental tools into therapeutic drugs, it is vital to obtain a comprehensive picture of the cell and tissue functions mediated by this receptor subtype in humans. Human tissues with proven functions and/or a high expression of β3-adrenoceptors include the urinary bladder, the gall bladder, and other parts of the gastrointestinal tract. While several other β3-adrenoceptor functions have been proposed based on results obtained in animals, their relevance to humans remains uncertain. For instance, β3-adrenoceptors perform an important role in thermogenesis and lipolysis in rodent brown and white adipose tissue, respectively, but their role in humans appears less significant. Moreover, the use of tools such as the agonist BRL 37344 and the antagonist SR59230A to demonstrate functional involvement of β3-adrenoceptors may lead in many cases to misleading conclusions as they can also interact with other β-adrenoceptor subtypes or even non-adrenoceptor targets. In conclusion, we propose that many responses attributed to β3-adrenoceptor stimulation may need re-evaluation in the light of the development of more selective tools. Moreover, findings in experimental animals need to be extended to humans in order to better understand the potential additional indications and side effects of the β3-adrenoceptor agonists that are beginning to enter clinical medicine.
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Affiliation(s)
- Martin C. Michel
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, Netherlands
| | - Peter Ochodnicky
- Department of Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, Netherlands
| | - Roger J. Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, 3052 Australia
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Chen W, Shi C, Yi S, Chen B, Zhang W, Fang Z, Wei Z, Jiang S, Sun X, Hou X, Xiao Z, Ye G, Dai J. Bladder regeneration by collagen scaffolds with collagen binding human basic fibroblast growth factor. J Urol 2010; 183:2432-9. [PMID: 20403614 DOI: 10.1016/j.juro.2010.02.042] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Indexed: 11/17/2022]
Abstract
PURPOSE Studies show that basic fibroblast growth factor can promote bladder regeneration. However, the lack of targeting delivery approaches limits its clinical application. We investigated a collagen based targeting system for bladder regeneration. A collagen binding domain was added to the native basic fibroblast growth factor N-terminal to allow it to bind to collagen. MATERIALS AND METHODS Sprague-Dawley rats underwent partial cystectomy. Collagen scaffolds loaded with collagen binding domain basic fibroblast growth factor, native basic fibroblast growth factor or phosphate buffered saline were grafted to the remaining host bladders, respectively. At days 30 and 90 reconstructed bladders were evaluated by histological analysis and urodynamics. RESULTS This targeting basic fibroblast growth factor delivery system induced satisfying bladder histological structures. It promoted more vascularization and smooth muscle cell ingrowth. Urodynamics revealed well accommodated bladder tissue with volume capacity and compliance. CONCLUSIONS Results show that the targeting delivery system consisting of collagen binding domain basic fibroblast growth factor and collagen membranes induced better bladder regeneration at the injury site. Thus, this targeting delivery system may be an effective strategy for bladder regeneration with potential clinical applications.
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Affiliation(s)
- Wei Chen
- Department of Urology, Center of Nephrology, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
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Michel MC, Wieland T, Tsujimoto G. How reliable are G-protein-coupled receptor antibodies? Naunyn Schmiedebergs Arch Pharmacol 2009; 379:385-8. [PMID: 19172248 DOI: 10.1007/s00210-009-0395-y] [Citation(s) in RCA: 239] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 01/07/2009] [Indexed: 11/29/2022]
Abstract
A cluster of manuscripts in this issue of the Journal highlights a lack of selectivity of 49 antibodies against 19 subtypes of alpha(1)- and beta-adrenoceptors, muscarinic, dopamine and galanin receptors as well as vanilloid (TRPV1) receptors. Taken together these data demonstrate that lack of selectivity appears to be the rule rather than the exception for antibodies against G-protein-coupled and perhaps also other receptors. Thus, the previously often applied validation of such antibodies by the disappearance of staining in the presence of blocking peptide, i.e. the antigen against which the antibody was raised, alone is insufficient to demonstrate specificity. We propose that receptor antibodies should be validated by at least one of the following techniques: a) disappearance of staining in knock-out animals of the target receptor, b) reduction of staining upon knock-down approaches such as siRNA treatment, c) selectivity of staining in immunoblots or immunocytochemistry for the target receptor vs. related subtypes when expressed in the same cell line and/or d) antibodies raised against multiple distinct epitopes of a receptor yielding very similar staining patterns. Other issues of consideration to obtain reliable results based on receptor antibodies in applications such as immunohistochemistry or immunoblotting are also being discussed.
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Rosskopf D, Michel MC. Pharmacogenomics of G Protein-Coupled Receptor Ligands in Cardiovascular Medicine. Pharmacol Rev 2008; 60:513-35. [DOI: 10.1124/pr.108.000612] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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