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Kwon J, Kim DY, Cho KJ, Hashimoto M, Matsuoka K, Kamijo T, Wang Z, Karnup S, Robertson AM, Tyagi P, Yoshimura N. Pathophysiology of Overactive Bladder and Pharmacologic Treatments Including β3-Adrenoceptor Agonists -Basic Research Perspectives. Int Neurourol J 2024; 28:12-33. [PMID: 38461853 DOI: 10.5213/inj.2448002.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 01/10/2024] [Indexed: 03/12/2024] Open
Abstract
Overactive bladder (OAB) is a symptom-based syndrome defined by urinary urgency, frequency, and nocturia with or without urge incontinence. The causative pathology is diverse; including bladder outlet obstruction (BOO), bladder ischemia, aging, metabolic syndrome, psychological stress, affective disorder, urinary microbiome, localized and systemic inflammatory responses, etc. Several hypotheses have been suggested as mechanisms of OAB generation; among them, neurogenic, myogenic, and urothelial mechanisms are well-known hypotheses. Also, a series of local signals called autonomous myogenic contraction, micromotion, or afferent noises, which can occur during bladder filling, may be induced by the leak of acetylcholine (ACh) or urothelial release of adenosine triphosphate (ATP). They can be transmitted to the central nervous system through afferent fibers to trigger coordinated urgency-related detrusor contractions. Antimuscarinics, commonly known to induce smooth muscle relaxation by competitive blockage of muscarinic receptors in the parasympathetic postganglionic nerve, have a minimal effect on detrusor contraction within therapeutic doses. In fact, they have a predominant role in preventing signals in the afferent nerve transmission process. β3-adrenergic receptor (AR) agonists inhibit afferent signals by predominant inhibition of mechanosensitive Aδ-fibers in the normal bladder. However, in pathologic conditions such as spinal cord injury, it seems to inhibit capsaicin-sensitive C-fibers. Particularly, mirabegron, a β3-agonist, prevents ACh release in the BOO-induced detrusor overactivity model by parasympathetic prejunctional mechanisms. A recent study also revealed that vibegron may have 2 mechanisms of action: inhibition of ACh from cholinergic efferent nerves in the detrusor and afferent inhibition via urothelial β3-AR.
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Affiliation(s)
- Joonbeom Kwon
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Leaders Urology Clinic, Daegu, Korea
| | - Duk Yoon Kim
- Department of Urology, Catholic University of Daegu School of Medicine, Daegu, Korea
| | - Kang Jun Cho
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Mamoru Hashimoto
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kanako Matsuoka
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Tadanobu Kamijo
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Zhou Wang
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sergei Karnup
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anne M Robertson
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh School of Bioengineering, Pittsburgh, PA, USA
| | - Pradeep Tyagi
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Dal Monte M, Evans BA, Arioglu-Inan E, Michel MC. Upregulation of β 3-adrenoceptors-a general marker of and protective mechanism against hypoxia? Naunyn Schmiedebergs Arch Pharmacol 2019; 393:141-146. [PMID: 31853614 DOI: 10.1007/s00210-019-01780-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 11/22/2019] [Indexed: 12/17/2022]
Abstract
β3-Adrenoceptors exhibit a restricted expression pattern, particularly in humans. However, they have been found to be upregulated in various cancers and under several conditions associated with hypoperfusion such as congestive heart failure and diabetes for instance in the heart and other tissues. These conditions are frequently associated with hypoxia. Furthermore, direct induction of hypoxia has consistently been reported to cause upregulation of β3-adrenoceptors across various tissues of multiple species including humans, rats, dogs, and fish. While a canonical hypoxia-response element in the promoter of the human β3-adrenoceptor gene may play a role in this, no such sequence was found in rodent homologs. Moreover, not all upregulation of β3-adrenoceptor protein is accompanied by increased expression of corresponding mRNA, indicating that the upregulation may involve factors other than transcriptional changes. We propose that upregulation of β3-adrenoceptors at the mRNA and/or protein level is a general marker of hypoxic conditions. Moreover, it may be an additional pathway whereby cells and tissues adapt to reduced oxygen levels.
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Affiliation(s)
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Ebru Arioglu-Inan
- 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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Igawa Y, Aizawa N, Michel MC. β 3 -Adrenoceptors in the normal and diseased urinary bladder-What are the open questions? Br J Pharmacol 2019; 176:2525-2538. [PMID: 30868554 DOI: 10.1111/bph.14658] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/31/2018] [Accepted: 01/29/2019] [Indexed: 12/13/2022] Open
Abstract
β3 -Adrenoceptor agonists are used in the treatment of overactive bladder syndrome. Although the relaxant response to adrenergic stimulation in human detrusor smooth muscle cells is mediated mainly via β3 -adrenoceptors, the plasma concentrations of the therapeutic dose of mirabegron, the only clinically approved β3 -adrenoceptor agonist, are considerably lower than the EC50 for causing direct relaxation of human detrusor, suggesting a mechanism of action other than direct relaxation of detrusor smooth muscle. However, the site and mechanism of action of β3 -adrenoceptor agonists in the bladder have not been firmly established. Postulated mechanisms include prejunctional suppression of ACh release from the parasympathetic nerves during the storage phase and inhibition of micro-contractions through β3 -adrenoceptors on detrusor smooth muscle cells or suburothelial interstitial cells. Implications of possible desensitization of β3 -adrenoceptors in the bladder upon prolonged agonist exposure and possible causes of rarely observed cardiovascular effects of mirabegron are also discussed. 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)
- Yasuhiko Igawa
- Department of Continence Medicine, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Naoki Aizawa
- Department of Continence Medicine, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
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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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Michel MC, Chess-Williams R, Hegde SS. Are blood vessels a target to treat lower urinary tract dysfunction? Naunyn Schmiedebergs Arch Pharmacol 2015; 388:687-94. [PMID: 26026700 DOI: 10.1007/s00210-015-1137-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 05/21/2015] [Indexed: 01/12/2023]
Abstract
Bladder dysfunction is common in the general population (Stewart et al. 2010) and even more so among patients seeing a physician for any reason (Goepel et al. 2002). It often manifests as lower urinary tract symptoms (LUTS), a term originally coined to describe voiding and storage symptoms in men with benign prostatic hyperplasia (BPH) but now more universally used to describe any type of voiding and storage symptoms in both sexes. Studies into possible causes of urinary bladder dysfunction have long focused on detrusor smooth muscle cells (Turner and Brading 1999). More recently, it became clear that several other types of cells and organs contribute to regulating detrusor smooth muscle function. These include the urothelium (Andersson and McCloskey 2014; Michel 2015), afferent nerves (Michel and Igawa 2015; Yoshimura et al. 2014b), and the central and autonomic nervous systems (Fowler and Griffiths 2010; Yoshimura et al. 2014a). Alterations in any of these may at least partly be responsible for detrusor dysfunction and, accordingly, be potential targets for the treatment of bladder dysfunction. As highlighted by an article in this issue of Naunyn-Schmiedeberg's Archives of Pharmacology (Bayrak et al. 2015), there is an additional suspect, the bladder vasculature. This article will discuss the currently available experimental and clinical evidence for a role of the vasculature in causing bladder dysfunction, and how existing and emerging treatments may modulate bladder function by acting on blood vessels. Due to a similarity in concept, data on prostate perfusion will also be discussed to some extent.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg Universität, Obere Zahlbacher Str. 67, 55101, Mainz, Germany,
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