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Barut EN, Engin S, Dağlar G, Erac Y, Sari S, Kadioglu M. Ranolazine attenuates mouse detrusor contractility: Evidence for the involvement of calcium-related mechanisms. Eur J Pharmacol 2025; 993:177377. [PMID: 39952583 DOI: 10.1016/j.ejphar.2025.177377] [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: 10/17/2024] [Revised: 01/15/2025] [Accepted: 02/11/2025] [Indexed: 02/17/2025]
Abstract
Ranolazine (RNZ) is a multifaceted ion channel modulator approved for the treatment of angina. Although various pleiotropic effects on the cardiovascular system have been demonstrated, its efficacy in the urinary system remains not fully understood. Here, we aimed to investigate the effect of RNZ on mouse detrusor smooth muscle (DSM) contractility and the mechanism(s) of its action by using isolated tissue bath technique. RNZ significantly decreased carbachol (CCh)-, KCl- and electrical field stimulation-induced contractility and induced relaxation in DSM concentration-dependently. Furthermore, RNZ-induced relaxation of KCl-precontracted DSM strips was not altered in the presence of 4-aminopyridine, BaCl2, glibenclamide, TEA, propranolol, L-NAME or methylene blue, indicating that K+ channels, nitric oxide/cGMP pathway or β-adrenoreceptors are not involved in the relaxant effect of RNZ. Also, RNZ significantly inhibited the contractile response induced by CaCl2, CCh, and Bay K8644 under Ca++-free conditions. Regarding the molecular docking and cytosolic Ca++ mobilization assays, RNZ showed affinity for the antagonist binding site of L-type Ca++ channels and significantly decreased cytosolic Ca++ level in A7r5 cells. These findings suggest the inhibition of Ca++ influx and release may contribute to RNZ-induced DSM relaxation. Hence, our results provide strong evidence that RNZ has a notable relaxant effect on mouse DSM by inhibiting Ca++ influx and release of Ca++ from intracellular stores and it has the potential to be a therapeutic candidate for LUTS.
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Affiliation(s)
- Elif Nur Barut
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye.
| | - Seçkin Engin
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye
| | - Gökçe Dağlar
- Ege University, Faculty of Pharmacy, Department of Pharmacology, İzmir, Türkiye
| | - Yasemin Erac
- Ege University, Faculty of Pharmacy, Department of Pharmacology, İzmir, Türkiye
| | - Suat Sari
- Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Ankara, Türkiye
| | - Mine Kadioglu
- Karadeniz Technical University, Faculty of Medicine, Department of Medical Pharmacology, Trabzon, Türkiye
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Gibson S, Ellsworth P. Emerging therapies for overactive bladder: preclinical, phase I and phase II studies. Expert Opin Investig Drugs 2024; 33:601-612. [PMID: 38695250 DOI: 10.1080/13543784.2024.2349285] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/25/2024] [Indexed: 06/25/2024]
Abstract
INTRODUCTION Overactive bladder syndrome is a common chronic condition with a significant impact on quality of life and economic burden. Persistence with pharmacologic therapy has been limited by efficacy and side effects. A greater understanding of the pathophysiology of overactive bladder has led to the initial evaluation of several drugs affecting ion channels, the autonomic nervous system, and enzymes which may provide useful alternatives for the management of overactive bladder. AREAS COVERED A comprehensive review was performed using PubMed and Cochrane databases as well as reviewing clinical trials in the United States. The current standard of care for overactive bladder will be discussed, but this paper focuses on investigational drugs currently in preclinical studies and phase I and II clinical trials. EXPERT OPINION Current therapies for overactive bladder have limitations in efficacy and side effects. A greater understanding of the pathophysiology of overactive bladder has identified the role(s) of other pathways in the overactive bladder syndrome. Targeting alternative pathways including ion channels and enzymes may provide alternative therapies of overactive bladder and a more tailored approach to the management of overactive bladder.
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Affiliation(s)
- Samantha Gibson
- Division of urology, University of Central Florida College of Medicine, Orlando, FL, USA
| | - Pamela Ellsworth
- Division of urology, University of Central Florida College of Medicine, Orlando, FL, USA
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3
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D’Agostino G, Salvatore S, Calvi P, Condino AM. Inhibition of prejunctional parasympathetic pathways by β 3-adrenoceptor agonists in the isolated pig detrusor: comparison with human detrusor studies. Front Pharmacol 2023; 14:1177653. [PMID: 37234719 PMCID: PMC10206075 DOI: 10.3389/fphar.2023.1177653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Adrenergic receptors of the β3-subtype (β3-ADRs) seem to represent a new target for a more effective pharmacological treatment of overactive bladder (OAB), a wide spread urinary disorder. A promising opportunity for OAB therapy might rely on the development of selective β3-ADR agonists, but an appropriate preclinical screening, as well as investigation of their pharmacological mechanism(s), is limited by poor availability of human bladder samples and of translational animal models. In this study, we used the porcine urinary bladder as experimental tool to ascertain the functions of β3-ADRs in the control the parasympathetic motor drive. Tritiated acetylcholine ([3H]-ACh), mainly originated from neural stores, was released by electrical field stimulation (EFS) in epithelium-deprived detrusor strips from pigs bred without estrogens. EFS produced simultaneously [3H]-ACh release and smooth muscle contraction allowing to asses neural (pre-junctional) and myogenic (postjunctional) effects in the same experiment. Isoprenaline and mirabegron produced on the EFS-evoked effects a concentration-dependent inhibition antagonized by L-748,337, a high selective β3-ADR antagonist. The analysis of the resultant pharmacodynamic parameters supports the notion that in pig detrusors, as well as in previously described human detrusors, the activation of inhibitory β3-ADRs can modulate neural parasympathetic pathways. In such inhibitory control, the involvement of membrane K+ channels, mainly of the SK type, seems to play a pivotal role similarly to what previously described in humans. Therefore, the isolated porcine detrusor can provide a suitable experimental tool to study the mechanisms underlying the clinical efficacy of selective β3-ADR compounds for human use.
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Affiliation(s)
| | - Stefano Salvatore
- Department of Obstetrics and Gynaecology, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Calvi
- Cellini Clinic, Humanitas Group, Torino, Italy
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Li J, Liu T, Li N, Dong F, Wang P. SKA-31-induced activation of small-conductance calcium-activated potassium channels decreased modulation of detrusor smooth muscle function in a rat model of obesity. J Bioenerg Biomembr 2022; 54:135-144. [PMID: 35478071 DOI: 10.1007/s10863-022-09939-2] [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: 12/03/2021] [Accepted: 04/15/2022] [Indexed: 10/18/2022]
Abstract
Increased excitability and contractility of detrusor smooth muscle (DSM) cells are associated with overactive bladder (OAB), which is often induced by obesity. Small-conductance Ca2+-activated K+ (SK) channels regulate the excitability and contractility of DSM cells. Selective pharmacological activation of SK channels attenuates hyperpolarization and the decreased relaxation effect in DSM cells in obesity-induced OAB. However, additional data are needed to confirm the regulatory effect of SK channels on the function of DSM cells in obesity-related OAB. The tested hypothesis was that activation of SK channels decreases modulation of DSM function in a rat model of obesity-related OAB. Female Sprague Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD), weighed after 12 weeks, and subjected to urodynamic study, patch-clamp electrophysiology, and isometric tension recording. The average body weight and incidence of OAB were increased in the HFD group. Patch-clamp studies revealed that pharmacological activation of SK channels with SKA-31 had attenuated hyperpolarization of DSM cells. In addition, isometric tension recordings indicated that SKA-31 decreased relaxation of spontaneous phasic contractions of DSM strips in the HFD group. Attenuated function of SK channels increased the excitability and contractility of DSM cells, which contributed to the occurrence of OAB, suggesting that SK channels are potential therapeutic targets for control of OAB.
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Affiliation(s)
- Jingyu Li
- Department of Urology, The Fourth Affiliated Hospital of China Medical University, Chongshan East Rd, Huanggu District, No. 4, Shenyang, Liaoning, 110032, China
| | - Tiandong Liu
- Department of Urology, Dandong Central Hospital, Dandong, Liaoning, China
| | - Ning Li
- Department of Urology, The Fourth Affiliated Hospital of China Medical University, Chongshan East Rd, Huanggu District, No. 4, Shenyang, Liaoning, 110032, China
| | - Fengming Dong
- Department of Urology, The Fourth Affiliated Hospital of China Medical University, Chongshan East Rd, Huanggu District, No. 4, Shenyang, Liaoning, 110032, China
| | - Ping Wang
- Department of Urology, The Fourth Affiliated Hospital of China Medical University, Chongshan East Rd, Huanggu District, No. 4, Shenyang, Liaoning, 110032, China.
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Joseph S, Maria SA, Peedicayil J. Drugs Currently Undergoing Preclinical or Clinical Trials for the Treatment of Overactive Bladder: A Review. Curr Ther Res Clin Exp 2022; 96:100669. [PMID: 35494662 PMCID: PMC9052038 DOI: 10.1016/j.curtheres.2022.100669] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/25/2022] [Indexed: 11/29/2022] Open
Abstract
Background Overactive bladder (OAB) is a common clinical condition for which current drug treatment comprises drugs blocking the cholinergic nerve supply, or augmenting the adrenergic nerve supply, to the detrusor muscle of the urinary bladder. Current treatments have drawbacks, including lack of efficacy and the development of adverse effects in some patients. Hence, new and better drugs for treating OAB will be clinically useful. Objective This review is meant to provide information on drugs currently undergoing preclinical or clinical trials for the treatment of OAB published in journal articles or elsewhere. Methods The cited articles were retrieved from PubMed and Google Scholar from January 1, 1990, to December 31, 2021. The search terms used were contraction or contractility, detrusor, inhibition, isolated or in vitro, in vivo, overactive bladder, and relaxant effect or relaxation. Results There are 4 classes of new drugs under various stages of development for the treatment of OAB. These are drugs acting on the autonomic nerve supply to the detrusor muscle of the urinary bladder that include the anticholinergics tarafenacin and afacifenacin and the β3 adrenoceptor agonists solabegron and ritobegron; drugs acting on ion channels in the detrusor muscle (eg, potassium channel openers and calcium channel blockers), drugs acting on cellular enzymes like phosphodiesterase-5 inhibitors and Rho kinase inhibitors, and drugs acting on miscellaneous targets (eg, pregabalin and trimetazidine). Conclusions Drugs currently used to treat OAB target only the cholinergic and adrenergic cellular signalling pathways. There are many other drugs under trial targeting other cellular pathways that may be useful for treating OAB. Their approval for clinical use might improve the treatment of patients with OAB. (Curr Ther Res Clin Exp. 2022; 83:XXX–XXX)
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Malysz J, Petkov GV. Detrusor Smooth Muscle K V7 Channels: Emerging New Regulators of Urinary Bladder Function. Front Physiol 2020; 11:1004. [PMID: 33041840 PMCID: PMC7526500 DOI: 10.3389/fphys.2020.01004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/23/2020] [Indexed: 01/21/2023] Open
Abstract
Relaxation and contraction of the urinary bladder smooth muscle, also known as the detrusor smooth muscle (DSM), facilitate the micturition cycle. DSM contractility depends on cell excitability, which is established by the synchronized activity of multiple diverse ion channels. K+ channels, the largest family of channels, control DSM excitability by maintaining the resting membrane potential and shaping the action potentials that cause the phasic contractions. Among the members of the voltage-gated K+ (KV) channel superfamily, KV type 7 (KV7) channels - KV7.1-KV7.5 members encoded by KCNQ1-KCNQ5 genes - have been recently identified as functional regulators in various cell types including vascular, cardiac, and neuronal cells. Their regulatory roles in DSM, however, are just now emerging and remain to be elucidated. To address this gap, our research group has initiated the systematic investigation of human DSM KV7 channels in collaboration with clinical urologists. In this comprehensive review, we summarize the current understanding of DSM Kv7 channels and highlight recent discoveries in the field. We describe KV7 channel expression profiles at the mRNA and protein levels, and further elaborate on functional effects of KV7 channel selective modulators on DSM excitability, contractility, and intracellular Ca2+ dynamics in animal species along with in vivo studies and the limited data on human DSM. Within each topic, we highlight the main observations, current gaps in knowledge, and most pressing questions and concepts in need of resolution. We emphasize the lack of systematic studies on human DSM KV7 channels that are now actively ongoing in our laboratory.
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Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Georgi V. Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
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Malysz J, Petkov GV. Urinary bladder smooth muscle ion channels: expression, function, and regulation in health and disease. Am J Physiol Renal Physiol 2020; 319:F257-F283. [PMID: 32628539 PMCID: PMC7473901 DOI: 10.1152/ajprenal.00048.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/21/2020] [Accepted: 06/28/2020] [Indexed: 12/17/2022] Open
Abstract
Urinary bladder smooth muscle (UBSM), also known as detrusor smooth muscle, forms the bladder wall and ultimately determines the two main attributes of the organ: urine storage and voiding. The two functions are facilitated by UBSM relaxation and contraction, respectively, which depend on UBSM excitability shaped by multiple ion channels. In this review, we summarize the current understanding of key ion channels establishing and regulating UBSM excitability and contractility. They include excitation-enhancing voltage-gated Ca2+ (Cav) and transient receptor potential channels, excitation-reducing K+ channels, and still poorly understood Cl- channels. Dynamic interplay among UBSM ion channels determines the overall level of Cav channel activity. The net Ca2+ influx via Cav channels increases global intracellular Ca2+ concentration, which subsequently triggers UBSM contractility. Here, for each ion channel type, we describe UBSM tissue/cell expression (mRNA and protein) profiles and their role in regulating excitability and contractility of UBSM in various animal species, including the mouse, rat, and guinea pig, and, most importantly, humans. The currently available data reveal certain interspecies differences, which complicate the translational value of published animal research results to humans. This review highlights recent developments, findings on genetic knockout models, pharmacological data, reports on UBSM ion channel dysfunction in animal bladder disease models, and the very limited human studies currently available. Among all gaps in present-day knowledge, the unknowns on expression and functional roles for ion channels determined directly in human UBSM tissues and cells under both normal and disease conditions remain key hurdles in the field.
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Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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Fry CH, Chakrabarty B, Hashitani H, Andersson KE, McCloskey K, Jabr RI, Drake MJ. New targets for overactive bladder-ICI-RS 2109. Neurourol Urodyn 2020; 39 Suppl 3:S113-S121. [PMID: 31737931 PMCID: PMC8114459 DOI: 10.1002/nau.24228] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 10/31/2019] [Indexed: 12/16/2022]
Abstract
AIM To review evidence for novel drug targets that can manage overactive bladder (OAB) symptoms. METHODS A think tank considered evidence from the literature and their own research experience to propose new drug targets in the urinary bladder to characterize their use to treat OAB. RESULTS Five classes of agents or cellular pathways were considered. (a) Cyclic nucleotide-dependent (cyclic adenosine monophosphate and cyclic guanosine monophosphate) pathways that modulate adenosine triphosphate release from motor nerves and urothelium. (b) Novel targets for β3 agonists, including the bladder wall vasculature and muscularis mucosa. (c) Several TRP channels (TRPV1 , TRPV4 , TRPA1 , and TRPM4 ) and their modulators in affecting detrusor overactivity. (d) Small conductance Ca2+ -activated K+ channels and their influence on spontaneous contractions. (e) Antifibrosis agents that act to modulate directly or indirectly the TGF-β pathway-the canonical fibrosis pathway. CONCLUSIONS The specificity of action remains a consideration if particular classes of agents can be considered for future development as receptors or pathways that mediate actions of the above mentioned potential agents are distributed among most organ systems. The tasks are to determine more detail of the pathological changes that occur in the OAB and how the specificity of potential drugs may be directed to bladder pathological changes. An important conclusion was that the storage, not the voiding, phase in the micturition cycle should be investigated and potential targets lie in the whole range of tissue in the bladder wall and not just detrusor.
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Affiliation(s)
- Christopher Henry Fry
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Basu Chakrabarty
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University, Nagoya, Japan
| | - Karl-Erik Andersson
- Institute of Laboratory Medicine, Lund University, Lund, Sweden
- Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Karen McCloskey
- School of Medicine, Dentistry and Biomedical Sciences, Queens University Belfast, Belfast, UK
| | - Rita I. Jabr
- Division of Biochemical Sciences, Faculty of Health and Biomedical Sciences, University of Surrey, Guildford, UK
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Attenuated regulatory function of the small-conductance Ca 2+-activated K + channel in detrusor smooth muscle cells excitability in an obese rat model. Int Urol Nephrol 2020; 52:1851-1861. [PMID: 32399771 DOI: 10.1007/s11255-020-02487-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/29/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE Overactive bladder (OAB) is related to detrusor overactivity (DO), which is caused by the increased detrusor smooth muscle (DSM) cells excitability. Small-conductance Ca2+-activated K+ (SK) channels is a fundamental regulator of excitability and contractility in DSM cells. Obesity-related OAB is associated with the decreased expression and regulatory function of SK channels in DSM layer. However, the regulation role of SK channels in obesity-related OAB DSM cell excitability is still unknown. Here, we tested the hypothesis that obesity-related OAB is associated with reduced expression and activity of SK channels in DSM cells. METHODS Female Sprague-Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD) and weighed after 12 weeks. We performed urodynamic study, single-cell quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and patch-clamp electrophysiology. RESULTS Increased average body weights and urodynamically demonstrated OAB were observed in HFD rats. Single-cell qRT-PCR experiments discovered the decreased mRNA expression level of SK channel in DSM cell from HFD rats. Patch-clamp studies revealed that NS309, a SK channel activator, had an attenuated effect on membrane potential hyperpolarization in HFD DSM cells. In addition, the reduced whole cell SK channel currents were recorded in HFD DSM cells. CONCLUSIONS Attenuated SK channels expression and function, which results in the increased DSM cells excitability and contributes to DO, is discovered in obesity-related OAB DSM cells, suggesting that SK channels might be potential therapeutic targets to control OAB.
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10
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Li N, Ding H, Li Z, Liu Y, Wang P. Effect of high-fat diet-induced obesity on the small-conductance Ca 2+-activated K + channel function affecting the contractility of rat detrusor smooth muscle. Int Urol Nephrol 2018; 51:61-72. [PMID: 30361965 DOI: 10.1007/s11255-018-2016-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/19/2018] [Indexed: 12/01/2022]
Abstract
PURPOSE Obesity usually induces overactive bladder (OAB) associated with detrusor overactivity, which is related to increased contractility of the detrusor smooth muscle (DSM). Small-conductance Ca2+-activated K+ (SK) channels play a constitutive role in the regulation of DSM contractility. However, the role of SK channels in the DSM changes in obesity-related OAB is still unknown. Here, we tested the hypothesis that obesity-related OAB is associated with reduced expression and activity of SK channels in DSM and that SK channels activation is a potential treatment for OAB. METHODS Female Sprague-Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD) and weighed after 12 weeks. Urodynamic studies, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and isometric tension recording were performed. RESULTS Increased average body weights and urodynamically demonstrated OAB were observed in HFD rats. qRT-PCR experiments revealed a decrease in the mRNA expression level of SK channel in DSM tissue of the HFD rats. Isometric tension recordings indicated an attenuated relaxation effect of NS309 on the spontaneous phasic and electrical field stimulation-induced contractions that occurred via SK channel activation in HFD DSM strips. CONCLUSIONS Reduced expression and activity of SK channels in the DSM contribute to obesity-related OAB, indicating that SK channels are a potential therapeutic target for OAB.
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Affiliation(s)
- Ning Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Honglin Ding
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.,Department of Urology, Affiliated Hospital, Chifeng University, 42 Wangfu Street, Chifeng, Neimeng, China
| | - Zizheng Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Yili Liu
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.
| | - Ping Wang
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
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Mahapatra C, Brain KL, Manchanda R. A biophysically constrained computational model of the action potential of mouse urinary bladder smooth muscle. PLoS One 2018; 13:e0200712. [PMID: 30048468 PMCID: PMC6061979 DOI: 10.1371/journal.pone.0200712] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 07/02/2018] [Indexed: 11/19/2022] Open
Abstract
Urinary incontinence is associated with enhanced spontaneous phasic contractions of the detrusor smooth muscle (DSM). Although a complete understanding of the etiology of these spontaneous contractions is not yet established, it is suggested that the spontaneously evoked action potentials (sAPs) in DSM cells initiate and modulate the contractions. In order to further our understanding of the ionic mechanisms underlying sAP generation, we present here a biophysically detailed computational model of a single DSM cell. First, we constructed mathematical models for nine ion channels found in DSM cells based on published experimental data: two voltage gated Ca2+ ion channels, an hyperpolarization-activated ion channel, two voltage-gated K+ ion channels, three Ca2+-activated K+ ion channels and a non-specific background leak ion channel. The ion channels' kinetics were characterized in terms of maximal conductances and differential equations based on voltage or calcium-dependent activation and inactivation. All ion channel models were validated by comparing the simulated currents and current-voltage relations with those reported in experimental work. Incorporating these channels, our DSM model is capable of reproducing experimentally recorded spike-type sAPs of varying configurations, ranging from sAPs displaying after-hyperpolarizations to sAPs displaying after-depolarizations. The contributions of the principal ion channels to spike generation and configuration were also investigated as a means of mimicking the effects of selected pharmacological agents on DSM cell excitability. Additionally, the features of propagation of an AP along a length of electrically continuous smooth muscle tissue were investigated. To date, a biophysically detailed computational model does not exist for DSM cells. Our model, constrained heavily by physiological data, provides a powerful tool to investigate the ionic mechanisms underlying the genesis of DSM electrical activity, which can further shed light on certain aspects of urinary bladder function and dysfunction.
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Affiliation(s)
- Chitaranjan Mahapatra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Keith L. Brain
- School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, England, United Kingdom
| | - Rohit Manchanda
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
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12
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Mathew John C, Khaddaj Mallat R, George G, Kim T, Mishra RC, Braun AP. Pharmacologic targeting of endothelial Ca 2+-activated K + channels: A strategy to improve cardiovascular function. Channels (Austin) 2018; 12:126-136. [PMID: 29577810 PMCID: PMC5972810 DOI: 10.1080/19336950.2018.1454814] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 03/15/2018] [Indexed: 12/17/2022] Open
Abstract
Endothelial small and intermediate-conductance, Ca2+-activated K+ channels (KCa2.3 and KCa3.1, respectively) play an important role in the regulation of vascular function and systemic blood pressure. Growing evidence indicates that they are intimately involved in agonist-evoked vasodilation of small resistance arteries throughout the circulation. Small molecule activators of KCa2.x and 3.1 channels, such as SKA-31, can acutely inhibit myogenic tone in isolated resistance arteries, induce effective vasodilation in intact vascular beds, such as the coronary circulation, and acutely decrease systemic blood pressure in vivo. The blood pressure-lowering effect of SKA-31, and early indications of improvement in endothelial dysfunction suggest that endothelial KCa channel activators could eventually be developed into a new class of endothelial targeted agents to combat hypertension or atherosclerosis. This review summarises recent insights into the activation of endothelial Ca2+ activated K+ channels in various vascular beds, and how tools, such as SKA-31, may be beneficial in disease-related conditions.
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Affiliation(s)
- Cini Mathew John
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Rayan Khaddaj Mallat
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Grace George
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Taeyeob Kim
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ramesh C. Mishra
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Andrew P. Braun
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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13
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Lee K, Isogai A, Antoh M, Kajioka S, Eto M, Hashitani H. Role of K + channels in regulating spontaneous activity in the muscularis mucosae of guinea pig bladder. Eur J Pharmacol 2017; 818:30-37. [PMID: 29050967 DOI: 10.1016/j.ejphar.2017.10.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/30/2022]
Abstract
To explore the roles of various K+ channels in regulating the spontaneous activity of bladder muscularis mucosae (MM) that is considered to play an important role in maintaining mucosal function. Effects of K+ channel modulators on electrical and contractile activity in the guinea-pig bladder MM were examined using intracellular microelectrode and isometric tension recording. The MM predominately generated bursting spontaneous action potentials (SAPs) and phasic contractions (SPCs) that were blocked by nifedipine (1µM). NS309 (10µM), a small-conductance Ca2+-activated K+ (SK) channel opener, dramatically prolonged after-hyperpolarisation (AHP) and converted bursting SAPs into individually action potentials in an apamin (100nM)-sensitive manner. Apamin alone increased the number of SAPs during bursts. NS1619 (10µM), a large-conductance Ca2+-activated K+ (BK) channel opener, abolished SAPs in a manner reversed by iberiotoxin (IbTX, 100nM), a BK channel blocker. IbTX alone enlarged SAPs and abolished their AHPs. Flupirtine (10µM), a voltage-dependent K+ channel (Kv7) opener, diminished SAPs in a manner reversed by XE991 (10µM), a Kv7 channel blocker. XE991 alone exerted modest excitatory effects on SAPs. These K+ channel modulators had corresponding effects on SPCs. Bursting SAP firing appears to result from a lower level activation of SK channels in MM than that DSM. BK channels play a predominant role in regulating SAP configuration, while Kv7 channels have only a marginal role. The prevention of bursting SAPs and associated reduction in SPCs upon the pharmacological activation of a reserved population of SK channels may well have a considerable therapeutic potential.
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Affiliation(s)
- Ken Lee
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan; Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Ayu Isogai
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Minori Antoh
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Shunichi Kajioka
- Department of Applied Urology and Molecular Medicine, Kyushu University, Fukuoka, Japan
| | - Masatoshi Eto
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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Chen KH, Liu H, Sun HY, Jin MW, Xiao GS, Wang Y, Li GR. The Natural Flavone Acacetin Blocks Small Conductance Ca 2+-Activated K + Channels Stably Expressed in HEK 293 Cells. Front Pharmacol 2017; 8:716. [PMID: 29081746 PMCID: PMC5646423 DOI: 10.3389/fphar.2017.00716] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Accepted: 09/25/2017] [Indexed: 01/06/2023] Open
Abstract
The natural flavone acacetin inhibits several voltage-gated potassium currents in atrial myocytes, and has anti-atrial fibrillation (AF) effect in experimental AF models. The present study investigates whether acacetin inhibits the Ca2+-activated potassium (KCa) currents, including small conductance (SKCa1, SKCa2, and SKCa3), intermediate conductance (IKCa), and large-conductance (BKCa) channels stably expressed in HEK 293 cells. The effects of acacetin on these KCa channels were determined with a whole-cell patch voltage-clamp technique. The results showed that acacetin inhibited the three subtype SKCa channel currents in concentration-dependent manner with IC50 of 12.4 μM for SKCa1, 10.8 μM for SKCa2, and 11.6 μM for SKCa3. Site-directed mutagenesis of SKCa3 channels generated the mutants H490N, S512T, H521N, and A537V. Acacetin inhibited the mutants with IC50 of 118.5 μM for H490N, 275.2 μM for S512T, 15.3 μM for H521N, and 10.6 μM for A537V, suggesting that acacetin interacts with the P-loop helix of SKCa3 channel. However, acacetin at 3–10 μM did not decrease, but induced a slight increase of BKCa (+70 mV) by 8% at 30 μM. These results demonstrate the novel information that acacetin remarkably inhibits SKCa channels, but not IKCa or BKCa channels, which suggests that blockade of SKCa by acacetin likely contributes to its anti-AF property previously observed in experimental AF.
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Affiliation(s)
- Kui-Hao Chen
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong.,Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Liu
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong.,Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hai-Ying Sun
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong
| | - Man-Wen Jin
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guo-Sheng Xiao
- Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
| | - Gui-Rong Li
- Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong.,Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, China
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Li N, Ding H, He X, Li Z, Liu Y. Expression and function of the small-conductance Ca 2+-activated K + channel is decreased in urinary bladder smooth muscle cells from female guinea pig with partial bladder outlet obstruction. Int Urol Nephrol 2017; 49:1147-1155. [PMID: 28417339 DOI: 10.1007/s11255-017-1592-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/10/2017] [Indexed: 01/10/2023]
Abstract
PURPOSE Overactive bladder (OAB), usually accompanied by partial bladder outlet obstruction (PBOO), is associated with detrusor overactivity (DO) which is related to the increased urinary bladder smooth muscle (UBSM) cells excitability. Small-conductance Ca2+-activated K+ (SK) channels play a constitutive regulatory role of UBSM excitability and contractility. PBOO is associated with the decreased SK channels mRNA expression and the attenuated regulative effect of SK channels on UBSM contractility. However, the regulation of SK channels in PBOO UBSM cell excitability is less clear. Here, we tested the hypothesis that PBOO is associated with decreased expression and function of SK channels in UBSM cells and that SK channels are a potential target for the treatment of OAB. METHODS Cystometry indicated that DO was achieved 2 weeks after PBOO in female guinea pigs. Using this animal model, we conducted single-cell quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and patch-clamp electrophysiology. RESULTS The single-cell qRT-PCR experiments indicated the reduced SK channel mRNA expression in PBOO UBSM cells. Patch-clamp studies revealed that NS309 had a diminished effect on resting membrane potential hyperpolarization via the activation of SK channels in PBOO UBSM cells. Moreover, attenuated whole-cell SK channel currents were demonstrated in PBOO UBSM cells. CONCLUSIONS The attenuated expression and function of SK channels, which results in the increased UBSM cells excitability and contributes to DO, was discovered in PBOO UBSM cells, suggesting that SK channels might be potential therapeutic targets for the control of OAB.
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Affiliation(s)
- Ning Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Honglin Ding
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Xiaoning He
- Department of Stomatology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Zizheng Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Yili Liu
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.
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Li N, He X, Li Z, Liu Y, Wang P. Partial bladder outlet obstruction is associated with decreased expression and function of the small-conductance Ca2+-activated K+ channel in guinea pig detrusor smooth muscle. Int Urol Nephrol 2016; 49:17-26. [DOI: 10.1007/s11255-016-1455-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 11/03/2016] [Indexed: 10/24/2022]
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Effects of K(+) channel openers on spontaneous action potentials in detrusor smooth muscle of the guinea-pig urinary bladder. Eur J Pharmacol 2016; 789:179-186. [PMID: 27455901 DOI: 10.1016/j.ejphar.2016.07.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/22/2016] [Accepted: 07/22/2016] [Indexed: 12/18/2022]
Abstract
The modulation of spontaneous excitability in detrusor smooth muscle (DSM) upon the pharmacological activation of different populations of K(+) channels was investigated. Effects of distinct K(+) channel openers on spontaneous action potentials in DSM of the guinea-pig bladder were examined using intracellular microelectrode techniques. NS1619 (10μM), a large conductance Ca(2+)-activated K(+) (BK) channel opener, transiently increased action potential frequency and then prevented their generation without hyperpolarizing the membrane in a manner sensitive to iberiotoxin (IbTX, 100nM). A higher concentration of NS1619 (30μM) hyperpolarized the membrane and abolished action potential firing. NS309 (10μM) and SKA31 (100μM), small conductance Ca(2+)-activated K(+) (SK) channel openers, dramatically increased the duration of the after-hyperpolarization and then abolished action potential firing in an apamin (100nM)-sensitive manner. Flupirtine (10μM), a Kv7 channel opener, inhibited action potential firing without hyperpolarizing the membrane in a manner sensitive to XE991 (10μM), a Kv7 channel blocker. BRL37344 (10μM), a β3-adrenceptor agonist, or rolipram (10nM), a phosphodiesterase 4 inhibitor, also inhibited action potential firing. A higher concentration of rolipram (100nM) hyperpolarized the DSM and abolished the action potentials. IbTX (100nM) prevented the rolipram-induced blockade of action potentials but not the hyperpolarization. BK and Kv7 channels appear to predominantly contribute to the stabilization of DSM excitability. Spare SK channels could be pharmacologically activated to suppress DSM excitability. BK channels appear to be involved in the cyclic AMP-induced inhibition of action potentials but not the membrane hyperpolarization.
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Köhler R, Oliván-Viguera A, Wulff H. Endothelial Small- and Intermediate-Conductance K Channels and Endothelium-Dependent Hyperpolarization as Drug Targets in Cardiovascular Disease. ADVANCES IN PHARMACOLOGY 2016; 77:65-104. [DOI: 10.1016/bs.apha.2016.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Abstract
The mammalian urethra is a muscular tube responsible for ensuring that urine remains in the urinary bladder until urination. In order to prevent involuntary urine leakage, the urethral musculature must be capable of constricting the urethral lumen to an extent that exceeds bladder intravesicular pressure during the urine-filling phase. The main challenge in anti-incontinence treatments involves selectively-controlling the excitability of the smooth muscles in the lower urinary tract. Almost all strategies to battle urinary incontinence involve targeting the bladder and as a result, this tissue has been the focus for the majority of research and development efforts. There is now increasing recognition of the value of targeting the urethral musculature in the treatment and management of urinary incontinence. Newly-identified and characterized ion channels and pathways in the smooth muscle of the urethra provides a range of potential therapeutic targets for the treatment of urinary incontinence. This review provides a summary of the current state of knowledge of the ion channels discovered in urethral smooth muscle cells that regulate their excitability.
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Affiliation(s)
- Barry D Kyle
- a Department of Physiology & Pharmacology; Libin Cardiovascular Institute and The Smooth Muscle Research Group ; University of Calgary ; Calgary , AB Canada
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20
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Sacco E, Recupero S, Bientinesi R, Palermo G, D’Agostino D, Currò D, Bassi P. Pioneering drugs for overactive bladder and detrusor overactivity: Ongoing research and future directions. World J Obstet Gynecol 2015; 4:24-39. [DOI: 10.5317/wjog.v4.i2.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 01/31/2015] [Accepted: 04/14/2015] [Indexed: 02/05/2023] Open
Abstract
The ongoing research on pioneering drug candidates for the overactive bladder (OAB) aimed to overcome the limitations of currently licensed pharmacotherapies, such as antimuscarinics, β3-adrenergic agents, and botulinum neurotoxin, has been reviewed performing a systematic literature review and web search. The review covers the exploratory agents alternative to available medications for OAB and that may ultimately prove to be therapeutically useful in the future management of OAB patients based on preclinical and early clinical data. It emerges that many alternative pharmacological strategies have been discovered or are under investigation in disease-oriented studies. Several potential therapeutics are known for years but still find obstacles to pass the clinical stages of development, while other completely novel compounds, targeting new pharmacological targets, have been recently discovered and show potential to translate into clinical therapeutic agents for idiopathic and neurogenic OAB syndrome. The global scenario of investigational drugs for OAB gives promise for the development of innovative therapeutics that may ultimately prove effective as first, combined or second-line treatments within a realistic timescale of ten years.
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Oliván-Viguera A, Valero MS, Coleman N, Brown BM, Laría C, Murillo MD, Gálvez JA, Díaz-de-Villegas MD, Wulff H, Badorrey R, Köhler R. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo. Mol Pharmacol 2015; 87:338-48. [PMID: 25468883 PMCID: PMC4293453 DOI: 10.1124/mol.114.095745] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/02/2014] [Indexed: 01/09/2023] Open
Abstract
Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic roles of KCa2/3 in the vasculature, central nervous system, and during inflammation in vivo.
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Affiliation(s)
- Aida Oliván-Viguera
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Marta Sofía Valero
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Nicole Coleman
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Brandon M Brown
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Celia Laría
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - María Divina Murillo
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - José A Gálvez
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - María D Díaz-de-Villegas
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Heike Wulff
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Ramón Badorrey
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.)
| | - Ralf Köhler
- Aragon Institute of Health Sciences, Zaragoza, Spain (A.O.-V., R.K.); GIMACES, Facultad de Ciencias de la Salud, Universidad San Jorge, Villanueva de Gállego, Spain (M.S.V., C.L.); Department of Pharmacology, School of Medicine, University of California Davis, Davis, California (N.C., B.M.B, H.W.); Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain (M.D.M.); Departamento de Catálisis y Procesos Catalíticos, Instituto de Síntesis Química y Catálisis Homogénea, Consejo Superior de Investigaciones Científicas-Universidad de Zaragoza, Zaragoza, Spain (M.D.D.-V., J.A.G., R.B.); and Fundación Agencia Aragonesa para la Investigación y Desarrollo (R.K.).
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Sacco E, Bientinesi R. Innovative pharmacotherapies for women with overactive bladder: where are we now and what is in the pipeline? Int Urogynecol J 2014; 26:629-40. [PMID: 25377296 DOI: 10.1007/s00192-014-2557-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/18/2014] [Indexed: 12/12/2022]
Abstract
INTRODUCTION AND HYPOTHESIS The impressive prevalence of overactive bladder (OAB) and the relevant limitations of current treatments urge the need for novel therapeutic approaches. METHODS A systematic literature and web search was performed to identify investigational drugs that entered the early and late phases of clinical development for women with OAB symptoms. RESULTS Approved pharmacological therapies for OAB (antimuscarinics, beta-3 agonists, and botulinum toxin) are evolving with the development of alternative administration methods, combination strategies, and novel compounds, expected to improve effectiveness, bladder selectivity, and dose flexibility. A wealth of investigational compounds, developed with both public and companies' indoor nonclinical disease-oriented studies, entered the early and late stages of clinical development in the last decade. Most non-anticholinergic compounds in ongoing clinical trials target central and peripheral neurotransmitter receptors involved in neurological modulation of micturition, nonadrenergic-noncholinergic mechanisms, cyclic nucleotide metabolism, different subtypes of ion channels or peripheral receptors of prostaglandins, vanilloids, vitamin D3, and opioids. Fascinating advances are ongoing also in the field of genetic therapy. CONCLUSIONS New pharmaceutical formulations and drug combinations are expected to be available in the next decade in order to overcome the limitations of current drugs for OAB. Although proof-of-concept, patient-oriented studies yielded disappointing results for several tentative drugs, a lot of clinical research is ongoing that is expected to provide clinicians with novel therapeutic agents in the near future.
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Affiliation(s)
- Emilio Sacco
- Department of Urology, "Agostino Gemelli" Hospital, Catholic University Medical School, Rome, Italy,
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23
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Ramos-Filho ACS, Shah A, Augusto TM, Barbosa GO, Leiria LO, de Carvalho HF, Antunes E, Grant AD. Menthol inhibits detrusor contractility independently of TRPM8 activation. PLoS One 2014; 9:e111616. [PMID: 25375115 PMCID: PMC4222941 DOI: 10.1371/journal.pone.0111616] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 10/06/2014] [Indexed: 11/19/2022] Open
Abstract
Agonists such as icilin and menthol can activate the cool temperature-sensitive ion channel TRPM8. However, biological responses to menthol may occur independently of TRPM8 activation. In the rodent urinary bladder, menthol facilitates the micturition reflex but inhibits muscarinic contractions of the detrusor smooth muscle. The site(s) of TRPM8 expression in the bladder are controversial. In this study we investigated the regulation of bladder contractility in vitro by menthol. Bladder strips from wild type and TRPM8 knockout male mice (25–30 g) were dissected free and mounted in organ baths. Isometric contractions to carbachol (1 nM–30 µM), CaCl2 (1 µM to 100 mM) and electrical field stimulation (EFS; 8, 16, 32 Hz) were measured. Strips from both groups contracted similarly in response to both carbachol and EFS. Menthol (300 µM) or nifedipine (1 µM) inhibited carbachol and EFS-induced contractions in both wild type and TRPM8 knockout bladder strips. Incubation with the sodium channel blocker tetrodotoxin (1 µM), replacement of extracellular sodium with the impermeant cation N-Methyl-D-Glucamine, incubation with a cocktail of potassium channel inhibitors (100 nM charybdotoxin, 1 µM apamin, 10 µM glibenclamide and 1 µM tetraethylammonium) or removal of the urothelium did not affect the inhibitory actions of menthol. Contraction to CaCl2 was markedly inhibited by either menthol or nifedipine. In cultured bladder smooth muscle cells, menthol or nifedipine abrogated the carbachol or KCl-induced increases in [Ca2+]i. Intravesical administration of menthol increased voiding frequency while decreasing peak voiding pressure. We conclude that menthol inhibits muscarinic bladder contractions through blockade of L-type calcium channels, independently of TRPM8 activation.
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Affiliation(s)
| | - Ajay Shah
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Taize Machado Augusto
- Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Guilherme Oliveira Barbosa
- Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Luiz Osorio Leiria
- Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Hernandes Faustino de Carvalho
- Department of Anatomy, Cellular Biology, Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Edson Antunes
- Department of Pharmacology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Andrew Douglas Grant
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
- * E-mail:
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24
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Petkov GV. Central role of the BK channel in urinary bladder smooth muscle physiology and pathophysiology. Am J Physiol Regul Integr Comp Physiol 2014; 307:R571-84. [PMID: 24990859 DOI: 10.1152/ajpregu.00142.2014] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The physiological functions of the urinary bladder are to store and periodically expel urine. These tasks are facilitated by the contraction and relaxation of the urinary bladder smooth muscle (UBSM), also known as detrusor smooth muscle, which comprises the bladder wall. The large-conductance voltage- and Ca(2+)-activated K(+) (BK, BKCa, MaxiK, Slo1, or KCa1.1) channel is highly expressed in UBSM and is arguably the most important physiologically relevant K(+) channel that regulates UBSM function. Its significance arises from the fact that the BK channel is the only K(+) channel that is activated by increases in both voltage and intracellular Ca(2+). The BK channels control UBSM excitability and contractility by maintaining the resting membrane potential and shaping the repolarization phase of the spontaneous action potentials that determine UBSM spontaneous rhythmic contractility. In UBSM, these channels have complex regulatory mechanisms involving integrated intracellular Ca(2+) signals, protein kinases, phosphodiesterases, and close functional interactions with muscarinic and β-adrenergic receptors. BK channel dysfunction is implicated in some forms of bladder pathologies, such as detrusor overactivity, and related overactive bladder. This review article summarizes the current state of knowledge of the functional role of UBSM BK channels under normal and pathophysiological conditions and provides new insight toward the BK channels as targets for pharmacological or genetic control of UBSM function. Modulation of UBSM BK channels can occur by directly or indirectly targeting their regulatory mechanisms, which has the potential to provide novel therapeutic approaches for bladder dysfunction, such as overactive bladder and detrusor underactivity.
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Affiliation(s)
- Georgi V Petkov
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina
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25
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Stimulation of large-conductance calcium-activated potassium channels inhibits neurogenic contraction of human bladder from patients with urinary symptoms and reverses acetic acid-induced bladder hyperactivity in rats. Eur J Pharmacol 2014; 735:68-76. [PMID: 24747752 DOI: 10.1016/j.ejphar.2014.03.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/10/2014] [Accepted: 03/30/2014] [Indexed: 11/23/2022]
Abstract
We have analysed the effects of large-conductance calcium-activated potassium channel (BK) stimulation on neurogenic and myogenic contraction of human bladder from healthy subjects and patients with urinary symptoms and evaluated the efficacy of activating BK to relief bladder hyperactivity in rats. Bladder specimens were obtained from organ donors and from men with benign prostatic hyperplasia (BPH). Contractions elicited by electrical field stimulation (EFS) and carbachol (CCh) were evaluated in isolated bladder strips. in vivo cystometric recordings were obtained in anesthetized rats under control and acetic acid-induced hyperactive conditions. Neurogenic contractions of human bladder were potentiated by blockade of BK and small-conductance calcium-activated potassium channels (SK) but were unaffected by the blockade of intermediate calcium-activated potassium channels (IK). EFS-induced contractions were inhibited by BK stimulation with NS-8 or NS1619 or by SK/IK stimulation with NS309 (3µM). CCh-induced contractions were not modified by blockade or stimulation of BK, IK or SK. The anti-cholinergic agent, oxybutynin (0.3µM) inhibited either neurogenic or CCh-induced contractions. Neurogenic contractions of bladders from BPH patients were less sensitive to BK inhibition and more sensitive to BK activation than healthy bladders. The BK activator, NS-8 (5mg/kg; i.v.), reversed bladder hyperactivity induced by acetic acid in rats, while oxybutynin was ineffective. NS-8 did not significantly impact blood pressure or heart rate. BK stimulation specifically inhibits neurogenic contractions in patients with urinary symptoms and relieves bladder hyperactivity in vivo without compromising bladder contractile capacity or cardiovascular safety, supporting its potential therapeutic use for relieving bladder overactivity.
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