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Vrooman OPJ, van Kerrebroeck PEV, van Balken MR, van Koeveringe GA, Rahnama'i MS. Nocturia and obstructive sleep apnoea. Nat Rev Urol 2024:10.1038/s41585-024-00887-7. [PMID: 38783115 DOI: 10.1038/s41585-024-00887-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2024] [Indexed: 05/25/2024]
Abstract
Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.
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Affiliation(s)
- Olaf P J Vrooman
- Department of Urology, Hospital Rijnstate Arnhem, Arnhem, Netherlands.
| | | | | | | | - Mohammad S Rahnama'i
- Department of Urology Nij Smellinghe Hospital, Drachten, Netherlands
- Society of Urological research and education (SURE), Maastricht, Netherlands
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2
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Cho KJ, Kim JC. Novel pharmacotherapeutic avenues for bladder storage dysfunction in men. Expert Opin Pharmacother 2024; 25:585-594. [PMID: 38651268 DOI: 10.1080/14656566.2024.2346278] [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: 02/21/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
INTRODUCTION Bladder storage dysfunction is associated with low quality of life in men and remains a challenging field in pharmacotherapy because of low persistence followed by patient-perceived lack of efficacy and adverse effects. The persistent desire for the development of novel pharmacotherapy is evident, leading to numerous research efforts based on its pathophysiology. AREAS COVERED This review describes the pathophysiology, current pharmacotherapeutic strategies, and emerging novel drugs for male bladder storage dysfunction. The section on emerging pharmacotherapy provides an overview of current research, focusing on high-potential target molecules, particularly those being evaluated in ongoing clinical trials. EXPERT OPINION As pharmacotherapies targeting alpha-adrenergic, beta-adrenergic, and muscarinic receptors - the current primary targets for treating male bladder storage dysfunction - have demonstrated insufficient efficacy and side effects, researchers are exploring various alternative molecular targets. Numerous targets have been identified as central to regulating bladder afferent nerve activity, and their pharmacological effects and potential have been evaluated in animal-based experiments. However, there is a limited number of clinical trials for these new pharmacotherapies, and they have not demonstrated clear superiority over current treatments. Further research is needed to develop new effective pharmacotherapies for bladder storage dysfunction in men.
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Affiliation(s)
- Kang Jun Cho
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon Chul Kim
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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3
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Lu J, Yang B, Zhang W, Cheng H, Zeng J, Wang Y, Wei W, Liu Z. Transplantation of olfactory ensheathing cells can alleviate neuroinflammatory responses in rats with trigeminal neuralgia. Brain Res 2024; 1825:148732. [PMID: 38104922 DOI: 10.1016/j.brainres.2023.148732] [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: 05/12/2023] [Revised: 09/07/2023] [Accepted: 12/14/2023] [Indexed: 12/19/2023]
Abstract
Trigeminal neuralgia (TN) is a common form of facial pain, which primarily manifests as severe pain similar to facial acupuncture and electric shock. Olfactory ensheathing cells (OECs) are glial cells with high bioactivity; these cells are essential for the periodic regeneration of the olfactory nerve and have been utilized for the repair of nerve injuries. A member of the P2X receptor family, P2X7R, is an ion channel type receptor that has been confirmed to participate in various pain response processes. In this study, we transplanted OECs into trigeminal nerve-model rats with distal infraorbital nerve ligation to observe the therapeutic effect of transplanted OECs in rats. Additionally, we utilized the P2X7R-specific inhibitor brilliant blue G (BBG) to study the therapeutic mechanisms of cell transplantation. The facial mechanical pain threshold of these rats significantly increased following cell transplantation. The immunohistochemistry, immunoblotting, and RT-qPCR results demonstrated that the levels of P2X7R, (NOD)-like receptor protein-3 (NLRP3), nuclear factor-κB (NF-κB), interleukin (IL)-1β, and IL-18 in the trigeminal ganglion of rats treated with OEC transplantation or BBG treatment were significantly lower than those in the injured group without treatment. Overall, our results demonstrate that OEC transplantation can alleviate TN in rats, and it can reduce the expression of P2X7R related inflammatory factors in TN rats, reducing neuroinflammatory response in TG.
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Affiliation(s)
- Jiafeng Lu
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Baolin Yang
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Wenjun Zhang
- Rehabilitation Medicine Department, Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Hui Cheng
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Jingnan Zeng
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Yuanli Wang
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Wei Wei
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China
| | - Zengxu Liu
- Department of Anatomy, Basic Medical School, Nanchang University, Nanchang 330006, China.
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Babou Kammoe RB, Sévigny J. Extracellular nucleotides in smooth muscle contraction. Biochem Pharmacol 2024; 220:116005. [PMID: 38142836 DOI: 10.1016/j.bcp.2023.116005] [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: 08/24/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023]
Abstract
Extracellular nucleotides and nucleosides are crucial signalling molecules, eliciting diverse biological responses in almost all organs and tissues. These molecules exert their effects by activating specific nucleotide receptors, which are finely regulated by ectonucleotidases that break down their ligands. In this comprehensive review, we aim to elucidate the relevance of extracellular nucleotides as signalling molecules in the context of smooth muscle contraction, considering the modulatory influence of ectonucleotidases on this intricate process. Specifically, we provide a detailed examination of the involvement of extracellular nucleotides in the contraction of non-vascular smooth muscles, including those found in the urinary bladder, the airways, the reproductive system, and the gastrointestinal tract. Furthermore, we present a broader overview of the role of extracellular nucleotides in vascular smooth muscle contraction.
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Affiliation(s)
- Romuald Brice Babou Kammoe
- Centre de Recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada; Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Jean Sévigny
- Centre de Recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada; Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada.
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Ewerton F, Cruz F, Kapp M, Klein S, Roehm P, Chapple C. Efficacy and Safety of Eliapixant in Overactive Bladder: The 12-Week, Randomised, Placebo-controlled Phase 2a OVADER Study. Eur Urol Focus 2024; 10:90-97. [PMID: 37563004 DOI: 10.1016/j.euf.2023.07.008] [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: 04/21/2023] [Revised: 06/29/2023] [Accepted: 07/24/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND Effective, well-tolerated novel treatments for overactive bladder (OAB) are lacking. The P2X3 receptor antagonist eliapixant demonstrated potential to reduce OAB symptoms in preclinical studies. OBJECTIVE To evaluate the safety, tolerability, and efficacy of eliapixant in patients with OAB with urgency urinary incontinence (UUI). DESIGN, SETTING AND PARTICIPANTS OVADER was a 12-wk, randomised, placebo-controlled, double-blind, parallel-group, multicentre, phase 2a study (NCT04545580) conducted between 2020 and 2022 in private and institutional clinical practices. Eligible patients were aged ≥18 yr with wet OAB symptoms (urgency, urinary frequency, and urinary incontinence) for ≥3 mo before screening. INTERVENTION Randomisation (1:1 ratio) to oral eliapixant 125 mg or placebo twice daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The primary endpoint was the mean change from baseline in the mean number of UUI episodes/24 h over weeks 4, 8, and 12 according to an electronic bladder diary, evaluated using a repeated-measurement model in a Bayesian framework. RESULTS AND LIMITATIONS Of 202 patients enrolled, 85 were valid for per-protocol analysis. The primary efficacy endpoint was not met. The posterior probability for eliapixant superiority over placebo was 40% (point estimate 0.05, 95% credible interval -∞ to 0.38), which did not meet the predefined criterion of ≥90% probability. Secondary and exploratory endpoints were not met. The incidence of adverse events was similar in the eliapixant (n = 32, 63%) and placebo (n = 27, 56%) groups; most were mild and five led to discontinuation of eliapixant. CONCLUSIONS OVADER did not meet its clinical efficacy endpoints. Potential reasons include the nonspecific OAB symptom complex, the poorly understood pathophysiology, and the coinciding COVID-19 pandemic. PATIENT SUMMARY We tested whether a new drug called eliapixant would reduce symptoms of overactive bladder in comparison to placebo. We found that the drug did not work. More knowledge on how overactive bladder occurs is needed to find new drugs to treat this condition.
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Affiliation(s)
| | - Francisco Cruz
- Department of Urology, São João University Hospital Centre, Porto, Portugal; Faculty of Medicine and I3S Institute for Investigation and Innovation in Health, University of Porto, Porto, Portugal
| | | | | | | | - Christopher Chapple
- Department of Urology, Royal Hallamshire Hospital, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK
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Li X, Hu J, Yin P, Liu L, Chen Y. Mechanotransduction in the urothelium: ATP signalling and mechanoreceptors. Heliyon 2023; 9:e19427. [PMID: 37674847 PMCID: PMC10477517 DOI: 10.1016/j.heliyon.2023.e19427] [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: 04/23/2023] [Revised: 08/10/2023] [Accepted: 08/22/2023] [Indexed: 09/08/2023] Open
Abstract
The urothelium, which covers the inner surface of the bladder, is continuously exposed to a complex physical environment where it is stimulated by, and responds to, a wide range of mechanical cues. Mechanically activated ion channels endow the urothelium with functioning in the conversion of mechanical stimuli into biochemical events that influence the surface of the urothelium itself as well as suburothelial tissues, including afferent nerve fibres, interstitial cells of Cajal and detrusor smooth muscle cells, to ensure normal urinary function during the cycle of filling and voiding. However, under prolonged and abnormal loading conditions, the urothelial sensory system can become maladaptive, leading to the development of bladder dysfunction. In this review, we summarize developments in the understanding of urothelial mechanotransduction from two perspectives: first, with regard to the functions of urothelial mechanotransduction, particularly stretch-mediated ATP signalling and the regulation of urothelial surface area; and secondly, with regard to the mechanoreceptors present in the urothelium, primarily transient receptor potential channels and mechanosensitive Piezo channels, and the potential pathophysiological role of these channels in the bladder. A more thorough understanding of urothelial mechanotransduction function may inspire the development of new therapeutic strategies for lower urinary tract diseases.
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Affiliation(s)
| | | | - Ping Yin
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Lumin Liu
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Yuelai Chen
- Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
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7
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Liao Y, Du X, Fu Y, Liu L, Wei J, An Q, Luo X, Gao F, Jia S, Chang Y, Guo M, Liu H. Mechanism of traditional Chinese medicine in treating overactive bladder. Int Urol Nephrol 2023; 55:489-501. [PMID: 36479677 PMCID: PMC9957912 DOI: 10.1007/s11255-022-03434-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
Overactive bladder syndrome (OAB) has made increasing progress in mechanism and treatment research. Traditional Chinese medicine (TCM) is a common complementary therapy for OAB, and it has been found to be effective. However, the intervention mechanism of TCM in the treatment of OAB is still unclear. The aim of this review is to consolidate the current knowledge about the mechanism of TCM: acupuncture, moxibustion, herbs in treating OAB, and the animal models of OAB commonly used in TCM. Finally, we put forward the dilemma of TCM treatment of OAB and discussed the insufficiency and future direction of TCM treatment of OAB.
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Affiliation(s)
- Yuxiang Liao
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China
| | - Xin Du
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China
| | - Yuanbo Fu
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China
| | - Lu Liu
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China
| | - Jiangyan Wei
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China
| | - Qi An
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Xuanzhi Luo
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Fan Gao
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Shuhan Jia
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Ying Chang
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Mengxi Guo
- Beijing University of Chinese Medicine, Beijing, People's Republic of China
| | - Huilin Liu
- Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine, Beijing Key Laboratory of Acupuncture Neuromodulation, Capital Medical University, Beijing, People's Republic of China.
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8
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Urinary ATP Levels Are Controlled by Nucleotidases Released from the Urothelium in a Regulated Manner. Metabolites 2022; 13:metabo13010030. [PMID: 36676954 PMCID: PMC9862892 DOI: 10.3390/metabo13010030] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Adenosine 5′-triphosphate (ATP) is released in the bladder lumen during filling. Urothelial ATP is presumed to regulate bladder excitability. Urinary ATP is suggested as a urinary biomarker of bladder dysfunctions since ATP is increased in the urine of patients with overactive bladder, interstitial cystitis or bladder pain syndrome. Altered urinary ATP might also be associated with voiding dysfunctions linked to disease states associated with metabolic syndrome. Extracellular ATP levels are determined by ATP release and ATP hydrolysis by membrane-bound and soluble nucleotidases (s-NTDs). It is currently unknown whether s-NTDs regulate urinary ATP. Using etheno-ATP substrate and HPLC-FLD detection techniques, we found that s-NTDs are released in the lumen of ex vivo mouse detrusor-free bladders. Capillary immunoelectrophoresis by ProteinSimple Wes determined that intraluminal solutions (ILS) collected at the end of filling contain ENTPD3 > ENPP1 > ENPP3 ≥ ENTPD2 = NT5E = ALPL/TNAP. Activation of adenylyl cyclase with forskolin increased luminal s-NTDs release whereas the AC inhibitor SQ22536 had no effect. In contrast, forskolin reduced and SQ22536 increased s-NTDs release in the lamina propria. Adenosine enhanced s-NTDs release and accelerated ATP hydrolysis in ILS and lamina propria. Therefore, there is a regulated release of s-NTDs in the bladder lumen during filling. Aberrant release or functions of urothelial s-NTDs might cause elevated urinary ATP in conditions with abnormal bladder excitability.
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Aresta Branco MSL, Gutierrez Cruz A, Dayton J, Perrino BA, Mutafova-Yambolieva VN. Mechanosensitive Hydrolysis of ATP and ADP in Lamina Propria of the Murine Bladder by Membrane-Bound and Soluble Nucleotidases. Front Physiol 2022; 13:918100. [PMID: 35784885 PMCID: PMC9246094 DOI: 10.3389/fphys.2022.918100] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/26/2022] [Indexed: 12/02/2022] Open
Abstract
Prior studies suggest that urothelium-released adenosine 5′-triphosphate (ATP) has a prominent role in bladder mechanotransduction. Urothelial ATP regulates the micturition cycle through activation of purinergic receptors that are expressed in many cell types in the lamina propria (LP), including afferent neurons, and might also be important for direct mechanosensitive signaling between urothelium and detrusor. The excitatory action of ATP is terminated by enzymatic hydrolysis, which subsequently produces bioactive metabolites. We examined possible mechanosensitive mechanisms of ATP hydrolysis in the LP by determining the degradation of 1,N6-etheno-ATP (eATP) at the anti-luminal side of nondistended (empty) or distended (full) murine (C57BL/6J) detrusor-free bladder model, using HPLC. The hydrolysis of eATP and eADP was greater in contact with LP of distended than of nondistended bladders whereas the hydrolysis of eAMP remained unchanged during filling, suggesting that some steps of eATP hydrolysis in the LP are mechanosensitive. eATP and eADP were also catabolized in extraluminal solutions (ELS) that were in contact with the LP of detrusor-free bladders, but removed from the organ chambers prior to addition of substrate. The degradation of both purines was greater in ELS from distended than from nondistended preparations, suggesting the presence of mechanosensitive release of soluble nucleotidases in the LP. The released enzyme activities were affected differently by Ca2+ and Mg2+. The common nucleotidase inhibitors ARL67156, POM-1, PSB06126, and ENPP1 Inhibitor C, but not the alkaline phosphatase inhibitor (-)-p-bromotetramisole oxalate, inhibited the enzymes released during bladder distention. Membrane-bound nucleotidases were identified in tissue homogenates and in concentrated ELS from distended preparations by Wes immunodetection. The relative distribution of nucleotidases was ENTPD1 >> ENPP1 > ENTPD2 = ENTPD3 > ENPP3 = NT5E >> ENTPD8 = TNAP in urothelium and ENTPD1 >> ENTPD3 >> ENPP3 > ENPP1 = ENTPD2 = NT5E >> ENTPD8 = TNAP in concentrated ELS, suggesting that regulated ectodomain shedding of membrane-bound nucleotidases possibly occurs in the LP during bladder filling. Mechanosensitive degradation of ATP and ADP by membrane-bound and soluble nucleotidases in the LP diminishes the availability of excitatory purines in the LP at the end of bladder filling. This might be a safeguard mechanism to prevent over-excitability of the bladder. Proper proportions of excitatory and inhibitory purines in the bladder wall are determined by distention-associated purine release and purine metabolism.
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Dietary salt with nitric oxide deficiency induces nocturnal polyuria in mice via hyperactivation of intrarenal angiotensin II-SPAK-NCC pathway. Commun Biol 2022; 5:175. [PMID: 35228649 PMCID: PMC8885931 DOI: 10.1038/s42003-022-03104-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/01/2022] [Indexed: 11/12/2022] Open
Abstract
Nocturnal polyuria is the most frequent cause of nocturia, a common disease associated with a compromised quality of life and increased mortality. Its pathogenesis is complex, and the detailed underlying mechanism remains unknown. Herein, we report that concomitant intake of a high-salt diet and reduced nitric oxide (NO) production achieved through Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) administration in mice resulted in nocturnal polyuria recapitulating the clinical features in humans. High salt intake under reduced NO production overactivated the angiotensin II-SPAK (STE20/SPS1-related proline–alanine-rich protein kinase)-NCC (sodium chloride co-transporter) pathway in the kidney, resulting in the insufficient excretion of sodium during the day and its excessive excretion at night. Excessive Na excretion at night in turn leads to nocturnal polyuria due to osmotic diuresis. Our study identified a central role for the intrarenal angiotensin II-SPAK-NCC pathway in the pathophysiology of nocturnal polyuria, highlighting its potential as a promising therapeutic target. This study reports a mouse model of nocturnal polyuria - increased urine production at night that causes compromised quality of life and may impact mortality in older people. The authors identify a molecular pathway in the kidney that could prove to be a promising drug target for nocturnal polyuria.
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Fry CH, McCloskey KD. Purinergic signalling in the urinary bladder - When function becomes dysfunction. Auton Neurosci 2021; 235:102852. [PMID: 34329833 DOI: 10.1016/j.autneu.2021.102852] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/16/2021] [Accepted: 07/07/2021] [Indexed: 01/23/2023]
Abstract
Knowledge of the participation of ATP and related purines in urinary tract physiology has been established over the last five decades through the work of many independent groups, inspired by, and building on the pioneering studies of Professor Geoffrey Burnstock and his coworkers. As part of a series of reviews in this tribute edition, the present article summarises our current understanding of purines and purinergic signalling in modulating and regulating urinary tract function. Purinergic mechanisms underlying the origin of bladder pain; sensations of bladder filling and urinary tract motility; and regulation of detrusor smooth muscle contraction are described, encompassing the relevant history of discovery and consolidation of knowledge as methodologies and pharmacological tools have developed. We consider normal physiology, including development and ageing and then move to pathophysiology, discussing the causal and consequential contribution of purinergic signalling mechanism and their constituent components (receptors, signal transduction, effector molecules) to bladder dysfunction.
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Affiliation(s)
- Christopher H Fry
- School of Physiology, Pharmacology & Neuroscience, Faculty of Health Sciences, University of Bristol, Bristol, UK.
| | - Karen D McCloskey
- Patrick G Johnston Centre for Cancer Research, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK.
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Okuyama E, Kawatani M, Hashimoto J, Tanimoto K, Hashimoto M, Matsumoto‐Miyai K. The nitric oxide-cyclic guanosine monophosphate pathway inhibits the bladder ATP release in response to a physiological or pathological stimulus. Physiol Rep 2021; 9:e14938. [PMID: 34288526 PMCID: PMC8290832 DOI: 10.14814/phy2.14938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/18/2021] [Accepted: 05/29/2021] [Indexed: 11/24/2022] Open
Abstract
The release of ATP from the epithelium of the urinary bladder (urothelium) in response to mechanical/chemical stimuli contributes to the visceral sensation in the micturition reflex. The nitric oxide (NO)-mediated induction of cyclic guanosine monophosphate (cGMP) has been detected in urothelial cells and may inhibit the micturition reflex. However, the function of the NO-cGMP pathway in the regulation of urothelial ATP release remains poorly understood in contrast to its effects on smooth muscles or primary afferent nerves. Therefore, we investigated the relevance of the NO-cGMP pathway to ATP release on the mucosal side in the present study. The administration of l-arginine (NO precursor) or NOC 12 (NO donor) significantly reduced ATP release to the mucosal side at a physiologically normal urine storage pressure (5 cmH2 O). L-NAME (NO synthase inhibitor) significantly increased the distention-induced release of ATP. The phosphodiesterase-5 inhibitor, sildenafil, which increases cGMP levels, inhibited distention-induced ATP release. Furthermore, sildenafil significantly reduced ATP release in response to the administration of lipopolysaccharide. These results suggest that the NO-cGMP pathway inhibited urothelial ATP release during the storage phase under both physiological and pathological conditions.
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Affiliation(s)
- Eriko Okuyama
- Department of RadiologyAkita University Graduate School of MedicineAkitaJapan
| | - Masahito Kawatani
- Department of NeurophysiologyAkita University Graduate School of MedicineAkitaJapan
| | - Junichi Hashimoto
- Graduate School of Comprehensive RehabilitationOsaka Prefecture UniversityHabikinoOsakaJapan
| | - Keisuke Tanimoto
- Graduate School of Comprehensive RehabilitationOsaka Prefecture UniversityHabikinoOsakaJapan
| | - Manabu Hashimoto
- Department of RadiologyAkita University Graduate School of MedicineAkitaJapan
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Chakrabarty B. The role of the bladder urothelium as a chemical-neural transducer via purinergic signalling in the rapid defence against bacterial infection. Purinergic Signal 2021; 17:327-329. [PMID: 33959873 DOI: 10.1007/s11302-021-09794-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 04/29/2021] [Indexed: 10/21/2022] Open
Affiliation(s)
- Basu Chakrabarty
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
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Urothelium-Specific Deletion of Connexin43 in the Mouse Urinary Bladder Alters Distension-Induced ATP Release and Voiding Behavior. Int J Mol Sci 2021; 22:ijms22041594. [PMID: 33562445 PMCID: PMC7914662 DOI: 10.3390/ijms22041594] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 12/19/2022] Open
Abstract
Connexin43 (Cx43), the main gap junction and hemichannel forming protein in the urinary bladder, participates in the regulation of bladder motor and sensory functions and has been reported as an important modulator of day-night variations in functional bladder capacity. However, because Cx43 is expressed throughout the bladder, the actual role played by the detrusor and the urothelial Cx43 is still unknown. For this purpose, we generated urothelium-specific Cx43 knockout (uCx43KO) mice using Cre-LoxP system. We evaluated the day-night micturition pattern and the urothelial Cx43 hemichannel function of the uCx43KO mice by measuring luminal ATP release after bladder distention. In wild-type (WT) mice, distention-induced ATP release was elevated, and functional bladder capacity was decreased in the animals' active phase (nighttime) when Cx43 expression was also high compared to levels measured in the sleep phase (daytime). These day-night differences in urothelial ATP release and functional bladder capacity were attenuated in uCx43KO mice that, in the active phase, displayed lower ATP release and higher functional bladder capacity than WT mice. These findings indicate that urothelial Cx43 mediated ATP signaling and coordination of urothelial activity are essential for proper perception and regulation of responses to bladder distension in the animals' awake, active phase.
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15
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Bladder urothelium converts bacterial lipopolysaccharide information into neural signaling via an ATP-mediated pathway to enhance the micturition reflex for rapid defense. Sci Rep 2020; 10:21167. [PMID: 33273625 PMCID: PMC7713076 DOI: 10.1038/s41598-020-78398-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
When bacteria enter the bladder lumen, a first-stage active defensive mechanism flushes them out. Although urinary frequency induced by bacterial cystitis is a well-known defensive response against bacteria, the underlying mechanism remains unclear. In this study, using a mouse model of acute bacterial cystitis, we demonstrate that the bladder urothelium senses luminal extracellular bacterial lipopolysaccharide (LPS) through Toll-like receptor 4 and releases the transmitter ATP. Moreover, analysis of purinergic P2X2 and P2X3 receptor-deficient mice indicated that ATP signaling plays a pivotal role in the LPS-induced activation of L6–S1 spinal neurons through the bladder afferent pathway, resulting in rapid onset of the enhanced micturition reflex. Thus, we revealed a novel defensive mechanism against bacterial infection via an epithelial-neural interaction that induces urinary frequency prior to bacterial clearance by neutrophils of the innate immune system. Our results indicate an important defense role for the bladder urothelium as a chemical-neural transducer, converting bacterial LPS information into neural signaling via an ATP-mediated pathway, with bladder urothelial cells acting as sensory receptor cells.
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16
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Eljamal K, Kajioka S, Maki T, Ushijima M, Kawagoe K, Lee K, Sasaguri T. New mouse model of underactive bladder developed by placement of a metal ring around the bladder neck. Low Urin Tract Symptoms 2020; 13:299-307. [PMID: 33089671 DOI: 10.1111/luts.12359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/30/2020] [Accepted: 10/04/2020] [Indexed: 01/22/2023]
Abstract
OBJECTIVE To develop a new mouse model of underactive bladder (UAB) caused by chronic bladder outlet obstruction (BOO). METHODS BOO was created in 6-week-old male C57BL/6 mice using surgery to loosely place a silver jump ring around the bladder neck of each mouse. Micturition behavior (assessed with a metabolic cage) and cystometry were used to evaluate bladder function at 8 and 16 weeks after BOO. Following completion of the functional studies, the bladders of the mice were excised, weighed, and subjected to histological analysis. RESULTS Micturition behavior analysis showed that mice subjected to BOO for 16 weeks had a lower frequency of micturition (7.3 ± 1.1 vs 12.5 ± 3.0 times/d, P < .05) and volume per void (106.0 ± 0.1 vs 133.9 ± 3.2 μL, P < .05) than mice subjected to BOO for 8 weeks. Cystometry revealed that mice subjected to BOO for 16 weeks had lower baseline pressure (8.4 ± 0.6 vs 14.0 ± 0.7 cmH2 O, P < .01) and micturition pressure (13.9 ± 1.1 vs 42.8 ± 1.7 cmH2 O, P < .05) than mice subjected to BOO for 8 weeks. BOO caused progressive increases in bladder mass and collagen deposition over time. CONCLUSIONS We successfully established a novel mouse model of UAB using surgery to place a silver jump ring loosely on the bladder neck. BOO initially induced bladder overactivity but subsequently resulted in UAB due to deterioration of detrusor smooth muscle contractility and progressive deposition of collagen in the bladder wall.
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Affiliation(s)
- Kareman Eljamal
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shunichi Kajioka
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.,Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomoko Maki
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Miho Ushijima
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kentaro Kawagoe
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ken Lee
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toshiyuki Sasaguri
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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17
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PIEZO2 in sensory neurons and urothelial cells coordinates urination. Nature 2020; 588:290-295. [PMID: 33057202 PMCID: PMC7725878 DOI: 10.1038/s41586-020-2830-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/22/2020] [Indexed: 11/24/2022]
Abstract
Henry Miller stated that “to relieve a full bladder is one of the great human joys”. Urination is critically important in health, and ailments of the lower urinary tract (LUT) cause extensive pathological burden. Nevertheless, we take urination for granted, and in-depth mechanistic insight is lacking. We have witnessed advances in understanding the central circuitry in the brain that facilitates urination1–3. Beyond central control, micturition reflexes that govern urination are all initiated by peripheral mechanical stimuli such as bladder stretch and urethral flow4. Surprisingly, the mechanotransduction molecules and the cell types that function as the primary stretch and pressure detectors in the urinary tract are mostly unknown. We find that the mechanosensitive ion channel PIEZO2 is expressed in lower urinary tract tissues, where it is required for low-threshold bladder stretch sensing and urethral micturition reflexes. We show that PIEZO2 acts as a sensor in both the bladder urothelium and innervating sensory neurons. Importantly, both humans and mice lacking functional PIEZO2 have impaired bladder control, and humans report deficient bladder-filling sensation. This study pinpoints PIEZO2 as a key mechanosensor in urinary function. These findings enable future work that will unlock how urothelial cells and sensory neurons interact to control urination.
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18
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Voiding Dysfunction in Old Male Rats Associated With Enlarged Prostate and Irregular Afferent-Triggered Reflex Responses. Int Neurourol J 2020; 24:258-269. [PMID: 33017896 PMCID: PMC7538283 DOI: 10.5213/inj.2040114.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/24/2020] [Indexed: 11/08/2022] Open
Abstract
Purpose This study was conducted to evaluate the hypothesis that an enlarged prostate in old rats may lead to complications associated with voiding dysfunction involving ionotropic P2X2/3-type purinergic receptors Methods Intact animals were divided into male young (MYR; 8–10 weeks old) and male old (MOR; 20 months old) rats. The animals underwent simultaneous detrusor electromyography (EMG) and suprapubic cystometry (CMG) under urethane anesthesia. Immunofluorescence techniques were used to evaluate prostatic autonomic innervation and P2X3R expression in bladder urothelial cells. The functional role of P2X3R was characterized by intramuscular application of AF-353, a selective P2X2/3R antagonist. Results The prostate index significantly increased in MOR, suggestive of an enlarged prostate affecting micturition patterns. Significant EMG and CMG differences were found between MYR and MOR. Higher immunoreactivity for P2X2/3R in the urothelial layer and for prostatic neurofilaments was seen in MOR. Systemic inhibition of P2X2/3R had minimal effects on MYR responsiveness, but improved voiding function in MOR with a marked decrease of intravesical pressure and bladder contractile responses. Conclusions The data support the hypothesis that an enlarged prostate in MOR may contribute to voiding dysfunction involving activation of P2X2/3R, which enhances a prostate-bladder reflex. This reflex may increase bladder afferent transmission and activation of increased prostate innervation, leading to voiding dysfunction.
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19
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Dalghi MG, Montalbetti N, Carattino MD, Apodaca G. The Urothelium: Life in a Liquid Environment. Physiol Rev 2020; 100:1621-1705. [PMID: 32191559 PMCID: PMC7717127 DOI: 10.1152/physrev.00041.2019] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/02/2020] [Accepted: 03/14/2020] [Indexed: 02/08/2023] Open
Abstract
The urothelium, which lines the renal pelvis, ureters, urinary bladder, and proximal urethra, forms a high-resistance but adaptable barrier that surveils its mechanochemical environment and communicates changes to underlying tissues including afferent nerve fibers and the smooth muscle. The goal of this review is to summarize new insights into urothelial biology and function that have occurred in the past decade. After familiarizing the reader with key aspects of urothelial histology, we describe new insights into urothelial development and regeneration. This is followed by an extended discussion of urothelial barrier function, including information about the roles of the glycocalyx, ion and water transport, tight junctions, and the cellular and tissue shape changes and other adaptations that accompany expansion and contraction of the lower urinary tract. We also explore evidence that the urothelium can alter the water and solute composition of urine during normal physiology and in response to overdistension. We complete the review by providing an overview of our current knowledge about the urothelial environment, discussing the sensor and transducer functions of the urothelium, exploring the role of circadian rhythms in urothelial gene expression, and describing novel research tools that are likely to further advance our understanding of urothelial biology.
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Affiliation(s)
- Marianela G Dalghi
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Nicolas Montalbetti
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Marcelo D Carattino
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Gerard Apodaca
- Department of Medicine, Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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20
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Stenqvist J, Aronsson P, Carlsson T, Winder M, Tobin G. In vivo paracrine effects of ATP-induced urothelial acetylcholine in the rat urinary bladder. Auton Neurosci 2020; 227:102689. [PMID: 32473532 DOI: 10.1016/j.autneu.2020.102689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 01/23/2023]
Abstract
Mechanical stretch of the urothelium induces the release of ATP that activates bladder afferent nerves. In the rat urinary bladder, ATP is also a contractile co-transmitter in the parasympathetic innervation. In isolated preparations, ATP evokes a urothelial release of acetylcholine that substantially contributes to ATP-evoked contractile responses. Currently we aimed to further examine the interactions of ATP and acetylcholine in the rat urinary bladder in two in vivo models. In the whole bladder preparation, atropine reduced ATP-evoked responses by about 50% in intact but denervated bladders, while atropine had no effect after denudation of the urothelium. In a split bladder preparation, reflex-evoked responses of the contralateral half were studied by applying stimuli (agonists or stretch) to the ipsilateral half. Topical administration of ATP and methacholine as well as of stretch induced contralateral reflex-evoked contractions. While topical administration of atropine ipsilaterally reduced the ATP- and stretch-induced contralateral contractions by 27 and 39%, respectively, the P2X purinoceptor antagonist PPADS reduced them by 74 and 84%. In contrary, the muscarinic M2-(M4)-selective receptor antagonist methoctramine increased the responses by 38% (ATP) and 75% (stretch). Pirenzepine (M1-selective antagonist) had no effect on the reflex. In vitro, in the absence of the reflex, methoctramine did not affect the ATP-induced responses. It is concluded that urothelial ATP potently induces the micturition reflex and stimulates urothelial release of acetylcholine. Acetylcholine subsequently acts on afferents and on the detrusor muscle. While muscarinic M2 and/or M4 receptors in the sensory innervation exert inhibitory modulation, muscarinic M3 receptors cause excitation.
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Affiliation(s)
- Johanna Stenqvist
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Patrik Aronsson
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Thomas Carlsson
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Michael Winder
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden
| | - Gunnar Tobin
- Department of Pharmacology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Box 431, 405 30 Gothenburg, Sweden.
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21
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Okamoto T, Hatakeyama S, Imai A, Yamamoto H, Yoneyama T, Mori K, Yoneyama T, Hashimoto Y, Nakaji S, Ohyama C. The association between serum serotonin levels and overactive bladder: results from a community-based cross-sectional study in Japan. World J Urol 2020; 39:169-175. [PMID: 32193653 DOI: 10.1007/s00345-020-03167-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/10/2020] [Indexed: 10/24/2022] Open
Abstract
PURPOSE To investigate the association between serum serotonin (5-HT) levels and overactive bladder (OAB) in a community-dwelling population. METHODS This cross-sectional study analyzed 1024 subjects who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. OAB was assessed using the Overactive Bladder Symptom Score (OABSS). OAB was defined as an occurrence of urinary urgency at least once a week and an OABSS of ≥ 3. We assessed serum 5-HT levels, laboratory data, and comorbidities of each participants. Participants' mental health status was evaluated using the Center for Epidemiologic Studies Depression (CES-D) scale. The association of serum 5-HT levels and OAB was analyzed by multivariable logistic regression analysis. RESULTS This study included 394 men and 630 women. Of those, 118 (44 male and 74 female) were OAB sufferers. There were significant group differences in age, history of cardiovascular disease, chronic kidney disease, hypertension, diabetes mellitus, and CES-D score. Participants' serum 5-HT levels in the OAB group were significantly lower than those in the non-OAB group (100 vs. 127 ng/mL, P < 0.001). Multivariable analysis showed that age (odds ratio [OR]; 1.06, 95% confidence interval [CI]; 1.04-1.08, P < 0.001) and log serum 5-HT level (OR; 0.25, 95% CI; 0.10-0.68, P = 0.006) were independently associated with OAB. CONCLUSIONS Lower serum 5-HT levels could independently be associated with the presence of OAB. Further study is necessary to elucidate a possible causal relationship between serum 5-HT levels and OAB.
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Affiliation(s)
- Teppei Okamoto
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Shingo Hatakeyama
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.
| | - Atsushi Imai
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Hayato Yamamoto
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Tohru Yoneyama
- Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kazuyuki Mori
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Takahiro Yoneyama
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Yasuhiro Hashimoto
- Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Shigeyuki Nakaji
- Department of Social Medicine, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan
| | - Chikara Ohyama
- Department of Urology, Hirosaki University Graduate School of Medicine, 5 Zaifu-chou, Hirosaki, 036-8562, Japan.,Department of Advanced Transplant and Regenerative Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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22
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Salazar BH, Hoffman KA, Zhang C, Zhang Y, Cruz Y, Boone TB, Munoz A. Modulatory effects of intravesical P2X2/3 purinergic receptor inhibition on lower urinary tract electromyographic properties and voiding function of female rats with moderate or severe spinal cord injury. BJU Int 2019; 123:538-547. [PMID: 30255543 PMCID: PMC6715153 DOI: 10.1111/bju.14561] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVES To evaluate the role that intravesical P2X2/3 purinergic receptors (P2X2/3Rs) play in early and advanced neurogenic lower urinary tract (LUT) dysfunction after contusion spinal cord injury (SCI) in female rats. MATERIALS AND METHODS Female Sprague-Dawley rats received a thoracic Th8/Th9 spinal cord contusion with either force of 100 kDy (cN); moderate) or 150 kDy (cN; severe); Sham rats had no injury. Evaluations on urethane-anesthetised rats were conducted at either 2 or 4 weeks after SCI. LUT electrical signals and changes in bladder pressure were simultaneously recorded using cystometry and a set of custom-made flexible microelectrodes, before and after intravesical application of the P2X2/3R antagonist AF-353 (10 μM), to determine the contribution of P2X2/3R-mediated LUT modulation. RESULTS Severe SCI significantly increased bladder contraction frequency, and reduced both bladder pressure amplitude and intraluminal-pressure high-frequency oscillations (IPHFO). Intravesical P2X2/3R inhibition did not modify bladder pressure or IPHFO in the Sham and moderate-SCI rats, although did increase the intercontractile interval (ICI). At 2 weeks after SCI, the Sham and moderate-SCI rats had significant LUT electromyographic activity during voiding, with a noticeable reduction in LUT electrical signals seen at 4 weeks after SCI. Intravesical inhibition of P2X2/3R increased the ICI in the Sham and moderate-SCI rats at both time-points, but had no effect on rats with severe SCI. The external urethral sphincter (EUS) showed strong and P2X2/3R-independent electrical signals in the Sham and moderate-SCI rats in the early SCI stage. At 4 weeks after SCI, the responsiveness of the EUS was significantly attenuated, independently of SCI intensity. CONCLUSIONS This study shows that electrophysiological properties of the LUT are progressively impaired depending on SCI intensity and that intravesical P2X2/3R inhibition can attenuate electrical activity in the neurogenic LUT at early, but not at semi-chronic SCI. This translational study should be useful for planning clinical evaluations.
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Affiliation(s)
- Betsy H. Salazar
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
| | - Kristopher A. Hoffman
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
| | - Chuan Zhang
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Biomedical Engineering University of Houston
- Guangdong Provincial Work Injury Rehabilitation Hospital, Guangdong, China
| | - Yingchun Zhang
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Biomedical Engineering University of Houston
- Guangdong Provincial Work Injury Rehabilitation Hospital, Guangdong, China
| | - Yolanda Cruz
- Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, México
| | - Timothy B. Boone
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Department of Urology, Houston Methodist Hospital
| | - Alvaro Munoz
- Regenerative Medicine and Tissue Engineering Program-Urology, Houston Methodist Research Institute
- Centro Universitario del Norte, Universidad de Guadalajara, Colotlán, México
- Corresponding Author: Alvaro Munoz, PhD, Current affiliation: Centro Universitario del Norte, Universidad de Guadalajara, Carretera Federal No. 23, Km. 191, C.P. 46200, Colotlán, Jalisco, México., / Tel: +52-33-1058-5200 (Ext. 33679) / Fax: +1713-441-6463
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23
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Umans BD, Liberles SD. Neural Sensing of Organ Volume. Trends Neurosci 2018; 41:911-924. [PMID: 30143276 PMCID: PMC6252275 DOI: 10.1016/j.tins.2018.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/11/2018] [Accepted: 07/12/2018] [Indexed: 01/04/2023]
Abstract
Many internal organs change volume periodically. For example, the stomach accommodates ingested food and drink, the bladder stores urine, the heart fills with blood, and the lungs expand with every breath. Specialized peripheral sensory neurons function as mechanoreceptors that detect tissue stretch to infer changes in organ volume and then relay this information to the brain. Central neural circuits process this information and evoke perceptions (satiety, nausea), control physiology (breathing, heart rate), and impact behavior (feeding, micturition). Yet, basic questions remain about how neurons sense organ distension and whether common sensory motifs are involved across organs. Here, we review candidate mechanosensory receptors, cell types, and neural circuits, focusing on the stomach, bladder, and airways. Understanding mechanisms of organ stretch sensation may provide new ways to treat autonomic dysfunction.
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Affiliation(s)
- Benjamin D Umans
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Stephen D Liberles
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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24
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Ueda N, Kondo M, Takezawa K, Kiuchi H, Sekii Y, Inagaki Y, Soda T, Fukuhara S, Fujita K, Uemura M, Imamura R, Miyagawa Y, Nonomura N, Shimada S. Intravesical ATP instillation induces urinary frequency because of activation of bladder afferent nerves without inflammatory changes in mice: A promising model for overactive bladder. Biochem Biophys Res Commun 2018; 506:498-503. [PMID: 30361095 DOI: 10.1016/j.bbrc.2018.10.106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 10/17/2018] [Indexed: 11/28/2022]
Abstract
ATP in the suburothelial layer is released from the bladder urothelium by mechanical stimuli. ATP directly activates purinergic receptors that are expressed on primary bladder afferent neurons and induces the micturition reflex. Although ATP is also released to the bladder lumen from the bladder urothelium, the role of ATP in the bladder lumen is unknown. Recently, clinical studies have reported that urinary ATP levels are much higher in patients with an overactive bladder than healthy controls. These results suggest that ATP in the bladder lumen is also involved in the micturition reflex. In this study, we performed intravesical ATP instillation in the mouse bladder. We evaluated urinary function with novel reliable methods using improved cystometry and ultrasonography, which we previously established. We found that intravesical ATP instillation induced urinary frequency because of activation of bladder afferent nerves without inflammatory changes in the bladder or an increase in post-void residual urine. These results suggest that not only ATP in the suburothelial layer, but also ATP in the bladder lumen, are involved in enhancement of the micturition reflex.
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Affiliation(s)
- Norichika Ueda
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan; Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Makoto Kondo
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
| | - Kentaro Takezawa
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Hiroshi Kiuchi
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yosuke Sekii
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yusuke Inagaki
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Tetsuji Soda
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Shinichiro Fukuhara
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Kazutoshi Fujita
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Motohide Uemura
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Ryoichi Imamura
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Yasushi Miyagawa
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Norio Nonomura
- Department of Urology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
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25
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Sidler M, Aitken KJ, Forward S, Vitkin A, Bagli DJ. Non-invasive voiding assessment in conscious mice. Bladder (San Franc) 2018; 5:e33. [PMID: 32775475 PMCID: PMC7401987 DOI: 10.14440/bladder.2018.582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/15/2017] [Accepted: 01/22/2017] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To review available options of assessing murine bladder function and to evaluate a non-invasive technique suitable for long-term recording. METHODS We reviewed previously described methods to record rodent bladder function. We used modified metabolic cages to capture novel recording tracings of mouse micturition. We evaluated our method in a pilot study with female mice undergoing partial bladder outlet obstruction or sham operation, respectively; half of the partial obstruction and sham group received treatment with an S6K-inhibitor, targeting the mTOR pathway, which is known to be implicated in bladder response to obstruction. RESULTS Our non-invasive method using continuous urine weight recording reliably detected changes in murine bladder function resulting from partial bladder outlet obstruction or treatment with S6K-inhibitor. We found obstruction as well as treatment with S6K-inhibitor to correlate with a hyperactive voiding pattern. CONCLUSIONS While invasive methods to assess murine bladder function largely disturb bladder histology and intrinsically render post-cystometry gene expression analysis of questionable value, continuous urine weight recording is a reliable, inexpensive, and critically non-invasive method to assess murine bladder function, suitable for a long-term application.
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Affiliation(s)
- Martin Sidler
- The Hospital for Sick Children, Research Institute, Developmental and Stem Cell Biology, Toronto, Canada.,The Hospital for Sick Children, Pediatric Urology, Toronto, Canada.,Institute of Medical Science, University of Toronto, Canada.,Neonatal and Paediatric Surgery, Great Ormond Street Hospital, London, UK
| | - Karen J Aitken
- The Hospital for Sick Children, Research Institute, Developmental and Stem Cell Biology, Toronto, Canada
| | - Sarah Forward
- Department of Medical Biophysics, University of Toronto, Canada
| | - Alex Vitkin
- Department of Medical Biophysics, University of Toronto, Canada
| | - Darius J Bagli
- The Hospital for Sick Children, Research Institute, Developmental and Stem Cell Biology, Toronto, Canada.,The Hospital for Sick Children, Pediatric Urology, Toronto, Canada.,Institute of Medical Science, University of Toronto, Canada
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Sengiku A, Ueda M, Kono J, Sano T, Nishikawa N, Kunisue S, Tsujihana K, Liou LS, Kanematsu A, Shimba S, Doi M, Okamura H, Ogawa O, Negoro H. Circadian coordination of ATP release in the urothelium via connexin43 hemichannels. Sci Rep 2018; 8:1996. [PMID: 29386573 PMCID: PMC5792455 DOI: 10.1038/s41598-018-20379-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/17/2018] [Indexed: 11/17/2022] Open
Abstract
Day-night changes in the storage capacity of the urinary bladder are indispensable for sound sleep. Connexin 43 (Cx43), a major gap junction protein, forms hemichannels as a pathway of ATP in other cell types, and the urinary bladder utilizes ATP as a mechanotransduction signals to modulate its capacity. Here, we demonstrate that the circadian clock of the urothelium regulates diurnal ATP release through Cx43 hemichannels. Cx43 was expressed in human and mouse urothelium, and clock genes oscillated in the mouse urothelium accompanied by daily cycles in the expression of Cx43 and extracellular ATP release into the bladder lumen. Equivalent chronological changes in Cx43 and ATP were observed in immortalized human urothelial cells, but these diurnal changes were lost in both arrhythmic Bmal1-knockout mice and in BMAL1-knockdown urothelial cells. ATP release was increased by Cx43 overexpression and was decreased in Cx43 knockdown or in the presence of a selective Cx43 hemichannel blocker, which indicated that Cx43 hemichannels are considered part of the components regulating ATP release in the urothelium. Thus, a functional circadian rhythm exists in the urothelium, and coordinates Cx43 expression and function as hemichannels that provide a direct pathway of ATP release for mechanotransduction and signalling in the urothelium.
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Affiliation(s)
- Atsushi Sengiku
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Masakatsu Ueda
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Jin Kono
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Takeshi Sano
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Nobuyuki Nishikawa
- Department of Urology, Japanese Red Cross Otsu Hospital, Shiga, 520-8511, Japan
| | - Sumihiro Kunisue
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | - Kojiro Tsujihana
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
- Department of Dermatology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Louis S Liou
- Department of Urology, Cambridge Health Alliance, Cambridge, MA, 02139, USA
| | - Akihiro Kanematsu
- Department of Urology, Hyogo College of Medicine, Hyogo, 663-8501, Japan
| | - Shigeki Shimba
- Department of Health Science, School of Pharmacy, Nihon University, Chiba, 245-8555, Japan
| | - Masao Doi
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | - Hitoshi Okamura
- Department of Systems Biology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, 606-8501, Japan
| | - Osamu Ogawa
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Hiromitsu Negoro
- Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
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Electrical Activity of the Bladder Is Attenuated by Intravesical Inhibition of P2X2/3 Receptors During Micturition in Female Rats. Int Neurourol J 2017; 21:259-269. [PMID: 29298472 PMCID: PMC5756821 DOI: 10.5213/inj.1734998.499] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 11/27/2017] [Indexed: 01/23/2023] Open
Abstract
Purpose To simultaneously monitor electrical discharges in various bladder regions and the external urethral sphincter (EUS) during voiding contractions, and to assess the functional role of myogenic modulation of the lower urinary tract (LUT) by ionotropic purinergic receptors containing the P2X3 subunit. Methods Female Sprague-Dawley rats were anesthetized with urethane, and implanted with a suprapubic catheter for open cystometry. Flexible microelectrodes were placed ventrally in the bladder dome, upper bladder, lower bladder, and bladder base, along with the middle section of the exposed EUS. Intravesical P2X3-containing receptors were blocked with AF-323, a specific P2X3-P2X2/3 receptor antagonist. A digital electrophysiology amplifier was used to record electrical and cystometric signals throughout the LUT. Results Electrical activity in the LUT started before effective voiding contractions. Bladder pressure and electrical waveforms showed consistent out-of-phase activity when compared with the recordings made at the EUS. This pattern was also observed during voiding contractions in the presence of AF-353, supporting the hypothesis that during bladder distension, activation of P2X3-containing receptors is required for voiding contractions. Furthermore, the inhibition of P2X3-containing receptors significantly decreased the amplitude of electrical signals in the urinary bladder, but not the base or EUS. Conclusions Our results provide novel information about the regulation of the micturition process by P2X3-containing receptors located in the inner layers of the bladder.
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Rocha JN. Extracellular adenosine 5'-triphosphate concentrations changes in rat spinal cord associated with the activation of urinary bladder afferents. A microdialysis study. EINSTEIN-SAO PAULO 2017; 14:541-546. [PMID: 28076603 PMCID: PMC5221382 DOI: 10.1590/s1679-45082016ao3794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/25/2016] [Indexed: 11/22/2022] Open
Abstract
Objective To determine adenosine 5’-triphosphate levels in the interstice of spinal cord L6-S1 segment, under basal conditions or during mechanical and chemical activation of urinary bladder afferents. Methods A microdialysis probe was transversally implanted in the dorsal half of spinal cord L6-S1 segment in female rats. Microdialysate was collected at 15 minutes intervals during 135 minutes, in anesthetized animals. Adenosine 5’-triphosphate concentrations were determined with a bioluminescent assay. In one group of animals (n=7) microdialysate samples were obtained with an empty bladder during a 10-minutes bladder distension to 20 or 40cmH2O with either saline, saline with acetic acid or saline with capsaicin. In another group of animals (n=6) bladder distention was performed and the microdialysis solution contained the ectonucleotidase inhibitor ARL 67156. Results Basal extracellular adenosine triphosphate levels were 110.9±35.34fmol/15 minutes, (mean±SEM, n=13), and bladder distention was associated with a significant increase in adenosine 5’-triphosphate levels which was not observed after bladder distention with saline solution containing capsaicin (10µM). Microdialysis with solution containing ARL 67156 (1mM) was associated with significantly higher extracellular adenosine 5’-triphosphate levels and no further increase in adenosine 5’-triphosphate was observed during bladder distension. Conclusion Adenosine 5’-triphosphate was present in the interstice of L6-S1 spinal cord segments, was degraded by ectonucleotidase, and its concentration increased following the activation of bladder mechanosensitive but not of the chemosensitive afferents fibers. Adenosine 5’-triphosphate may originate either from the central endings of bladder mechanosensitive primary afferent neurons, or most likely from intrinsic spinal neurons, or glial cells and its release appears to be modulated by capsaicin activated bladder primary afferent or by adenosine 5’-triphosphate itself.
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Affiliation(s)
- Jeová Nina Rocha
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
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Zhang X, Gao S, Tanaka M, Zhang Z, Huang Y, Mitsui T, Kamiyama M, Koizumi S, Fan J, Takeda M, Yao J. Carbenoxolone inhibits TRPV4 channel-initiated oxidative urothelial injury and ameliorates cyclophosphamide-induced bladder dysfunction. J Cell Mol Med 2017; 21:1791-1802. [PMID: 28244642 PMCID: PMC5571544 DOI: 10.1111/jcmm.13100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/25/2016] [Indexed: 01/23/2023] Open
Abstract
Carbenoxolone (CBX) is a clinically prescribed drug for the treatment of digestive ulcer and inflammation. It is also a widely used pharmacological inhibitor of several channels in basic research. Given that the overactivity of several channels, including those inhibitable by CBX, underlies bladder dysfunction, we tested the potential therapeutic application and mechanism of CBX in the treatment of voiding dysfunction. In a mouse model of cystitis induced by cyclophosphamide (CYP), CBX administration prevented the CYP‐elicited increase in bladder weight, oedema, haemorrhage, and urothelial injury. CBX also greatly improved micturition pattern, as manifested by the apparently decreased micturition frequency and increased micturition volume. Western blot results showed that CBX suppressed CYP‐induced increase in protein carbonyls, COX‐2, and iNOS. Further analysis using cultured urothelial cells revealed that acrolein, the major metabolite of CYP, caused protein oxidation, p38 activation, and urothelial injury. These effects of acrolein were reproduced by TRPV4 agonists and significantly prevented by antioxidant NAC, p38 inhibitor SB203580, TRPV4 antagonist RN‐1734, and CBX. Further studies showed that CBX potently suppressed TRPV4 agonist‐initiated calcium influx and subsequent cell injury. CBX attenuated CYP‐induced cystitis in vivo and reduced acrolein‐induced cell injury in vitro, through mechanisms involving inhibition of TRPV4 channels and attenuation of the channel‐mediated oxidative stress. CBX might be a promising agent for the treatment of bladder dysfunction.
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Affiliation(s)
- Xiling Zhang
- Division of Molecular Signaling, Department of Advanced Biomedical Research, University of Yamanashi, Yamanashi, Japan.,China Medical University, Shenyang, China
| | - Shan Gao
- Division of Molecular Signaling, Department of Advanced Biomedical Research, University of Yamanashi, Yamanashi, Japan.,China Medical University, Shenyang, China
| | - Masayoshi Tanaka
- Department of Neuropharmacology, University of Yamanashi, Yamanashi, Japan
| | - Zhen Zhang
- Division of Molecular Signaling, Department of Advanced Biomedical Research, University of Yamanashi, Yamanashi, Japan
| | - Yanru Huang
- Division of Molecular Signaling, Department of Advanced Biomedical Research, University of Yamanashi, Yamanashi, Japan
| | - Takahiko Mitsui
- Department of Urology, University of Yamanashi, Yamanashi, Japan
| | - Manabu Kamiyama
- Department of Urology, University of Yamanashi, Yamanashi, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, University of Yamanashi, Yamanashi, Japan
| | - Jianglin Fan
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan
| | - Masayuki Takeda
- Department of Urology, University of Yamanashi, Yamanashi, Japan
| | - Jian Yao
- Division of Molecular Signaling, Department of Advanced Biomedical Research, University of Yamanashi, Yamanashi, Japan
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Takezawa K, Kondo M, Nonomura N, Shimada S. Urothelial ATP signaling: what is its role in bladder sensation? Neurourol Urodyn 2016; 36:966-972. [PMID: 27542121 DOI: 10.1002/nau.23099] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/29/2016] [Indexed: 12/30/2022]
Abstract
AIM Bladder functional disorders are common health problems; however, their pathologies are poorly understood. Adenosine triphosphate (ATP) released from the urothelium has been suggested to have an essential role in the micturition reflex, and its involvement in bladder functional disorders has been intensively investigated. Here, we review the latest advances in research on urothelial ATP signaling. METHODS We reviewed research articles on the role of the urothelium and urothelial ATP release in bladder function. RESULTS Mice lacking purinergic receptors have been reported to exhibit marked bladder hyporeflexia. Based on this observation, it was commonly believed, according to the widely held ATP urothelial signaling theory, that stretch-induced urothelial ATP release mediates the sensation of bladder filling via purinergic receptors. However, recent studies employing novel experimental methods and approaches have demonstrated that there are no significant differences in bladder function between wild-type and purinergic receptor knockout mice under physiological conditions. Nonetheless, under pathological conditions, inhibition of purinergic receptors has been shown to improve bladder hyperactivity. Moreover, enhanced urothelial ATP release has been reported in patients with bladder functional disorders. CONCLUSIONS Recently, conflicting evidence has led us to question the role of urothelial ATP signaling in normal micturition reflex. In contrast, under pathological conditions, it seems likely that enhanced urothelial ATP signaling mediates bladder hyperactivity. These recent findings suggest that the urothelial ATP signaling pathway is a potential therapeutic target for bladder functional disorders.
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Affiliation(s)
- Kentaro Takezawa
- Department of Urology, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Urology, Osaka General Medical Center, Osaka, Japan
| | - Makoto Kondo
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Norio Nonomura
- Department of Urology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Osaka University Graduate School of Medicine, Suita, Japan
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