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Aresta Branco MSL, Perrino BA, Mutafova-Yambolieva VN. Spatial mapping of ectonucleotidase gene expression in the murine urinary bladder. Front Physiol 2023; 14:1306500. [PMID: 38098806 PMCID: PMC10719621 DOI: 10.3389/fphys.2023.1306500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 11/16/2023] [Indexed: 12/17/2023] Open
Abstract
Purinergic signaling is important for normal bladder function, as it is thought to initiate the voiding reflex and modulate smooth muscle tone. The availability of adenine nucleotides and nucleosides (aka purines) at receptor sites of various cell types in the bladder wall is regulated by ectonucleotidases (ENTDs). ENTDs hydrolyze purines such as adenosine 5'-triphosphate (ATP) and adenosine 5'-diphosphate (ADP) with varying preference for the individual substrate. Therefore, the end effect of extracellular purines may depend significantly on the type of ENTD that is expressed in close proximity to the target cells. ENTDs likely have distinct cellular associations, but the specific locations of individual enzymes in the bladder wall are poorly understood. We used RNAscope™, an RNA in situ hybridization (ISH) technology, to visualize the distribution and measure the levels of gene expression of the main recognized ectonucleotidases in large high-resolution images of murine bladder sections. The relative gene expression of ENTDs was Entpd3 > Alpl >> Enpp1 = Entpd2 >> Enpp3 > Entpd1 (very low to no signal) in the urothelium, Entpd1 ≥ Entpd2 >> Enpp3 > Enpp1 = Alpl ≥ Nt5e (very low to no signal) in the lamina propria, and Entpd1 >> Nt5e = Entpd2 >> Enpp1 > Alpl = Enpp3 in the detrusor. These layer-specific differences might be important in compartmentalized regulation of purine availability and subsequent functions in the bladder wall and may explain reported asymmetries in purine availability in the bladder lumen and suburothelium/lamina propria spaces.
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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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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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Mechanosensitivity Is a Characteristic Feature of Cultured Suburothelial Interstitial Cells of the Human Bladder. Int J Mol Sci 2020; 21:ijms21155474. [PMID: 32751838 PMCID: PMC7432121 DOI: 10.3390/ijms21155474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/24/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022] Open
Abstract
Bladder dysfunction is characterized by urgency, frequency (pollakisuria, nocturia), and dysuria and may lead to urinary incontinence. Most of these symptoms can be attributed to disturbed bladder sensitivity. There is growing evidence that, besides the urothelium, suburothelial interstitial cells (suICs) are involved in bladder afferent signal processing. The massive expansion of the bladder during the filling phase implicates mechanical stress delivered to the whole bladder wall. Little is known about the reaction of suICs upon mechanical stress. Therefore, we investigated the effects of mechanical stimulation in cultured human suICs. We used fura-2 calcium imaging as a major physiological readout. We found spontaneous intracellular calcium activity in 75 % of the cultured suICs. Defined local pressure application via a glass micropipette led to local increased calcium activity in all stimulated suICs, spreading over the whole cell. A total of 51% of the neighboring cells in a radius of up to 100 µm from the stimulated cell showed an increased activity. Hypotonic ringer and shear stress also induced calcium transients. We found an 18-times increase in syncytial activity compared to unstimulated controls, resulting in an amplification of the primary calcium signal elicited in single cells by 50%. Our results speak in favor of a high sensitivity of suICs for mechanical stress and support the view of a functional syncytium between suICs, which can amplify and distribute local stimuli. Previous studies of connexin expression in the human bladder suggest that this mechanism could also be relevant in normal and pathological function of the bladder in vivo.
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Modulation of lower urinary tract smooth muscle contraction and relaxation by the urothelium. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2018; 391:675-694. [DOI: 10.1007/s00210-018-1510-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/08/2018] [Indexed: 10/14/2022]
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Heppner TJ, Hennig GW, Nelson MT, Vizzard MA. Rhythmic Calcium Events in the Lamina Propria Network of the Urinary Bladder of Rat Pups. Front Syst Neurosci 2017; 11:87. [PMID: 29321730 PMCID: PMC5732214 DOI: 10.3389/fnsys.2017.00087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/14/2017] [Indexed: 01/23/2023] Open
Abstract
The lamina propria contains a dense network of cells, including interstitial cells (ICs), that may play a role in bladder function by modulating communication between urothelium, nerve fibers and smooth muscle or acting as pacemakers. Transient receptor potential vanilloid 4 (TRPV4) channels allow cation influx and may be involved in sensing stretch or chemical irritation in urinary bladder. Urothelium was removed from rats (P0-Adult), cut into strips, and loaded with a Ca2+ fluorescent dye (Fluo-2 AM leak resistant or Cal 520) for 90 min (35-37°C) to measure Ca2+ events. Ca2+ events were recorded for a period of 60 seconds (s) in control and after drug treatment. A heterogeneous network of cells was identified at the interface of the urothelium and lamina propria of postnatal rat pups, aged ≤ postnatal (P) day 21, with diverse morphology (round, fusiform, stellate with numerous projections) and expressing platelet-derived growth factor receptor alpha (PDGFRα)- and TRPV4-immunoreactivity (IR). Ca2+ transients occurred at a slow frequency with an average interval of 30 ± 8.6 s. Waveform analyses of Ca2+ transients in cells in the lamina propria network revealed long duration Ca2+ events with slow upstrokes. We observed slow propagating waves of activity in the lamina propria network that displayed varying degrees of coupling. Application of the TRPV4 agonist, GSK1016790 (100 nM), increased the duration of Ca2+ events, the number of cells with Ca2+ events and the integrated Ca2+ activity corresponding to propagation of activity among cells in the lamina propria network. However, GSK2193874 (1 μM), a potent antagonist of TRPV4 channels, was without effect. ATP (1 μM) perfusion increased the number of cells in the lamina propria exhibiting Ca2+ events and produced tightly coupled network activity. These findings indicate that ATP and TRPV4 can activate cells in the laminar propria network, leading to the appearance of organized propagating wavefronts.
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Affiliation(s)
- Thomas J Heppner
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Grant W Hennig
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Mark T Nelson
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Margaret A Vizzard
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
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Cho KJ, Koh JS, Choi J, Kim JC. Changes in Adenosine Triphosphate and Nitric Oxide in the Urothelium of Patients with Benign Prostatic Hyperplasia and Detrusor Underactivity. J Urol 2017; 198:1392-1396. [PMID: 28655527 DOI: 10.1016/j.juro.2017.06.080] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2017] [Indexed: 11/19/2022]
Abstract
PURPOSE We investigated changes in the levels of adenosine triphosphate and nitric oxide in the urothelium of men with detrusor underactivity and benign prostatic hyperplasia. MATERIALS AND METHODS We prospectively enrolled in study 30 men who planned to undergo surgical treatment for benign prostatic hyperplasia. The 15 patients with a bladder contractility index less than 100 were assigned to the detrusor underactivity group while the 15 with a bladder contractility index more than 100 were assigned to the no detrusor underactivity group. Bladder mucosal specimens were collected at surgical prostate resection, and adenosine triphosphate and endothelial nitric oxide synthase were analyzed in these specimens. The levels of adenosine triphosphate and endothelial nitric oxide synthase were compared between the 2 groups. The correlation of urodynamic parameters with adenosine triphosphate and endothelial nitric oxide synthase was assessed in all patients. RESULTS Mean ± SEM endothelial nitric oxide synthase did not significantly differ between the detrusor underactivity and no underactivity groups (3.393 ± 0.969 vs 1.941 ± 0.377 IU/ml, p = 0.247). However, the mean level of adenosine triphosphate in the detrusor underactivity group was significantly lower than in the no detrusor underactivity group (1.289 ± 0.320 vs 9.262 ± 3.285 pmol, p = 0.011). In addition, in all patients adenosine triphosphate positively correlated with the bladder contractility index (r = 0.478, p = 0.018) and with detrusor pressure on maximal flow (r = 0.411, p = 0.046). CONCLUSIONS Adenosine triphosphate was significantly decreased in the urothelium in men with detrusor underactivity and benign prostatic hyperplasia, reflecting the change in detrusor function.
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Affiliation(s)
- Kang Jun Cho
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea
| | - Jun Sung Koh
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea
| | - Jinbong Choi
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea
| | - Joon Chul Kim
- Department of Urology, Bucheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, Korea.
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Neuhaus J, Schröppel B, Dass M, Zimmermann H, Wolburg H, Fallier‐Becker P, Gevaert T, Burkhardt CJ, Do HM, Stolzenburg J. 3D‐electron microscopic characterization of interstitial cells in the human bladder upper lamina propria. Neurourol Urodyn 2017; 37:89-98. [DOI: 10.1002/nau.23270] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/14/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Jochen Neuhaus
- Department of UrologyResearch Laboratory, University LeipzigLeipzigGermany
| | - Birgit Schröppel
- Natural and Medical Sciences Institute (NMI) at the University of TuebingenReutlingenGermany
| | - Martin Dass
- Carl Zeiss Microscopy GmbH, TrainingApplication and Support Center (TASC) Application Support EMMunichGermany
| | - Hans Zimmermann
- Carl Zeiss Microscopy GmbH, TrainingApplication and Support Center (TASC) Application Support EMMunichGermany
| | - Hartwig Wolburg
- Institute of Pathology and NeuropathologyUniversity Hospital TuebingenTuebingenGermany
| | - Petra Fallier‐Becker
- Institute of Pathology and NeuropathologyUniversity Hospital TuebingenTuebingenGermany
| | - Thomas Gevaert
- Department of Development and RegenerationKU Leuven, Laboratory of Experimental UrologyLeuvenBelgium
| | - Claus J. Burkhardt
- Natural and Medical Sciences Institute (NMI) at the University of TuebingenReutlingenGermany
| | - Hoang Minh Do
- Department of UrologyUniversity Leipzig, University Hospital LeipzigLeipzigGermany
| | - Jens‐Uwe Stolzenburg
- Department of UrologyUniversity Leipzig, University Hospital LeipzigLeipzigGermany
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Host Responses to Urinary Tract Infections and Emerging Therapeutics: Sensation and Pain within the Urinary Tract. Microbiol Spectr 2016; 4. [DOI: 10.1128/microbiolspec.uti-0023-2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
ABSTRACT
Urinary tract infection (UTI) pathogenesis is understood increasingly at the level of the uropathogens and the cellular and molecular mediators of host inflammatory responses. However, little is known about the mediators of symptoms during UTI and what distinguishes symptomatic events from asymptomatic bacteriuria. Here, we review bladder physiology and sensory pathways in the context of an emerging literature from murine models dissecting the host and pathogen factors mediating pain responses during UTI. The bladder urothelium is considered a mediator of sensory responses and appears to play a role in UTI pain responses. Virulence factors of uropathogens induce urothelial damage that could trigger pain due to compromised bladder-barrier function. Instead, bacterial glycolipids are the major determinants of UTI pain independent of urothelial damage, and the O-antigen of lipopolysaccharide modulates pain responses. The extent of pain modulation by O-antigen can have profound effects, from abolishing pain responses to inducing chronic pain that results in central nervous system features reminiscent of neuropathic pain. Although these effects are largely dependent upon Toll-like receptors, pain is independent of inflammation. Surprisingly, some bacteria even possess analgesic properties, suggesting that bacteria exhibit a wide range of pain phenotypes in the bladder. In summary, UTI pain is a complex form of visceral pain that has significant potential to inform our understanding of bacterial pathogenesis and raises the specter of chronic pain resulting from transient infection, as well as novel approaches to treating pain.
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Sugaya K, Nishijima S, Kadekawa K, Ashitomi K, Ueda T, Yamamoto H. Naftopidil improves locomotor activity and urinary frequency in rats with pelvic venous congestion. Biomed Res 2016; 37:221-6. [PMID: 27544997 DOI: 10.2220/biomedres.37.221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The α1D/A receptor antagonist, naftopidil, inhibits micturition reflex by acting on various different sites. We examined the effects of naftopidil on bladder activity and changes in the induced urinary frequency using female rats with pelvic venous congestion (PC). Twenty-four female rats were divided into sham, PC, and PC/naftopidil groups. After anesthetizing rats in the PC and PC/naftopidil groups, the bilateral common iliac veins and uterine veins were ligated. Rats in the sham and PC groups were fed a standard diet, while rats in the PC/naftopidil group were fed diets containing 0.04% naftopidil. After 4 weeks of treatment, locomotor activity, urinary nitric oxide metabolites (NOx), continuous cystometry, and plasma monoamine measurements were performed. PC rats exhibited a decrease of locomotor activity, a shorter interval between bladder contractions on continuous cystometry, and decreased urinary NOx and plasma serotonin levels than the sham rats. The PC/naftopidil rats exhibited an increase of locomotor activity, a longer interval between bladder contractions, and increased urinary NOx and plasma serotonin levels. Therefore, naftopidil might improve bladder dysfunction induced by pelvic venous congestion due to several actions in the central nervous system and bladder tissue, as well as acting as an α1 blocker to cause pelvic venous dilation.
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Sugaya K, Nishijima S, Kadekawa K, Ashitomi K, Ueda T, Yamamoto H. Effects of silodosin on bladder activity in rats with frequent urination induced by pelvic venous congestion. Int J Urol 2016; 23:881-887. [DOI: 10.1111/iju.13158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/05/2016] [Indexed: 11/27/2022]
Affiliation(s)
| | | | | | | | - Tomoyuki Ueda
- Faculty of Medicine; The Institute for Animal Experiments; University of the Ryukyus; Okinawa Japan
| | - Hideyuki Yamamoto
- Department of Biochemistry; Graduate School of Medicine; University of the Ryukyus; Okinawa Japan
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Svennersten K, Hallén-Grufman K, de Verdier PJ, Wiklund NP, Poljakovic M. Localization of P2X receptor subtypes 2, 3 and 7 in human urinary bladder. BMC Urol 2015; 15:81. [PMID: 26253104 PMCID: PMC4529706 DOI: 10.1186/s12894-015-0075-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/28/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Voiding dysfunctions are a common problem that has a severe negative impact on the quality of life. Today there is a need for new drug targets for these conditions. The role of ATP receptors in bladder physiology has been studied for some time, primarily in animal models. The aim of this work is to investigate the localization of the ATP receptors P2X2, P2X3 and P2X7 and their colocalization with vimentin and actin in the human urinary bladder. METHODS Immunohistochemical analysis was conducted on full-thickness bladder tissues from fundus and trigonum collected from 15 patients undergoing open radical cystectomy due to chronic cystitis, bladder cancer or locally advanced prostate cancer. Colocalization analyses were performed between the three different P2X subtypes and the structural proteins vimentin and actin. Specimens were examined using epifluorescence microscopy and correlation coefficients were calculated for each costaining as well as the mean distance from the laminin positive basal side of the urothelium to the vimentin positive cells located in the suburothelium. RESULTS P2X2 was expressed in vimentin positive cells located in the suburothelium. Less distinct labelling of P2X2 was also observed in actin positive smooth muscle cells and in the urothelium. P2X3 was expressed in vimentin positive cells surrounding the smooth muscle, and in vimentin positive cells located in the suburothelium. Weaker P2X3 labelling was seen in the urothelium. P2X7 was expressed in the smooth muscle cells and the urothelium. In the suburothelium, cells double positive for P2X2 and vimentin where located closer to the urothelium while cells double positive for P2X3 and vimentin where located further from the urothelium. CONCLUSION The results from this study demonstrate that there is a significant difference in the expression of the purinergic P2X2, P2X3 and P2X7 receptors in the different histological layers of the human urinary bladder.
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Affiliation(s)
- Karl Svennersten
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, 171 76, Stockholm, Sweden.
- Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
| | - Katarina Hallén-Grufman
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, 171 76, Stockholm, Sweden.
- Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
| | - Petra J de Verdier
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - N Peter Wiklund
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, 171 76, Stockholm, Sweden.
- Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
| | - Mirjana Poljakovic
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, 171 76, Stockholm, Sweden.
- Department of Urology, Karolinska University Hospital, Stockholm, Sweden.
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Abstract
It is well established that in most species, exocytotic vesicular release of ATP from parasympathetic neurons contributes to contraction of the bladder. However, ATP is released not only from parasympathetic nerves, but also from the urothelium. During bladder filling, the urothelium is stretched and ATP is released from the umbrella cells thereby activating mechanotransduction pathways. ATP release can also be induced by various mediators present in the urine and and/or released from nerves or other components of the lamina propria. Urothelial release of ATP is mainly attributable to vesicular transport or exocytosis and, to a smaller extent, to pannexin hemichannel conductive efflux. After release, ATP acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex and to mediate the sensation of bladder filling and urgency. ATP also acts on suburothelial interstitial cells/myofibroblasts generating an inward Ca(2+) transient that via gap junctions could provide a mechanism for long-distance spread of signals from the urothelium to the detrusor muscle. ATP release can be affected by urological diseases, e.g., interstitial cystitis and both the mechanisms of release and the receptors activated by ATP may be targets for future drugs for treatment of lower urinary tract disorders.
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Ford AP, Undem BJ, Birder LA, Grundy D, Pijacka W, Paton JFR. P2X3 receptors and sensitization of autonomic reflexes. Auton Neurosci 2015; 191:16-24. [PMID: 25956567 DOI: 10.1016/j.autneu.2015.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A great deal of basic and applied physiology and pharmacology in sensory and autonomic neuroscience has teased apart mechanisms that drive normal perception of mechanical, thermal and chemical signals and convey them to CNS, the distinction of fiber types and receptors and channels that mediate them, and how they may become dysfunctional or maladaptive in disease. Likewise, regulation of efferent autonomic traffic to control organ reflexes has been well studied. In both afferent and efferent limbs, a wide array of potential therapeutic mechanisms has surfaced, some of which have progressed into clinic, if not full regrastration. One conversation that has been less well progressed relates to how the afferent limb and its sensitization shapes the efferent outputs, and where modulation may offer new therapeutic avenues, especially for poorly addressed and common signs and symptoms of disease. Therapeutics for CV disease (HF, hypertension), respiratory disease (asthma, COPD), urological disease (OAB), GI disease (IBS), and inter alia, have largely focused on the efferent control of effector cells to modulate movement, contraction and secretion; medicinal needs remain with limits to efficacy, AEs and treatment resistance being common. We now must turn, in the quest for improved therapeutics, to understand how sensation from these organs becomes maladapted and sensitized in disease, and what opportunities may arise for improved therapeutics given the abundance of targets, many pharmacologically untapped, on the afferent side. One might look at the treatment resistant hypertension and the emerging benefit of renal denervation; or urinary bladder overactivity / neurogenic bladder and the emergence of neuromodulation, capsaicin instillation or botox injections to attenuate sensitized reflexes, as examples of merely the start of such progress. This review examines this topic more deeply, as applies to four major organ systems all sharing a great need from unsatisfied patients.
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Affiliation(s)
| | - Bradley J Undem
- Johns Hopkins School of Medicine, Division of Allergy and Clinical Immunology, Baltimore, MD 21224, USA
| | - Lori A Birder
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburg, PA 15261, USA
| | - David Grundy
- Department of Biomedical Science, The University of Sheffield, Sheffield S10 2TN, UK
| | - Wioletta Pijacka
- School of Physiology & Pharmacology, Bristol CardioVascular, University of Bristol, Bristol, BS8 1TD, UK
| | - Julian F R Paton
- School of Physiology & Pharmacology, Bristol CardioVascular, University of Bristol, Bristol, BS8 1TD, UK
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15
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Rusu MC, Folescu R, Mănoiu VS, Didilescu AC. Suburothelial interstitial cells. Cells Tissues Organs 2014; 199:59-72. [PMID: 24801000 DOI: 10.1159/000360816] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 11/19/2022] Open
Abstract
The suburothelium has received renewed interest because of its role in sensing bladder fullness. Various studies evaluated suburothelial myofibroblasts (MFs), interstitial cells (ICs), interstitial Cajal cells (ICCs) or telocytes (TCs), which resulted in inconsistencies in terminology and difficulties in understanding the suburothelial structure. In order to elucidate these issues, the use of electron microscopy seems to be an ideal choice. It was hypothesized that the cell population of the suburothelial band is heterogeneous in an attempt to clarify the above-mentioned inconsistencies. The suburothelial ICs of the bladder were evaluated by immunohistochemistry (IHC) and transmission electron microscopy (TEM). Bladder samples from 6 Wistar rats were used for IHC and TEM studies and human bladder autopsy samples were used for IHC. Desmin labeled only the detrusor muscle, while all the myoid structures of the bladder wall were positive for α-smooth muscle actin (SMA). A distinctive α-SMA-positive suburothelial layer was identified. A layered structure of the immediate suburothelial band was detected using TEM: (1) the inner suburothelial layer consisted of fibroblasts equipped for matrix synthesis; (2) the middle suburothelial layer consisted of smooth muscle cells (SMCs) and myoid ICCs, and (3) the outer suburothelial layer consisted of ICs with TC morphology, building a distinctive network. In conclusion, the suburothelial layer consists of distinctive types of ICs but not MFs. The myoid layer, with SMCs and ICCs, which could be considered identical to the α-SMA-positive cells in the suburothelial band, seems the best-equipped layer for pacemaking and signaling. Noteworthy, the network of ICs also seems suitable for stromal signaling.
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16
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Burnstock G. Purinergic signalling in the urinary tract in health and disease. Purinergic Signal 2014; 10:103-55. [PMID: 24265069 PMCID: PMC3944045 DOI: 10.1007/s11302-013-9395-y] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 12/25/2022] Open
Abstract
Purinergic signalling is involved in a number of physiological and pathophysiological activities in the lower urinary tract. In the bladder of laboratory animals there is parasympathetic excitatory cotransmission with the purinergic and cholinergic components being approximately equal, acting via P2X1 and muscarinic receptors, respectively. Purinergic mechanosensory transduction occurs where ATP, released from urothelial cells during distension of bladder and ureter, acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex, via low threshold fibres, and nociception, via high threshold fibres. In human bladder the purinergic component of parasympathetic cotransmission is less than 3 %, but in pathological conditions, such as interstitial cystitis, obstructed and neuropathic bladder, the purinergic component is increased to 40 %. Other pathological conditions of the bladder have been shown to involve purinoceptor-mediated activities, including multiple sclerosis, ischaemia, diabetes, cancer and bacterial infections. In the ureter, P2X7 receptors have been implicated in inflammation and fibrosis. Purinergic therapeutic strategies are being explored that hopefully will be developed and bring benefit and relief to many patients with urinary tract disorders.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Abstract
The urothelium, which lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, not only forms a high-resistance barrier to ion, solute and water flux, and pathogens, but also functions as an integral part of a sensory web which receives, amplifies, and transmits information about its external milieu. Urothelial cells have the ability to sense changes in their extracellular environment, and respond to chemical, mechanical and thermal stimuli by releasing various factors such as ATP, nitric oxide, and acetylcholine. They express a variety of receptors and ion channels, including P2X3 purinergic receptors, nicotinic and muscarinic receptors, and TRP channels, which all have been implicated in urothelial-neuronal interactions, and involved in signals that via components in the underlying lamina propria, such as interstitial cells, can be amplified and conveyed to nerves, detrusor muscle cells, and ultimately the central nervous system. The specialized anatomy of the urothelium and underlying structures, and the possible communication mechanisms from urothelial cells to various cell types within the bladder wall are described. Changes in the urothelium/lamina propria ("mucosa") produced by different bladder disorders are discussed, as well as the mucosa as a target for therapeutic interventions.
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Affiliation(s)
- Lori Birder
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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Neuhaus J, Schwalenberg T. Intravesical treatments of bladder pain syndrome/interstitial cystitis. Nat Rev Urol 2012. [DOI: 10.1038/nrurol.2012.217] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Cheng Y, Mansfield KJ, Allen W, Millard RJ, Burcher E, Moore KH. Correlation between cystometric volumes, ATP release, and pH in women with overactive bladder versus controls. Neurourol Urodyn 2012; 32:969-73. [PMID: 23129360 DOI: 10.1002/nau.22344] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 10/01/2012] [Indexed: 12/12/2022]
Abstract
AIMS In the bladder, ATP is an important signaling molecule, which is released by bladder stretch and acid. We hypothesized that ATP might play a unique role in patients with OAB, characterized by low bladder volumes at first desire to void (FDV) and maximal cystometric capacity (MCC) and symptoms of frequency/urgency [mild bladder pain syndrome (BPS)]. Our aim was to investigate the correlation between ATP release and urodynamic parameters, as well as urine pH, in OAB patients. METHODS Routine cystometry was performed in a consecutive series of 249 women. The voided urodynamic fluid (VUF) was stored at -20°C and ATP measured using bioluminescence. Catheter urine was collected for pH measurement. Correlations between two factors were tested by linear regression analysis. RESULTS Subjects with urinary tract infection, voiding dysfunction, and detrusor overactivity (DO) were excluded. For OAB patients (n = 25), there was an inverse correlation between ATP concentration in VUF and FDV (r(2) = 0.25; P = 0.01) but not MCC. This was not seen in controls (n = 69). In OAB, but not controls, there was a significant reverse correlation (r(2) = 0.16; P = 0.047) between ATP in VUF and urine pH. Urine pH was not significantly correlated with MCC in either group. CONCLUSIONS In OAB patients, ATP is an important factor for initial perception of need to urinate (as indicated by FDV). This is similar to our previous findings in patients with DO, suggesting that ATP may mediate initial afferent sensation in patients with bladder dysfunctions characterized by urgency. ATP release was also strongly affected by urine pH, in patients with OAB (at FDV).
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Affiliation(s)
- Ying Cheng
- Department of Urogynaecology, St George Hospital, University of New South Wales, Sydney, North South Wales, Australia.
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Li Y, Xue L, Miao Q, Mao F, Yao L, Yuan J, Qin W, Zhao Y, Sun H, Liu F, Wang H. Expression and electrophysiological characteristics of P2X3receptors in interstitial cells of Cajal in rats with partial bladder outlet obstruction. BJU Int 2012; 111:843-51. [PMID: 22882254 DOI: 10.1111/j.1464-410x.2012.11408.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuxin Li
- Department of Urology; Xijing Hospital; Xi'an; China
| | - Li Xue
- Department of Urology; Xijing Hospital; Xi'an; China
| | - Qing Miao
- Institute of Meteria Medical; The Fourth Military Medical University; Xi'an; China
| | - Fengfeng Mao
- Laboratory Animal Centre; The Fourth Military Medical University; Xi'an; China
| | - Liping Yao
- State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases; The Fourth Military Medical University; Xi'an; China
| | - Jianlin Yuan
- Department of Urology; Xijing Hospital; Xi'an; China
| | - Weijun Qin
- Department of Urology; Xijing Hospital; Xi'an; China
| | - Yufeng Zhao
- Department of Experimental Basic Medicine; The Fourth Military Medical University; Xi'an; China
| | - Hang Sun
- Department of Urology; Xijing Hospital; Xi'an; China
| | - Fei Liu
- Department of Urology; Xijing Hospital; Xi'an; China
| | - He Wang
- Department of Urology; Xijing Hospital; Xi'an; China
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