1
|
Jones BM, Mingin GC, Tykocki NR. The mast cell stimulator compound 48/80 causes urothelium-dependent increases in murine urinary bladder contractility. Am J Physiol Renal Physiol 2023; 325:F50-F60. [PMID: 37199916 PMCID: PMC10292985 DOI: 10.1152/ajprenal.00116.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 05/19/2023] Open
Abstract
Mast cells and degranulation of preformed inflammatory mediators contribute to lower urinary tract symptoms. This study investigated pathways by which the mast cell stimulator compound 48/80 alters urinary bladder smooth muscle contractility via mast cell activation. We hypothesized that 1) mast cell degranulation causes spontaneous urinary bladder smooth muscle contractions and 2) these contractions are caused by urothelium-derived PGE2. Urothelium-intact and -denuded urinary bladder strips were collected from mast cell-sufficient (C57Bl/6) and mast cell-deficient (B6.Cg-Kitw-sh) mice to determine if compound 48/80 altered urinary bladder smooth muscle (UBSM) contractility. Electrical field stimulation was used to assess the effects of compound 48/80 on nerve-evoked contractions. Antagonists/inhibitors were used to identify prostanoid signaling pathways activated or if direct activation of nerves was involved. Compound 48/80 caused slow-developing contractions, increased phasic activity, and augmented nerve-evoked responses in both mast cell-sufficient and -deficient mice. Nerve blockade had no effect on these responses; however, they were eliminated by removing the urothelium. Blockade of P2 purinoreceptors, cyclooxygenases, or G protein signaling abolished compound 48/80 responses. However, only combined blockade of PGE2 (EP1), PGF2α (FP), and thromboxane A2 (TP) receptors inhibited compound 48/80-induced responses. Thus, the effects of compound 48/80 are urothelium dependent but independent of mast cells. Furthermore, these effects are mediated by druggable inflammatory pathways that may be used to manage inflammatory nonneurogenic bladder hyperactivity. Finally, these data strongly suggest that great care must be taken when using compound 48/80 to determine mast cell-dependent responses in the urinary bladder.NEW & NOTEWORTHY Urothelial cells are first responders to noxious contents of the urine. Our study demonstrates that the urothelium is not only a barrier but also a modulator of urinary bladder smooth muscle phasic activity and contractility independent of immune cell recruitment in response to an inflammatory insult.
Collapse
Affiliation(s)
- B Malique Jones
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, United States
| | - Gerald C Mingin
- Larner College of Medicine, University of Vermont, Burlington, Vermont, United States
| | - Nathan R Tykocki
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, United States
| |
Collapse
|
2
|
Aresta Branco MSL, Gutierrez Cruz A, Peri LE, Mutafova-Yambolieva VN. The Pannexin 1 Channel and the P2X7 Receptor Are in Complex Interplay to Regulate the Release of Soluble Ectonucleotidases in the Murine Bladder Lamina Propria. Int J Mol Sci 2023; 24:9964. [PMID: 37373111 PMCID: PMC10298213 DOI: 10.3390/ijms24129964] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/25/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
The bladder urothelium releases ATP into the lamina propria (LP) during filling, which can activate P2X receptors on afferent neurons and trigger the micturition reflex. Effective ATP concentrations are largely dependent on metabolism by membrane-bound and soluble ectonucleotidases (s-ENTDs), and the latter are released in the LP in a mechanosensitive manner. Pannexin 1 (PANX1) channel and P2X7 receptor (P2X7R) participate in urothelial ATP release and are physically and functionally coupled, hence we investigated whether they modulate s-ENTDs release. Using ultrasensitive HPLC-FLD, we evaluated the degradation of 1,N6-etheno-ATP (eATP, substrate) to eADP, eAMP, and e-adenosine (e-ADO) in extraluminal solutions that were in contact with the LP of mouse detrusor-free bladders during filling prior to substrate addition, as an indirect measure of s-ENDTS release. Deletion of Panx1 increased the distention-induced, but not the spontaneous, release of s-ENTDs, whereas activation of P2X7R by BzATP or high concentration of ATP in WT bladders increased both. In Panx1-/- bladders or WT bladders treated with the PANX1 inhibitory peptide 10Panx, however, BzATP had no effect on s-ENTDS release, suggesting that P2X7R activity depends on PANX1 channel opening. We concluded, therefore, that P2X7R and PANX1 are in complex interaction to regulate s-ENTDs release and maintain suitable ATP concentrations in the LP. Thus, while stretch-activated PANX1 hinders s-ENTDS release possibly to preserve effective ATP concentration at the end of bladder filling, P2X7R activation, presumably in cystitis, would facilitate s-ENTDs-mediated ATP degradation to counteract excessive bladder excitability.
Collapse
Affiliation(s)
| | | | | | - Violeta N. Mutafova-Yambolieva
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada Reno, Reno, NV 89557, USA; (M.S.L.A.B.); (A.G.C.); (L.E.P.)
| |
Collapse
|
3
|
Aresta Branco MSL, Gutierrez Cruz A, Borhani Peikani M, Mutafova-Yambolieva VN. Sensory Neurons, PIEZO Channels and PAC1 Receptors Regulate the Mechanosensitive Release of Soluble Ectonucleotidases in the Murine Urinary Bladder Lamina Propria. Int J Mol Sci 2023; 24:ijms24087322. [PMID: 37108490 PMCID: PMC10138949 DOI: 10.3390/ijms24087322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
The urinary bladder requires adequate concentrations of extracellular adenosine 5'-triphosphate (ATP) and other purines at receptor sites to function properly. Sequential dephosphorylation of ATP to ADP, AMP and adenosine (ADO) by membrane-bound and soluble ectonucleotidases (s-ENTDs) is essential for achieving suitable extracellular levels of purine mediators. S-ENTDs, in particular, are released in the bladder suburothelium/lamina propria (LP) in a mechanosensitive manner. Using 1,N6-etheno-ATP (eATP) as substrate and sensitive HPLC-FLD methodology, we evaluated the degradation of eATP to eADP, eAMP and eADO in solutions that were in contact with the LP of ex vivo mouse detrusor-free bladders during filling prior to substrate addition. The inhibition of neural activity with tetrodotoxin and ω-conotoxin GVIA, of PIEZO channels with GsMTx4 and D-GsMTx4 and of the pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1) with PACAP6-38 all increased the distention-induced but not spontaneous release of s-ENTDs in LP. It is conceivable, therefore, that the activation of these mechanisms in response to distention restricts the further release of s-ENTDs and prevents excessive hydrolysis of ATP. Together, these data suggest that afferent neurons, PIEZO channels, PAC1 receptors and s-ENTDs form a system that operates a highly regulated homeostatic mechanism to maintain proper extracellular purine concentrations in the LP and ensure normal bladder excitability during bladder filling.
Collapse
Affiliation(s)
- Mafalda S L Aresta Branco
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Alejandro Gutierrez Cruz
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Mahsa Borhani Peikani
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | | |
Collapse
|
4
|
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.
Collapse
|
5
|
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.
Collapse
|
6
|
Chen Y, Ji P, Ma G, Song Z, Tang BQ, Li T. Simultaneous determination of cellular adenosine nucleotides, malondialdehyde, and uric acid using HPLC. Biomed Chromatogr 2021; 35:e5156. [PMID: 33955024 DOI: 10.1002/bmc.5156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/24/2021] [Accepted: 04/30/2021] [Indexed: 11/10/2022]
Abstract
Adenine nucleotides and malondialdehyde (MDA) are key components involved in energy metabolism and reactive oxygen species (ROS) production. Measuring the levels of these components at the same time would be critical in studying mitochondrial functions. We have established a HPLC method to simultaneously measure adenosine triphosphate, adenosine diphosphate, adenosine monophosphate, MDA, and uric acid (UA). The samples were treated with perchloric acid followed by centrifugation. After neutralization, the supernatant was subjected to HPLC determination. HPLC was performed using a C18 chromatographic column, isocratic elusion, and UV detection. The detection and quantification limits for these components were determined with standard solutions. The precision, repeatability, and 24-h stability were evaluated using cellular samples, and their relative standard deviations were all within 2%. The reproducibility and efficiency were confirmed with sample recovery tests and the observed oxidative effects of H2 O2 on Jurkat cells. With this method, we discovered the dependence of energy and oxidative states on the density of Jurkat cells cultured in suspension. We also found a significant correlation between UA in serum and that in saliva. These results indicate that this method has good accuracy and applicability. It can be used in biological, pharmacological, and clinical studies, especially those involving mitochondria, ROS, and purinergic signaling.
Collapse
Affiliation(s)
- Yanjie Chen
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| | - Peng Ji
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| | - Guangyin Ma
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| | - Zehua Song
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| | - Bruce Qing Tang
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| | - Tongju Li
- Ennova Institute of Life Science and Technology, ENN Group, Langfang, China
| |
Collapse
|
7
|
Vanneste M, Segal A, Voets T, Everaerts W. Transient receptor potential channels in sensory mechanisms of the lower urinary tract. Nat Rev Urol 2021; 18:139-159. [PMID: 33536636 DOI: 10.1038/s41585-021-00428-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2021] [Indexed: 01/30/2023]
Abstract
Disruptions to sensory pathways in the lower urinary tract commonly occur and can give rise to lower urinary tract symptoms (LUTS). The unmet clinical need for treatment of LUTS has stimulated research into the molecular mechanisms that underlie neuronal control of the bladder and transient receptor potential (TRP) channels have emerged as key regulators of the sensory processes that regulate bladder function. TRP channels function as molecular sensors in urothelial cells and afferent nerve fibres and can be considered the origin of bladder sensations. TRP channels in the lower urinary tract contribute to the generation of normal and abnormal bladder sensations through a variety of mechanisms, and have demonstrated potential as targets for the treatment of LUTS in functional disorders of the lower urinary tract.
Collapse
Affiliation(s)
- Matthias Vanneste
- Laboratory of Ion Channel Research, VIB Center for Brain & Disease Research, Leuven, and Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Andrei Segal
- Laboratory of Ion Channel Research, VIB Center for Brain & Disease Research, Leuven, and Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research, VIB Center for Brain & Disease Research, Leuven, and Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Wouter Everaerts
- Laboratory of Experimental Urology, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.
| |
Collapse
|
8
|
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: 73] [Impact Index Per Article: 18.3] [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.
Collapse
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
| |
Collapse
|
9
|
Hashitani H, Mitsui R, Lang R. Functional heterogeneity of PDGFRα (+) cells in spontaneously active urogenital tissues. Neurourol Urodyn 2020; 39:1667-1678. [PMID: 32531084 DOI: 10.1002/nau.24431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 11/06/2022]
Abstract
AIMS As PDGFRα (+) cells appear not to suppress the excitability of detrusor smooth muscle by generating SK3-dependent hyperpolarising as proposed in the gastrointestinal tract, we further explored the functional roles of PDGFRα (+) cells in regulating the spontaneous activity of urogenital tissues. METHODS Using PDGFRα-eGFP mice, intracellular Ca2+ signaling in PDGFRα (+) cells of the bladder lamina propria, renal pelvis, and seminal vesicle were visualized using Cal-590 fluorescence. The distribution and SK3 expression of PDGFRα (+) cells were also examined by immunohistochemistry. RESULTS In the bladder lamina propria, SK3 (-) PDGFRα (+) cells exhibited spontaneous Ca2+ transients and responded to stimulation of P2Y1 purinoceptors with MRS2365 (100 nM) or adenosine diphosphate (ADP) (100 μM) by developing Ca2+ transients. In the proximal renal pelvis, PDGFRα (+) cells were distributed in the mucosal, muscular and serosal layers but did not express SK3 immunoreactivity. PDGFRα (+) cells in the musculature resembling atypical smooth muscle cells generated spontaneous Ca2+ transients that were partially suppressed upon P2Y1-stimulation, while vigorously responding to human angiotensin II (100 nM). In the seminal vesicle, PDGFRα (+) cells in the musculature but not mucosa expressed SK3 immunoreactivity. In the mucosa, the P2Y1 stimulation evoked Ca2+ transients in both PDGFRα (+) cells and PDGFRα (-) cells. CONCLUSION PDGFRα (+) cells in spontaneously active urogenital tissues display heterogeneity in terms of their SK3 expression and P2Y1-induced Ca2+ responses. Muscular PDGFRα (+) cells in the renal pelvis and mucosal PDGFRα (+) cells in the seminal vesicle may generate depolarizing signals to drive smooth muscle cells.
Collapse
Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Richard Lang
- Department of Physiology, Monash University, Clayton, Victoria, Australia
| |
Collapse
|
10
|
Durnin L, Kwok B, Kukadia P, McAvera R, Corrigan RD, Ward SM, Zhang Y, Chen Q, Koh SD, Sanders KM, Mutafova-Yambolieva VN. An ex vivo bladder model with detrusor smooth muscle removed to analyse biologically active mediators released from the suburothelium. J Physiol 2018; 597:1467-1485. [PMID: 30289177 DOI: 10.1113/jp276924] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Studies of urothelial cells, bladder sheets or lumens of filled bladders have suggested that mediators released from urothelium into suburothelium (SubU)/lamina propria (LP) activate mechanisms controlling detrusor excitability. None of these approaches, however, has enabled direct assessment of availability of mediators at SubU/LP during filling. We developed an ex vivo mouse bladder preparation with intact urothelium and SubU/LP but no detrusor, which allows direct access to the SubU/LP surface of urothelium during filling. Pressure-volume measurements during filling demonstrated that bladder compliance is governed primarily by the urothelium. Measurements of purine mediators in this preparation demonstrated asymmetrical availability of purines in lumen and SubU/LP, suggesting that interpretations based solely on intraluminal measurements of mediators may be inaccurate. The preparations are suitable for assessments of release, degradation and transport of mediators in SubU/LP during bladder filling, and are superior to experimental approaches previously used for urothelium research. ABSTRACT The purpose of this study was to develop a decentralized (ex vivo) detrusor smooth muscle (DSM)-denuded mouse bladder preparation, a novel model that enables studies on availability of urothelium-derived mediators at the luminal and anti-luminal aspects of the urothelium during filling. Urinary bladders were excised from C57BL6/J mice and the DSM was removed by fine-scissor dissection without touching the mucosa. Morphology and cell composition of the preparation wall, pressure-volume relationships during filling, and fluorescent dye permeability of control, protamine sulfate- and lipopolysaccharide-treated denuded bladders were characterized. The preparation wall contained intact urothelium and suburothelium (SubU)/lamina propria (LP) and lacked the DSM and the serosa. The utility of the model for physiological research was validated by measuring release, metabolism and transport of purine mediators at SubU/LP and in bladder lumen during filling. We determined asymmetrical availability of purines (e.g. ATP, ADP, AMP and adenosine) in lumen and at SubU/LP during filling, suggesting differential mechanisms of release, degradation and bilateral transurothelial transport of purines during filling. Some observations were validated in DSM-denuded bladder of the cynomolgus monkey (Macaca fascicularis). The novel model was superior to current models utilized to study properties of the urothelium (e.g. cultured urothelial cells, bladder mucosa sheets mounted in Ussing chambers or isolated bladder strips in organ baths) in that it enabled direct access to the vicinity of SubU/LP during authentic bladder filling. The model is particularly suitable for understanding local mechanisms of urothelium-DSM connectivity and for broad understanding of the role of urothelium in regulating continence and voiding.
Collapse
Affiliation(s)
- Leonie Durnin
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Benjamin Kwok
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Priya Kukadia
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Roisin McAvera
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Robert D Corrigan
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Sean M Ward
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qi Chen
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, 89557-0575, USA
| | | |
Collapse
|
11
|
Guan NN, Sharma N, Hallén-Grufman K, Jager EWH, Svennersten K. The role of ATP signalling in response to mechanical stimulation studied in T24 cells using new microphysiological tools. J Cell Mol Med 2018; 22:2319-2328. [PMID: 29392898 PMCID: PMC5867107 DOI: 10.1111/jcmm.13520] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 12/01/2017] [Indexed: 01/06/2023] Open
Abstract
The capacity to store urine and initiate voiding is a valued characteristic of the human urinary bladder. To maintain this feature, it is necessary that the bladder can sense when it is full and when it is time to void. The bladder has a specialized epithelium called urothelium that is believed to be important for its sensory function. It has been suggested that autocrine ATP signalling contributes to this sensory function of the urothelium. There is well‐established evidence that ATP is released via vesicular exocytosis as well as by pannexin hemichannels upon mechanical stimulation. However, there are still many details that need elucidation and therefore there is a need for the development of new tools to further explore this fascinating field. In this work, we use new microphysiological systems to study mechanostimulation at a cellular level: a mechanostimulation microchip and a silicone‐based cell stretcher. Using these tools, we show that ATP is released upon cell stretching and that extracellular ATP contributes to a major part of Ca2+ signalling induced by stretching in T24 cells. These results contribute to the increasing body of evidence for ATP signalling as an important component for the sensory function of urothelial cells. This encourages the development of drugs targeting P2 receptors to relieve suffering from overactive bladder disorder and incontinence.
Collapse
Affiliation(s)
- Na N Guan
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, Stockholm, Sweden.,Department of Urology, Karolinska University Hospital, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Nimish Sharma
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, Stockholm, Sweden.,Department of Urology, Karolinska University Hospital, Stockholm, Sweden
| | - Katarina Hallén-Grufman
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Edwin W H Jager
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden
| | - Karl Svennersten
- Department of Molecular Medicine and Surgery, Section of Urology, Karolinska Institutet, Stockholm, Sweden.,Department of Urology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|