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Liu J, Liu D, Zhang J, He W, Guo Y, Li Y, Chen P, DiSanto ME, Zhang X. Expression and functional activity of myosin II in hyperplastic prostates of varying volumes. Cell Signal 2023; 106:110658. [PMID: 36935086 DOI: 10.1016/j.cellsig.2023.110658] [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: 12/31/2022] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/19/2023]
Abstract
Prostate volume (PV) differs dramatically among benign prostatic hyperplasia (BPH) patients. Estimation of PV is important to guide the most appropriate pharmacologic or interventional treatment approach. However, the underlying pathophysiological mechanisms for the differences in PV remain unknown. We recently found that the myosin II system might participate in the etiology and development of BPH via static and dynamic factors. Our present study aims to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in hyperplastic prostates with varied PV. Human hyperplastic prostates and the testosterone-induced rat BPH model were employed for this study. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. Also, a BPH tissue microarray (TMA) was constructed to determine the correlations between myosin II isoforms with clinical parameters of BPH patients. With the increase of PV, the expression of NMMHC-A, NMMHC-C, SM-A and LC17b isoforms were increased, and the contractility of prostate smooth muscle was enhanced but force developed more slowly. Consistently, NMMHC-A, NMMHC-C, SM-A and LC17b were correlated positively with PV. Similar outcomes were also observed in the BPH rat model with different PVs. Alterations in the expression and function of myosin the II system may be involved in the pathophysiological mechanism of PV differences between BPH patients.
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Affiliation(s)
- Jianmin Liu
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Daoquan Liu
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Junchao Zhang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Weixiang He
- Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yuhang Guo
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yan Li
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Ping Chen
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Michael E DiSanto
- Department of Surgery and Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Xinhua Zhang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.
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SKA-31-induced activation of small-conductance calcium-activated potassium channels decreased modulation of detrusor smooth muscle function in a rat model of obesity. J Bioenerg Biomembr 2022; 54:135-144. [PMID: 35478071 DOI: 10.1007/s10863-022-09939-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 04/15/2022] [Indexed: 10/18/2022]
Abstract
Increased excitability and contractility of detrusor smooth muscle (DSM) cells are associated with overactive bladder (OAB), which is often induced by obesity. Small-conductance Ca2+-activated K+ (SK) channels regulate the excitability and contractility of DSM cells. Selective pharmacological activation of SK channels attenuates hyperpolarization and the decreased relaxation effect in DSM cells in obesity-induced OAB. However, additional data are needed to confirm the regulatory effect of SK channels on the function of DSM cells in obesity-related OAB. The tested hypothesis was that activation of SK channels decreases modulation of DSM function in a rat model of obesity-related OAB. Female Sprague Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD), weighed after 12 weeks, and subjected to urodynamic study, patch-clamp electrophysiology, and isometric tension recording. The average body weight and incidence of OAB were increased in the HFD group. Patch-clamp studies revealed that pharmacological activation of SK channels with SKA-31 had attenuated hyperpolarization of DSM cells. In addition, isometric tension recordings indicated that SKA-31 decreased relaxation of spontaneous phasic contractions of DSM strips in the HFD group. Attenuated function of SK channels increased the excitability and contractility of DSM cells, which contributed to the occurrence of OAB, suggesting that SK channels are potential therapeutic targets for control of OAB.
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Dupuis-Dowd F, Lavoie JP. Airway smooth muscle remodelling in mild and moderate equine asthma. Equine Vet J 2021; 54:865-874. [PMID: 34529300 DOI: 10.1111/evj.13514] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/15/2021] [Accepted: 09/03/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Airway smooth muscle remodelling in severe equine asthma includes both thickening of airway smooth muscle, resulting from hyperplasia and hypertrophy, and changes in contractility. However, airway smooth muscle changes have not been studied in milder forms of the disease. OBJECTIVES To investigate bronchial smooth muscle remodelling in horses with mild and moderate asthma (MEA). STUDY DESIGN Retrospective case-control study. METHODS The endobronchial biopsies from 18 horses with MEA referred to the Equine Hospital of the Université de Montréal and from seven healthy age-matched control horses were studied. The diagnosis was based on clinical signs and bronchoalveolar lavage fluid cytology. Airway smooth muscle cell proliferation was measured by quantifying the expression of the proliferating cell nuclear antigen (PCNA) using immunohistochemistry and histomorphometry. The expression of the (+)insert smooth muscle myosin heavy chain (SMMHC) isoform, an hypercontractile protein, was assessed by RT-qPCR. RESULTS Expression of the (+)insert SMMHC isoform in airway smooth muscle was approximately 1.5 times greater in horses with MEA compared with controls (P = .02, mean difference 0.01). Although there were no differences between groups in the proliferation of airway smooth muscle cells (P = .4) or myocyte density (P = .3, mean difference -0.6), the percentage of proliferating myocytes was correlated to pulmonary neutrophilia in horses with neutrophilic inflammation (P = .01, r = .80) and to the expression of the (+)insert SMMHC isoform in asthmatic horses (P = .03, r = .66). MAIN LIMITATIONS Small cohorts of horses were studied, and conclusions are limited to the central airways. CONCLUSIONS These results confirm the presence of bronchial smooth muscle remodelling in mild forms of equine asthma and pave the way for the development of biomarkers to measure asthma progression and response to therapy.
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Affiliation(s)
- Florence Dupuis-Dowd
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Québec, Canada
| | - Jean-Pierre Lavoie
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, Québec, Canada
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Changes in the expression and functional activities of Myosin II isoforms in human hyperplastic prostate. Clin Sci (Lond) 2021; 135:167-183. [PMID: 33393635 DOI: 10.1042/cs20201283] [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: 10/13/2020] [Revised: 12/05/2020] [Accepted: 01/04/2021] [Indexed: 01/21/2023]
Abstract
Benign prostatic hyperplasia (BPH) is a common disease among aging males with the etiology remaining unclear. We recently found myosin II was abundantly expressed in rat and cultured human prostate cells with permissive roles in the dynamic and static components. The present study aimed to explore the expression and functional activities of myosin II isoforms including smooth muscle (SM) myosin II (SMM II) and non-muscle myosin II (NMM II) in the hyperplastic prostate. Human prostate cell lines and tissues from normal human and BPH patients were used. Hematoxylin and Eosin (H&E), Masson's trichrome, immunohistochemical staining, in vitro organ bath, RT-polymerase chain reaction (PCR) and Western-blotting were performed. We further created cell models with NMM II isoforms silenced and proliferation, cycle, and apoptosis of prostate cells were determined by cell counting kit-8 (CCK-8) assay and flow cytometry. Hyperplastic prostate SM expressed more SM1 and LC17b isoforms compared with their alternatively spliced counterparts, favoring a slower more tonic-type contraction and greater force generation. For BPH group, blebbistatin (BLEB, a selective myosin II inhibitor), exhibited a stronger effect on relaxing phenylephrine (PE) pre-contracted prostate strips and inhibiting PE-induced contraction. Additionally, NMMHC-A and NMMHC-B were up-regulated in hyperplastic prostate with no change in NMMHC-C. Knockdown of NMMHC-A or NMMHC-B inhibited prostate cell proliferation and induced apoptosis, with no changes in cell cycle. Our novel data demonstrate that expression and functional activities of myosin II isoforms are altered in human hyperplastic prostate, suggesting a new pathological mechanism for BPH. Thus, the myosin II system may provide potential new therapeutic targets for BPH/lower urinary tract symptoms (LUTS).
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5
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Attenuated regulatory function of the small-conductance Ca 2+-activated K + channel in detrusor smooth muscle cells excitability in an obese rat model. Int Urol Nephrol 2020; 52:1851-1861. [PMID: 32399771 DOI: 10.1007/s11255-020-02487-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 04/29/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE Overactive bladder (OAB) is related to detrusor overactivity (DO), which is caused by the increased detrusor smooth muscle (DSM) cells excitability. Small-conductance Ca2+-activated K+ (SK) channels is a fundamental regulator of excitability and contractility in DSM cells. Obesity-related OAB is associated with the decreased expression and regulatory function of SK channels in DSM layer. However, the regulation role of SK channels in obesity-related OAB DSM cell excitability is still unknown. Here, we tested the hypothesis that obesity-related OAB is associated with reduced expression and activity of SK channels in DSM cells. METHODS Female Sprague-Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD) and weighed after 12 weeks. We performed urodynamic study, single-cell quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and patch-clamp electrophysiology. RESULTS Increased average body weights and urodynamically demonstrated OAB were observed in HFD rats. Single-cell qRT-PCR experiments discovered the decreased mRNA expression level of SK channel in DSM cell from HFD rats. Patch-clamp studies revealed that NS309, a SK channel activator, had an attenuated effect on membrane potential hyperpolarization in HFD DSM cells. In addition, the reduced whole cell SK channel currents were recorded in HFD DSM cells. CONCLUSIONS Attenuated SK channels expression and function, which results in the increased DSM cells excitability and contributes to DO, is discovered in obesity-related OAB DSM cells, suggesting that SK channels might be potential therapeutic targets to control OAB.
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6
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Li N, Ding H, Zhang P, Li Z, Liu Y, Wang P. Attenuated BK channel function promotes overactive bladder in a rat model of obesity. Aging (Albany NY) 2019; 11:6199-6216. [PMID: 31480021 PMCID: PMC6738405 DOI: 10.18632/aging.102182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/10/2019] [Indexed: 12/17/2022]
Abstract
Overactive bladder (OAB) is mostly observed in obese individuals, and is associated with enhanced excitability and contractility of the detrusor smooth muscle (DSM). Large-conductance voltage- and Ca2+-activated K+ (BK) channels reduce the excitability and contractility of the DSM. We tested whether obesity-induced OAB is associated with altered BK channel expression and activity in the DSM. Seven-week-old female Sprague-Dawley rats (N=80) were fed a normal or high-fat diet (HFD) for 12 weeks. HFD-fed rats exhibited a higher average bodyweight and urodynamically established detrusor overactivity. mRNA levels of the Kcnma1 (BKα subunit) and Kcnmb1 (BKβ1 subunit) in whole tissues and cells from the DSM were reduced in HFD-fed rats. A selective BK channel opener, NS1619, was then applied to DSM cells from the two groups of rats. Patch-clamp techniques revealed that spontaneous transient outward currents, NS1619-induced activation of spontaneous transient outward currents, and whole-cell BK currents, as well as NS1619-induced membrane hyperpolarization, were attenuated in DSM cells from HFD-fed rats. The relaxation effect of NS1619 on contractility was reduced in DSM strips from HFD-fed rats. Thus, impaired expression of Kcnma1 and Kcnmb1 in the DSM contributes to obesity-induced OAB, suggesting that BK channels could be a useful treatment targets in OAB.
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Affiliation(s)
- Ning Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
| | - Honglin Ding
- Department of Urology, Fourth Affiliated Hospital, China Medical University, Shenyang, Liaoning, China.,Department of Urology, Affiliated Hospital, Chifeng University, Chifeng, Neimeng, China
| | - Peng Zhang
- Department of General Surgery, Shenyang 242 Hospital, Shenyang, Liaoning, China
| | - Zizheng Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
| | - Yili Liu
- Department of Urology, Fourth Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
| | - Ping Wang
- Department of Urology, Fourth Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
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Wróbel A, Nowakowski Ł, Doboszewska U, Rechberger E, Bańczerowska-Górska M, Wlaźlak E, Zakrocka I, Wlaź P, Semczuk A, Dudka J, Poleszak E. Blebbistatin reveals beneficial effects on the cystometric parameters in an animal model of detrusor overactivity. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:843-850. [PMID: 30852655 PMCID: PMC7260150 DOI: 10.1007/s00210-019-01640-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 02/25/2019] [Indexed: 11/29/2022]
Abstract
The aims of the study were to determine the effectiveness of blebbistatin (BLEB) on detrusor overactivity (DO) in an animal model induced by retinyl acetate (RA) and, because of potential urothelial permeability, to evaluate the degenerative impact of BLEB on the urothelium. Three days after RA instillation into the urinary bladder, BLEB was administered into the bladder and immediately after cystometric assessment was performed. Furthermore, Evans Blue extravasation into bladder tissue and urothelium thickness were measured. Sixty female Wistar rats were used and randomly assigned to one of four groups (n = 15 in each group): (1) control, (2) RA, (3) BLEB, and (4) RA + BLEB. RA administration induced changes in cystometric parameters reflecting DO, as previously reported. Treatment with BLEB did not significantly alter cystometric parameters in rats which did not receive RA. Administration of BLEB to rats pretreated with RA reversed changes in cystometric parameters induced by RA in basal pressure, threshold pressure, detrusor overactivity index, amplitude of nonvoiding contractions, frequency of nonvoiding contractions, voided volume, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions. There were no significant differences in Evans Blue extravasation into bladder tissue or urothelium thickness between the groups. The current research provides new data on the possible utility of blebbistatin in the pharmacotherapy of DO, which is an important feature of overactive bladder (OAB). Further studies in human patients with DO/OAB are warranted to confirm these preclinical results.
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Affiliation(s)
- Andrzej Wróbel
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, 20-954, Lublin, Poland.
| | - Łukasz Nowakowski
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, 20-954, Lublin, Poland
| | - Urszula Doboszewska
- Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland.
| | - Ewa Rechberger
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, 20-954, Lublin, Poland
| | | | - Edyta Wlaźlak
- Clinic of Operative Gynecology and Gynecologic Oncology, 1st Department of Gynecology and Obstetrics, Medical University of Lodz, Wileńska 37, Łódź, 94-029, Poland
| | - Izabela Zakrocka
- Chair and Department of Nephrology, Medical University of Lublin, Jaczewskiego 8, 20-954, Lublin, Poland
| | - Piotr Wlaź
- Department of Animal Physiology, Institute of Biology and Biochemistry, Faculty of Biology and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Andrzej Semczuk
- Second Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, 20-954, Lublin, Poland
| | - Jarosław Dudka
- Chair and Department of Toxicology, Medical University of Lublin, Chodźki 8, 20-093, Lublin, Poland
| | - Ewa Poleszak
- Chair and Department of Applied Pharmacy, Medical University of Lublin, Chodźki 1, 20-093, Lublin, Poland
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Klee NS, McCarthy CG, Lewis S, McKenzie JL, Vincent JE, Webb RC. Urothelial Senescence in the Pathophysiology of Diabetic Bladder Dysfunction-A Novel Hypothesis. Front Surg 2018; 5:72. [PMID: 30564582 PMCID: PMC6288180 DOI: 10.3389/fsurg.2018.00072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 12/11/2022] Open
Abstract
Diabetic bladder dysfunction (DBD) is a well-recognized and common symptom affecting up to 50% of all diabetic patients. DBD has a broad range of clinical presentations ranging from overactive to underactive bladder symptoms that develops in middle-aged to elderly patients with long standing and poorly controlled diabetes. Low efficacy of current therapeutics and lifestyle interventions combined with high national healthcare costs highlight the need for more research into bladder dysfunction pathophysiology and novel treatment options. Cellular senescence is an age-related physiologic process in which cells undergo irreversible growth arrest induced by replicative exhaustion and damaging insults. While controlled senescence negatively regulates cell proliferation and promotes tissue regeneration, uncontrolled senescence is known to result in tissue dysfunction through enhanced secretion of inflammatory factors. This review presents previous scientific findings and current hypotheses that characterize diabetic bladder dysfunction. Further, we propose the novel hypothesis that cellular senescence within the urothelial layer of the bladder contributes to the pro-inflammatory/pro-oxidant environment and symptoms of diabetic bladder dysfunction. Our results show increased cellular senescence in the urothelial layer of the bladder; however, whether this phenomenon is the cause or effect of DBD is unknown. The urothelial layer of the bladder is made up of transitional epithelia specialized to contract and expand with demand and plays an active role in transmission by modulating afferent activity. Transition from normal functioning urothelial cells to secretory senescence cells would not only disrupt the barrier function of this layer but may result in altered signaling and sensation of bladder fullness; dysfunction of this layer is known to result in symptoms of frequency and urgency. Future DBD therapeutics may benefit from targeting and preventing early transition of urothelial cells to senescent cells.
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Affiliation(s)
- Nicole S Klee
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Cameron G McCarthy
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Steven Lewis
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Jaine L McKenzie
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States.,Department of Surgery, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Julie E Vincent
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - R Clinton Webb
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
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9
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Chen P, Xiao H, Huang W, Xu DQ, Guo YM, Wang X, Wang XH, DiSanto ME, Zhang XH. Testosterone regulates myosin II isoforms expression and functional activity in the rat prostate. Prostate 2018; 78:1283-1298. [PMID: 30073674 DOI: 10.1002/pros.23702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/11/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND Benign prostatic hyperplasia (BPH) is mainly caused by increased prostatic smooth muscle (SM) tone and prostatic volume. At the molecular level, SM myosin II (SMM II) and non-muscle myosin II (NMM II) mediate SM tone and cell proliferation while testosterone (T) plays a permissive role in the development of BPH. AIMS The novel objective of this study was to elucidate the effects of T on the proliferation and apoptosis of rat prostatic cells and SM contractility as well as related regulatory signaling pathways. MATERIALS AND METHODS Briefly, 36 male rats were divided into three groups (sham-operated, surgically castrated, and castrated with T supplementation). In vitro organ bath studies, competitive RT-PCR, Western-blotting analysis, Masson's trichrome staining, and immunofluorescence staining were performed. RESULTS Our data showed that castration dramatically increased prostatic SM contractility and SM MHC immunostaining revealed a relatively increased SM cell numbers in the stroma. T deprivation altered prostate SMM II isoform composition with upregulation of SM-B and SM2 but downregulation of LC17a, favoring a faster more phasic-type contraction. Moreover, protein expressions of MLCK, p-MLCP, RhoB, ROCK1, and ROCK2 increased in castrated rats. Meanwhile NMM II heavy chain isoforms A, B, and C (NMMHC-A, B, and C isoforms) were altered by castration which may be linked to decreased cell proliferation and increased apoptosis. CONCLUSION Our novel data demonstrated T regulates SMM II and NMM II and their functional activities in rat prostate and T ablation not only decreases prostate size (static component) but also changes the prostatic SM tone (dynamic component).
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Affiliation(s)
- Ping Chen
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
| | - He Xiao
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
| | - Wei Huang
- Department of Urology, People's Hospital of Tuanfeng County, Hubei, China
| | - De-Qiang Xu
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
| | - Yu-Ming Guo
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
| | - Xiao Wang
- Department of Urology, People's Hospital of Wuhan University, Wuhan, China
| | - Xing-Huan Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
| | - Michael E DiSanto
- Departments of Biomedical Sciences and Surgery, Cooper Medical School of Rowan University, Camden, New Jersey
| | - Xin-Hua Zhang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, P.R. China
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10
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Li N, Ding H, Li Z, Liu Y, Wang P. Effect of high-fat diet-induced obesity on the small-conductance Ca 2+-activated K + channel function affecting the contractility of rat detrusor smooth muscle. Int Urol Nephrol 2018; 51:61-72. [PMID: 30361965 DOI: 10.1007/s11255-018-2016-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/19/2018] [Indexed: 12/01/2022]
Abstract
PURPOSE Obesity usually induces overactive bladder (OAB) associated with detrusor overactivity, which is related to increased contractility of the detrusor smooth muscle (DSM). Small-conductance Ca2+-activated K+ (SK) channels play a constitutive role in the regulation of DSM contractility. However, the role of SK channels in the DSM changes in obesity-related OAB is still unknown. Here, we tested the hypothesis that obesity-related OAB is associated with reduced expression and activity of SK channels in DSM and that SK channels activation is a potential treatment for OAB. METHODS Female Sprague-Dawley rats were fed a normal diet (ND) or a high-fat diet (HFD) and weighed after 12 weeks. Urodynamic studies, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and isometric tension recording were performed. RESULTS Increased average body weights and urodynamically demonstrated OAB were observed in HFD rats. qRT-PCR experiments revealed a decrease in the mRNA expression level of SK channel in DSM tissue of the HFD rats. Isometric tension recordings indicated an attenuated relaxation effect of NS309 on the spontaneous phasic and electrical field stimulation-induced contractions that occurred via SK channel activation in HFD DSM strips. CONCLUSIONS Reduced expression and activity of SK channels in the DSM contribute to obesity-related OAB, indicating that SK channels are a potential therapeutic target for OAB.
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Affiliation(s)
- Ning Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Honglin Ding
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.,Department of Urology, Affiliated Hospital, Chifeng University, 42 Wangfu Street, Chifeng, Neimeng, China
| | - Zizheng Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Yili Liu
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.
| | - Ping Wang
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
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11
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Blebbistatin modulates prostatic cell growth and contrapctility through myosin II signaling. Clin Sci (Lond) 2018; 132:2189-2205. [PMID: 30279228 DOI: 10.1042/cs20180294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 09/13/2018] [Accepted: 10/01/2018] [Indexed: 01/07/2023]
Abstract
To investigate the effect of blebbistatin (BLEB, a selective myosin inhibitor) on regulating contractility and growth of prostate cells and to provide insight into possible mechanisms associated with these actions. BLEB was incubated with cell lines of BPH-1 and WPMY-1, and intraprostatically injected into rats. Cell growth was determined by flow cytometry, and in vitro organ bath studies were performed to explore muscle contractility. Smooth muscle (SM) myosin isoform (SM1/2, SM-A/B, and LC17a/b) expression was determined via competitive reverse transcriptase PCR. SM myosin heavy chain (MHC), non-muscle (NM) MHC isoforms (NMMHC-A and NMMHC-B), and proteins related to cell apoptosis were further analyzed via Western blotting. Masson's trichrome staining was applied to tissue sections. BLEB could dose-dependently trigger apoptosis and retard the growth of BPH-1 and WPMY-1. Consistent with in vitro effect, administration of BLEB to the prostate could decrease rat prostatic epithelial and SM cells via increased apoptosis. Western blotting confirmed the effects of BLEB on inducing apoptosis through a mechanism involving MLC20 dephosphorylation with down-regulation of Bcl-2 and up-regulation of BAX and cleaved caspase 3. Meanwhile, NMMHC-A and NMMHC-B, the downstream proteins of MLC20, were found significantly attenuated in BPH-1 and WPMY-1 cells, as well as rat prostate tissues. Additionally, BLEB decreased SM cell number and SM MHC expression, along with attenuated phenylephrine-induced contraction and altered prostate SMM isoform composition with up-regulation of SM-B and down-regulation of LC17a, favoring a faster contraction. Our novel data demonstrate BLEB regulated myosin expression and functional activity. The mechanism involved MLC20 dephosphorylation and altered SMM isoform composition.
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12
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Chen P, Yin J, Guo YM, Xiao H, Wang XH, DiSanto ME, Zhang XH. The expression and functional activities of smooth muscle myosin and non-muscle myosin isoforms in rat prostate. J Cell Mol Med 2017; 22:576-588. [PMID: 28990332 PMCID: PMC5742693 DOI: 10.1111/jcmm.13345] [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: 12/22/2016] [Accepted: 07/10/2017] [Indexed: 11/30/2022] Open
Abstract
Benign prostatic hyperplasia (BPH) is mainly caused by increased prostatic smooth muscle (SM) tone and volume. SM myosin (SMM) and non-muscle myosin (NMM) play important roles in mediating SM tone and cell proliferation, but these molecules have been less studied in the prostate. Rat prostate and cultured primary human prostate SM and epithelial cells were utilized. In vitro organ bath studies were performed to explore contractility of rat prostate. SMM isoforms, including SM myosin heavy chain (MHC) isoforms (SM1/2 and SM-A/B) and myosin light chain 17 isoforms (LC17a/b ), and isoform ratios were determined via competitive RT-PCR. SM MHC and NM MHC isoforms (NMMHC-A, NMMHC-B and NMMHC-C) were further analysed via Western blotting and immunofluorescence microscopy. Prostatic SM generated significant force induced by phenylephrine with an intermediate tonicity between phasic bladder and tonic aorta type contractility. Correlating with this kind of intermediate tonicity, rat prostate mainly expressed LC17a and SM1 but with relatively equal expression of SM-A/SM-B at the mRNA level. Meanwhile, isoforms of NMMHC-A, B, C were also abundantly present in rat prostate with SMM present only in the stroma, while NMMHC-A, B, C were present both in the stroma and endothelial. Additionally, the SMM selective inhibitor blebbistatin could potently relax phenylephrine pre-contracted prostate SM. In conclusion, our novel data demonstrated the expression and functional activities of SMM and NMM isoforms in the rat prostate. It is suggested that the isoforms of SMM and NMM could play important roles in BPH development and bladder outlet obstruction.
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Affiliation(s)
- Ping Chen
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jing Yin
- Department of Rehabilitation, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yu-Ming Guo
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - He Xiao
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xing-Huan Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Michael E DiSanto
- Department of Surgery and Biomedical Sciences of Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Xin-Hua Zhang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
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Li N, Ding H, He X, Li Z, Liu Y. Expression and function of the small-conductance Ca 2+-activated K + channel is decreased in urinary bladder smooth muscle cells from female guinea pig with partial bladder outlet obstruction. Int Urol Nephrol 2017; 49:1147-1155. [PMID: 28417339 DOI: 10.1007/s11255-017-1592-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/10/2017] [Indexed: 01/10/2023]
Abstract
PURPOSE Overactive bladder (OAB), usually accompanied by partial bladder outlet obstruction (PBOO), is associated with detrusor overactivity (DO) which is related to the increased urinary bladder smooth muscle (UBSM) cells excitability. Small-conductance Ca2+-activated K+ (SK) channels play a constitutive regulatory role of UBSM excitability and contractility. PBOO is associated with the decreased SK channels mRNA expression and the attenuated regulative effect of SK channels on UBSM contractility. However, the regulation of SK channels in PBOO UBSM cell excitability is less clear. Here, we tested the hypothesis that PBOO is associated with decreased expression and function of SK channels in UBSM cells and that SK channels are a potential target for the treatment of OAB. METHODS Cystometry indicated that DO was achieved 2 weeks after PBOO in female guinea pigs. Using this animal model, we conducted single-cell quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and patch-clamp electrophysiology. RESULTS The single-cell qRT-PCR experiments indicated the reduced SK channel mRNA expression in PBOO UBSM cells. Patch-clamp studies revealed that NS309 had a diminished effect on resting membrane potential hyperpolarization via the activation of SK channels in PBOO UBSM cells. Moreover, attenuated whole-cell SK channel currents were demonstrated in PBOO UBSM cells. CONCLUSIONS The attenuated expression and function of SK channels, which results in the increased UBSM cells excitability and contributes to DO, was discovered in PBOO UBSM cells, suggesting that SK channels might be potential therapeutic targets for the control of OAB.
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Affiliation(s)
- Ning Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Honglin Ding
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Xiaoning He
- Department of Stomatology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Zizheng Li
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China
| | - Yili Liu
- Department of Urology, Fourth Affiliated Hospital, China Medical University, 4 Chongshan East Road, Shenyang, Liaoning, China.
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Li N, He X, Li Z, Liu Y, Wang P. Partial bladder outlet obstruction is associated with decreased expression and function of the small-conductance Ca2+-activated K+ channel in guinea pig detrusor smooth muscle. Int Urol Nephrol 2016; 49:17-26. [DOI: 10.1007/s11255-016-1455-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 11/03/2016] [Indexed: 10/24/2022]
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Hypolite JA, Malykhina AP. Regulation of urinary bladder function by protein kinase C in physiology and pathophysiology. BMC Urol 2015; 15:110. [PMID: 26538012 PMCID: PMC4634593 DOI: 10.1186/s12894-015-0106-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/22/2015] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Protein kinase C (PKC) is expressed in many tissues and organs including the urinary bladder, however, its role in bladder physiology and pathophysiology is still evolving. The aim of this review was to evaluate available evidence on the involvement of PKC in regulation of detrusor contractility, muscle tone of the bladder wall, spontaneous contractile activity and bladder function under physiological and pathophysiological conditions. METHODS This is a non-systematic review of the published literature which summarizes the available animal and human data on the role of PKC signaling in the urinary bladder under different physiological and pathophysiological conditions. A wide PubMed search was performed including the combination of the following keywords: "urinary bladder", "PKC", "detrusor contractility", "bladder smooth muscle", "detrusor relaxation", "peak force", "detrusor underactivity", "partial bladder outlet obstruction", "voltage-gated channels", "bladder nerves", "PKC inhibitors", "PKC activators". Retrieved articles were individually screened for the relevance to the topic of this review with 91 citations being selected and included in the data analysis. DISCUSSION Urinary bladder function includes the ability to store urine at low intravesical pressure followed by a subsequent release of bladder contents due to a rapid phasic contraction that is maintained long enough to ensure complete emptying. This review summarizes the current concepts regarding the potential contribution of PKC to contractility, physiological voiding, and related signaling mechanisms involved in the control of both the storage and emptying phases of the micturition cycle, and in dysfunctional voiding. Previous studies linked PKC activation exclusively with an increase in generation of the peak force of smooth muscle contraction, and maximum force generation in the lower urinary tract. More recent data suggests that PKC presents a broader range of effects on urinary bladder function including regulation of storage, emptying, excitability of the detrusor, and bladder innervation. In this review, we evaluated the mechanisms of peripheral and local regulation of PKC signaling in the urinary bladder, and their impact on different phases of the micturition cycle under physiological and pathophysiological conditions.
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Affiliation(s)
- Joseph A Hypolite
- Division of Urology, Department of Surgery, University of Colorado Denver, Anschutz Medical Campus, 12700 E 19th Ave. Mail Stop C317, Aurora, CO, 80045, USA.
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver, Anschutz Medical Campus, 12700 E 19th Ave. Mail Stop C317, Aurora, CO, 80045, USA.
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Hypolite JA, Chang S, Wein AJ, Chacko S, Malykhina AP. Protein kinase C modulates frequency of micturition and non-voiding contractions in the urinary bladder via neuronal and myogenic mechanisms. BMC Urol 2015; 15:34. [PMID: 25896919 PMCID: PMC4407874 DOI: 10.1186/s12894-015-0030-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/15/2015] [Indexed: 11/10/2022] Open
Abstract
Background Protein Kinase C (PKC) dysfunction is implicated in a variety of smooth muscle disorders including detrusor overactivity associated with frequency and urgency of micturition. In this study, we aimed to evaluate the modulatory effects of endogenous PKC-dependent pathways on bladder storage and emptying function. Methods We utilized in vivo cystometry and in vitro organ bath studies using isolated bladder muscle strips (BMS) from rats to measure contractility, intravesical pressure, and voided volume. Both in vitro and in vivo results were statistically analyzed using one-way repeated measures ANOVA between the groups followed by Bonferroni’s post-test, as appropriate (Systat Software Inc., San Jose, CA). Results Effects of PKC activators, phorbol-12,13-dibutyrate (PDBu), and phorbol-12,13-myristate (PMA), were concentration-dependent, with high concentrations increasing frequency of micturition, and sensitivity of intramural nerves to electrical field stimulation (EFS), in vitro, while lower concentrations had no effect on BMS sensitivity to EFS. The PKC inhibitors, bisindolylmaleimide1 (Bim-1), (28 nM), and Ro318220 (50 μM) triggered an increase in the number of non-voiding contractions (NVC), and a decrease in the voided volume associated with reduced ability to maintain contractile force upon EFS, but did not affect peak force in vitro. Both low (50 nM) and high PDBu 1 micromolar (1uM) decreased the sensitivity of BMS to carbachol. Application of a low concentration of PDBu inhibited spontaneous contractions, in vitro, and Bim-1-induced NVC, and restored normal voiding frequency during urodynamic recordings in vivo. Conclusions In summary, the effects of low PKC stimulation include inhibition of smooth muscle contractile responses, whereas high levels of PKC stimulation increased nerve-mediated contractions in vitro, and micturition contractions in vivo. These results indicate that endogenous PKC signaling displays a concentration-dependent contraction profile in the urinary bladder via both smooth muscle and nerve-mediated pathways.
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Affiliation(s)
- Joseph A Hypolite
- Division of Urology, Department of Surgery, University of Colorado Denver, Anschutz Medical Campus,12700 E 19th Ave, Mail Stop C317, Aurora, CO, 80045, USA.
| | - Shaohua Chang
- Department of Surgery, Cooper University, Camden, NJ, USA.
| | - Alan J Wein
- Division of Urology, Department of Surgery, University of Pennsylvania, Philadelphia, PA, USA.
| | - Samuel Chacko
- Division of Urology, Department of Surgery, University of Pennsylvania, Philadelphia, PA, USA.
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver, Anschutz Medical Campus,12700 E 19th Ave, Mail Stop C317, Aurora, CO, 80045, USA.
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Asthma "of horses and men"--how can equine heaves help us better understand human asthma immunopathology and its functional consequences? Mol Immunol 2014; 66:97-105. [PMID: 25547716 DOI: 10.1016/j.molimm.2014.12.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 11/30/2014] [Accepted: 12/07/2014] [Indexed: 12/20/2022]
Abstract
Animal models have been studied to unravel etiological, immunopathological, and genetic attributes leading to asthma. However, while experiments in which the disease is artificially induced have helped discovering biological and molecular pathways leading to allergic airway inflammation, their contribution to the understanding of the causality of the disease has been more limited. Horses naturally suffer from an asthma-like condition called "heaves" which presents sticking similarities with human asthma. It is characterized by reversible airway obstruction, airway neutrophilic inflammation, and a predominant Th2 immune response. This model allows one to investigate the role of neutrophils in asthma, which remains contentious, the regulation of chronic neutrophilic inflammation, and their possible implication in pulmonary allergic responses. Furthermore, the pulmonary remodeling features in heaves closely resemble those of human asthma, which makes this model unique to investigate the kinetics, reversibility, as well as the physiological consequences of tissue remodeling. In conclusion, heaves and asthma share common clinical presentation and also important immunological and tissue remodeling features. This makes heaves an ideal model for the discovery of novel pathways implicated in the asthmatic inflammation and associated tissue remodeling.
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18
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Boivin R, Vargas A, Lefebvre-Lavoie J, Lauzon AM, Lavoie JP. Inhaled corticosteroids modulate the (+)insert smooth muscle myosin heavy chain in the equine asthmatic airways. Thorax 2014; 69:1113-9. [PMID: 25205586 DOI: 10.1136/thoraxjnl-2014-205572] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
RATIONALE Overexpression of the (+)insert smooth muscle myosin heavy chain (SMMHC) isoform could contribute to airway bronchospasm by increasing the velocity of contraction. Whether the (+)insert isoform is present in the small airways and its expression is reversible in asthma are unknown. OBJECTIVES To determine the anatomical location and the expression kinetics of the (+)insert SMMHC isoform in airways of horses with heaves and to evaluate its modulation in response to disease status. METHODS We evaluated the (+)insert SMMHC isoform in the airways of horses with heaves during disease exacerbation and remission, and in controls. The expression kinetics of the SMMHC (+)insert was then assessed at multiple time points in two studies: first, in horses with heaves treated for a 1-year period with antigen avoidance alone, inhaled corticosteroids alone or both; second, in horses with heaves before and after a 30-day natural antigen exposure. Gene expression analysis was assessed by quantitative PCR and protein expression was confirmed by targeted mass spectrometry. MEASUREMENTS AND MAIN RESULTS The (+)insert SMMHC isoform was significantly increased in central and peripheral airways, but not in the trachea of heaves-affected horses in clinical exacerbation when compared horses with heaves in remission and controls. Both corticosteroid administration and antigen avoidance led to a significant reduction of the (+)insert expression in the airways. The (+)insert SMMHC isoform was not significantly increased in airways after 1 month of antigenic re-exposure. CONCLUSIONS The (+)insert SMMHC expression is increased throughout the bronchial tree in horses with heaves and reversible by corticosteroids administration and antigen avoidance.
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Affiliation(s)
- Roxane Boivin
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - Amandine Vargas
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - Josiane Lefebvre-Lavoie
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - Anne-Marie Lauzon
- Meakins-Christie Laboratory, Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Jean-Pierre Lavoie
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
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Boopathi E, Gomes C, Zderic SA, Malkowicz B, Chakrabarti R, Patel DP, Wein AJ, Chacko S. Mechanical stretch upregulates proteins involved in Ca2+ sensitization in urinary bladder smooth muscle hypertrophy. Am J Physiol Cell Physiol 2014; 307:C542-53. [PMID: 25031021 DOI: 10.1152/ajpcell.00033.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Partial bladder outlet obstruction (pBOO)-induced remodeling of bladder detrusor smooth muscle (DSM) is associated with the modulation of cell signals regulating contraction. We analyzed the DSM from obstructed murine urinary bladders for the temporal regulation of RhoA GTPase and Rho-activated kinase (ROCK), which are linked to Ca(2+) sensitization. In addition, the effects of equibiaxial cell stretch, a condition thought to be associated with pBOO-induced bladder wall smooth muscle hypertrophy and voiding frequency, on the expression of RhoA, ROCK, and C-kinase-activated protein phosphatase I inhibitor (CPI-17) were investigated. DSM from 1-, 3-, 7-, and 14-day obstructed male mice bladders and benign prostatic hyperplasia (BPH)-induced obstructed human bladders revealed overexpression of RhoA and ROCK-β at the mRNA and protein levels compared with control. Primary human bladder myocytes seeded onto type I collagen-coated elastic silicone membranes were subjected to cyclic equibiaxial stretch, mimicking the cellular mechanical stretch in the bladder in vivo, and analyzed for the expression of RhoA, ROCK-β, and CPI-17. Stretch caused a significant increase of RhoA, ROCKβ, and CPI-17 expression. The stretch-induced increase in CPI-17 expression occurs at the transcriptional level and is associated with CPI-17 promoter binding by GATA-6 and NF-κB, the transcription factors responsible for CPI-17 gene transcription. Cell stretch caused by bladder overdistension in pBOO is the likely mechanism for initiating overexpression of the signaling proteins regulating DSM tone.
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Affiliation(s)
- Ettickan Boopathi
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Cristiano Gomes
- Hospital das Clinicas, University of Sao Paulo School of Medicine, Sao Paulo, Brazil
| | - Stephen A Zderic
- Department of Urology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Bruce Malkowicz
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Ranjita Chakrabarti
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Darshan P Patel
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Alan J Wein
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Samuel Chacko
- Division of Urology, Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania; Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;
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20
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Jock M, Leggett RE, Schuler C, Callaghan C, Levin RM. Effect of partial bladder outlet obstruction and reversal on rabbit bladder physiology and biochemistry: duration of recovery period and severity of function. BJU Int 2014; 114:946-54. [DOI: 10.1111/bju.12687] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Marley Jock
- Albany College of Pharmacy and Health Sciences; Albany NY USA
| | | | | | | | - Robert M. Levin
- Albany College of Pharmacy and Health Sciences; Albany NY USA
- Stratton VA Medical Center; Albany NY USA
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21
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Lentle RG, Reynolds GW, Janssen PWM. Gastrointestinal tone; its genesis and contribution to the physical processes of digestion. Neurogastroenterol Motil 2013; 25:931-42. [PMID: 24028606 DOI: 10.1111/nmo.12223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/08/2013] [Indexed: 12/24/2022]
Abstract
BACKGROUND Myogenic tone has long been recognised as an important component of gastrointestinal motility. Recent work has clarified the cellular mechanisms that engender tone and the neurogenic and mechanical stimuli that modulate it but has also highlighted cellular and regional specialisation in these mechanisms within the GI tract. Smooth muscle in all segments of the gut has the capability of latching, i.e. can generate ongoing specific rather than tetanic tone. This is likely modulated by both direct and indirect input from agonists such as acetylcholine and mechanoreceptors, the latter originating in ICC-IM, smooth muscle cells or elements of the ENS. Tonic contraction can occur in the absence of phasic contractions or concurrent with them, and it can modulate wall compliance and the capacity of particular segments, thereby affecting the level of on-flow and mixing, both luminal and adjacent to the mucosa. PURPOSE The review seeks to provide an overview of our understanding of the mechanism by which tone is generated and maintained, highlighting its modulation by neurogenic and mechanical stimuli, its mechanical consequences in the walls of the various segments of the gastrointestinal tract and its contribution to flow and mixing of contained digesta.
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Affiliation(s)
- R G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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22
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Age-related alterations in regeneration of the urinary bladder after subtotal cystectomy. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 183:1585-1595. [PMID: 24012523 DOI: 10.1016/j.ajpath.2013.07.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 07/02/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
Prior work documented that surgical removal of approximately 70% of the bladder (subtotal cystectomy) in 12-week-old female rats induced complete functional regeneration of the bladder within 8 weeks. To determine whether animal age affects bladder regeneration, female F344 rats aged 12 weeks (young) and 12 months (old) underwent subtotal cystectomy, and then were evaluated from 1 to 26 weeks after subtotal cystectomy. At 26 weeks after subtotal cystectomy, bladder capacity in young animals was indistinguishable from that in age-matched controls, but bladder capacity in old animals was only approximately 56% of that in age-matched controls. There was no detectable difference in residual volume among treatment groups, but the diminished regeneration in old animals was associated with a corresponding increase in the ratio of residual volume to micturition volume. The majority of old animals exhibited evidence of chronic kidney damage after subtotal cystectomy. Maximal contraction of bladder strips to electrical field stimulation, as well as activation with carbachol, phenylephrine, and KCl, were lower in old than in young animals at 26 weeks after subtotal cystectomy. Immunostaining with proliferating cell nuclear antigen and Von Willebrand factor revealed delayed and/or diminished proliferative and angiogenic responses, respectively, in old animals. These results confirm prior work and suggest that multiple mechanisms may contribute to an age-related decline in the regenerative capacity of the bladder.
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Jiang JX, Aitken KJ, Sotiropolous C, Kirwan T, Panchal T, Zhang N, Pu S, Wodak S, Tolg C, Bägli DJ. Phenotypic switching induced by damaged matrix is associated with DNA methyltransferase 3A (DNMT3A) activity and nuclear localization in smooth muscle cells (SMC). PLoS One 2013; 8:e69089. [PMID: 24282625 PMCID: PMC3735580 DOI: 10.1371/journal.pone.0069089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 06/09/2013] [Indexed: 12/27/2022] Open
Abstract
Extracellular matrix changes are often crucial inciting events for fibroproliferative disease. Epigenetic changes, specifically DNA methylation, are critical factors underlying differentiated phenotypes. We examined the dependency of matrix-induced fibroproliferation and SMC phenotype on DNA methyltransferases. The cooperativity of matrix with growth factors, cell density and hypoxia was also examined. Primary rat visceral SMC of early passage (0–2) were plated on native collagen or damaged/heat-denatured collagen. Hypoxia was induced with 3% O2 (balanced 5% CO2 and 95% N2) over 48 hours. Inhibitors were applied 2–3 hours after cells were plated on matrix, or immediately before hypoxia. Cells were fixed and stained for DNMT3A and smooth muscle actin (SMA) or smooth muscle myosin heavy chain. Illumina 450 K array of CpG sites was performed on bisulfite-converted DNA from smooth muscle cells on damaged matrix vs native collagen. Matrix exquisitely regulates DNMT3A localization and expression, and influences differentiation in SMCs exposed to denatured matrix +/− hypoxia. Analysis of DNA methylation signatures showed that Matrix caused significant DNA methylation alterations in a discrete number of CpG sites proximal to genes related to SMC differentiation. Matrix has a profound effect on the regulation of SMC phenotype, which is associated with altered expression, localization of DNMTs and discrete changes DNA methylation.
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Affiliation(s)
- Jia-Xin Jiang
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Karen J. Aitken
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
- * E-mail:
| | - Chris Sotiropolous
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Tyler Kirwan
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Trupti Panchal
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Nicole Zhang
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Shuye Pu
- Centre for Computational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Shoshana Wodak
- Centre for Computational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Cornelia Tolg
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Darius J. Bägli
- Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- Division of Urology, Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Sciences, Department of Surgery, University of Toronto, Toronto, Ontario, Canada
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GATA-6 and NF-κB activate CPI-17 gene transcription and regulate Ca2+ sensitization of smooth muscle contraction. Mol Cell Biol 2012; 33:1085-102. [PMID: 23275439 DOI: 10.1128/mcb.00626-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Protein kinase C (PKC)-potentiated inhibitory protein of 17 kDa (CPI-17) inhibits myosin light chain phosphatase, altering the levels of myosin light chain phosphorylation and Ca(2+) sensitivity in smooth muscle. In this study, we characterized the CPI-17 promoter and identified binding sites for GATA-6 and nuclear factor kappa B (NF-κB). GATA-6 and NF-κB upregulated CPI-17 expression in cultured human and mouse bladder smooth muscle (BSM) cells in an additive manner. CPI-17 expression was decreased upon GATA-6 silencing in cultured BSM cells and in BSM from NF-κB knockout (KO) mice. Moreover, force maintenance by BSM strips from KO mice was decreased compared with the force maintenance of BSM strips from wild-type mice. GATA-6 and NF-κB overexpression was associated with CPI-17 overexpression in BSM from men with benign prostatic hyperplasia (BPH)-induced bladder hypertrophy and in a mouse model of bladder outlet obstruction. Thus, aberrant expression of NF-κB and GATA-6 deregulates CPI-17 expression and the contractile function of smooth muscle. Our data provide insight into how GATA-6 and NF-κB mediate CPI-17 transcription, PKC-mediated signaling, and BSM remodeling associated with lower urinary tract symptoms in patients with BPH.
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Wang T, Kendig DM, Chang S, Trappanese DM, Chacko S, Moreland RS. Bladder smooth muscle organ culture preparation maintains the contractile phenotype. Am J Physiol Renal Physiol 2012; 303:F1382-97. [PMID: 22896042 PMCID: PMC3518193 DOI: 10.1152/ajprenal.00261.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 08/13/2012] [Indexed: 01/26/2023] Open
Abstract
Smooth muscle cells, when subjected to culture, modulate from a contractile to a secretory phenotype. This has hampered the use of cell culture for molecular techniques to study the regulation of smooth muscle biology. The goal of this study was to develop a new organ culture model of bladder smooth muscle (BSM) that would maintain the contractile phenotype and aid in the study of BSM biology. Our results showed that strips of BSM subjected to up to 9 days of organ culture maintained their contractile phenotype, including the ability to achieve near-control levels of force with a temporal profile similar to that of noncultured tissues. The technical aspects of our organ culture preparation that were responsible, in part, for the maintenance of the contractile phenotype were a slight longitudinal stretch during culture and subjection of the strips to daily contraction-relaxation. The tissues contained viable cells throughout the cross section of the strips. There was an increase in extracellular collagenous matrix, resulting in a leftward shift in the passive length-tension relationship. There were no significant changes in the content of smooth muscle-specific α-actin, calponin, h-caldesmon, total myosin heavy chain, protein kinase G, Rho kinase-I, or the ratio of SM1 to SM2 myosin isoforms. Moreover the organ cultured tissues maintained functional voltage-gated calcium channels and large-conductance calcium-activated potassium channels. Therefore, we propose that this novel BSM organ culture model maintains the contractile phenotype and will be a valuable tool for the use in cellular/molecular biology studies of bladder myocytes.
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Affiliation(s)
- Tanchun Wang
- Dept. of Pharmacology and Physiology, Drexel Univ. College of Medicine, 245 N 15th St., MS 488, Philadelphia, PA 19102, USA
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Zderic SA, Chacko S. Alterations in the contractile phenotype of the bladder: lessons for understanding physiological and pathological remodelling of smooth muscle. J Cell Mol Med 2012; 16:203-17. [PMID: 21707917 PMCID: PMC3289974 DOI: 10.1111/j.1582-4934.2011.01368.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The contractile properties of the urinary bladder are changed by the conditions of normal development and partial bladder outlet obstruction. This change in the contractile phenotype is accompanied by changes in the regulatory cascades and filaments that regulate contractility. This review focuses on such changes during the course of normal development and in response to obstruction. Our goal is to discuss the experimental evidence that has accumulated from work in animal models and correlate these findings with the human voiding phenotype.
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Affiliation(s)
- Stephen A Zderic
- The John W Duckett Jr Center for Pediatric Urology at The Children's Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA 19104, USA.
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27
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McGonagle E, Smith A, Butler S, Sliwoski J, Valentino R, Canning D, Zderic SA. Water avoidance stress results in an altered voiding phenotype in male mice. Neurourol Urodyn 2012; 31:1185-9. [PMID: 22473515 DOI: 10.1002/nau.22207] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 01/10/2012] [Indexed: 11/07/2022]
Abstract
AIMS We set out to characterize the voiding phenotypes of male mice to a water avoidance stress (WAS) protocol and compare the molecular changes with those induced by surgically induced partial bladder outlet obstruction (pBOO). METHODS Six-week-old male Swiss Webster mice housed with sibling littermates were individually placed on a platform centered in the middle of a water filled basin for 1 hr daily for 4 weeks. A non stressed cohort of sibling littermates served as controls. Measured end points included voiding frequency, voided volume, bladder mass, and in vivo cystometry. Molecular end points included myosin heavy chain (MHC) isoform distribution by PCR, and nuclear translocation of hypoxia inducible factor (HIF1α) and the nuclear factor of activated T-cells (NFAT) by gel shift assay. These molecular endpoints were compared with samples from male mice undergoing anatomic pBOO. RESULTS WAS resulted in increased average voided volumes and bladder mass, and a decrease in voiding frequency (P < 0.05). The slower MHC A isoform was only expressed in the pBOO group that developed severe hypertrophy. Gel shift assays revealed substantial increases in HIF1-α nuclear translocation in the group subjected to pBOO that developed severe hypertrophy but minimal changes in the pBOO group that developed minimal hypertrophy and the swim stress groups. CONCLUSIONS The WAS model induces moderate bladder wall hypertrophy in the absence of any surgical manipulation.
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Affiliation(s)
- Erin McGonagle
- John W. Duckett Center for Pediatric Urology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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Zhang X, Kanika ND, Melman A, DiSanto ME. Smooth muscle myosin expression, isoform composition, and functional activities in rat corpus cavernosum altered by the streptozotocin-induced type 1 diabetes. Am J Physiol Endocrinol Metab 2012; 302:E32-42. [PMID: 21917637 PMCID: PMC3328089 DOI: 10.1152/ajpendo.00231.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Diabetes mellitus (DM) is a quite common chronic disease, and the prevalence of erectile dysfunction (ED) is three times higher in this large population. Although diabetes-related ED has been studied extensively, the actin-myosin contractile apparatus was not examined. The mRNAs encoding smooth muscle myosin (SMM) heavy chains (MHC) and essential light chains (LC(17)) exist as several different alternatively spliced isoforms with distinct contractile properties. Recently, we provided novel data that blebbistatin (BLEB), a specific myosin II inhibitor, potently relaxed corpus cavernosum smooth muscle (CCSM). In this study, we examine whether diabetes alters SMM expression, alternative splicing, and/or functional activities, including sensitivity to BLEB. By using streptozotocin (STZ)-induced 2-mo diabetic rats, functional activities were tested in vivo by intracavernous pressure (ICP) recording during cavernous nerve stimulation and in vitro via organ bath contractility studies. SMM isoform composition was analyzed by competitive RT-PCR and total SMM, myocardin, and embryonic SMM (SMemb) expression by real-time RT-PCR. Results revealed that the blood glucose level of STZ rats was 407.0 vs. 129.5 mg/dl (control). STZ rats exhibited ED confirmed by significantly increased CCSM contractile response to phenylephrine and decreased ICP response. For STZ rats, SM-B, LC(17a) and SM2 isoforms, total SMM, and myocardin expression increased, whereas SM-A, LC(17b), and SM1 isoforms were decreased, with SMemb unchanged. BLEB was significantly more effective in relaxing STZ CCSM both in vitro and in vivo. Thus we demonstrated a novel diabetes-specific effect on alternative splicing of the SMM heavy chain and essential light chain genes to a SMM isoform composition favoring a heightened contractility and ED. A switch to a more contractile phenotype was supported further by total SMM expression increase. Moreover, the change in CCSM phenotype was associated with an increased sensitivity to BLEB, which may serve as a novel pharmacotherapy for ED.
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Affiliation(s)
- Xinhua Zhang
- Department of Urology, Albert Einstein College of Medicine, Bronx, NY, USA
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Cheung MC, Evans JG, McKenna B, Ehrlich DJ. Deep ultraviolet mapping of intracellular protein and nucleic acid in femtograms per pixel. Cytometry A 2011; 79:920-32. [PMID: 21796773 PMCID: PMC3199293 DOI: 10.1002/cyto.a.21111] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/28/2011] [Accepted: 06/30/2011] [Indexed: 11/09/2022]
Abstract
By using imaging spectrophotometry with paired images in the 200- to 280-nm wavelength range, we have directly mapped intracellular nucleic acid and protein distributions across a population of Chinese hamster ovary (CHO-K1) cells. A broadband 100× objective with a numerical aperture of 1.2 NA (glycerin immersion) and a novel laser-induced-plasma point source generated high-contrast images with short (∼100 ms) exposures and a lateral resolution nearing 200 nm that easily resolves internal organelles. In a population of 420 CHO-K1 cells and 477 nuclei, we found a G1 whole-cell nucleic acid peak at 26.6 pg, a nuclear-isolated total nucleic acid peak at 11.4 pg, and, as inferred by RNase treatment, a G1 total DNA mass of 7.4 pg. At the G1 peak, we found a whole-cell protein mass of 95.6 pg, and a nuclear-isolated protein mass of 39.3 pg. An algorithm for protein quantification that senses peptide-bond (220-nm) absorbance was found to have a higher signal-to-noise ratio and to provide more reliable nucleic acid and protein determinations when compared to more classical 280/260-nm algorithms when used for intracellular mass mapping. Using simultaneous imaging with common nuclear stains (Hoechst 33342, Syto-14, and Sytox Orange), we have compared staining patterns to deep-UV images of condensed chromatin and have confirmed bias of these common nuclear stains related to nuclear packaging. The approach allows absolute mass measurements with no special sample preparation or staining. It can be used in conjunction with normal fluorescence microscopy and with relatively modest modification of the microscope.
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Affiliation(s)
- Man C Cheung
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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30
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Blebbistain, a myosin II inhibitor, as a novel strategy to regulate detrusor contractility in a rat model of partial bladder outlet obstruction. PLoS One 2011; 6:e25958. [PMID: 22016792 PMCID: PMC3189232 DOI: 10.1371/journal.pone.0025958] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 09/14/2011] [Indexed: 11/19/2022] Open
Abstract
Partial bladder outlet obstruction (PBOO), a common urologic pathology mostly caused by benign prostatic hyperplasia, can coexist in 40–45% of patients with overactive bladder (OAB) and is associated with detrusor overactivity (DO). PBOO that induces DO results in alteration in bladder myosin II type and isoform composition. Blebbistatin (BLEB) is a myosin II inhibitor we recently demonstrated potently relaxed normal detrusor smooth muscle (SM) and reports suggest varied BLEB efficacy for different SM myosin (SMM) isoforms and/or SMM vs nonmuscle myosin (NMM). We hypothesize BLEB inhibition of myosin II as a novel contraction protein targeted strategy to regulate DO. Using a surgically-induced male rat PBOO model, organ bath contractility, competitive and Real-Time-RT-PCR were performed. It was found that obstructed-bladder weight significantly increased 2.74-fold while in vitro contractility of detrusor to various stimuli was impaired ∼50% along with decreased shortening velocity. Obstruction also altered detrusor spontaneous activities with significantly increased amplitude but depressed frequency. PBOO switched bladder from a phasic-type to a more tonic-type SM. Expression of 5’ myosin heavy chain (MHC) alternatively spliced isoform SM-A (associated with tonic-type SM) increased 3-fold while 3’ MHC SM1 and essential light chain isoform MLC17b also exhibited increased relative expression. Total SMMHC expression was decreased by 25% while the expression of NMM IIB (SMemb) was greatly increased by 4.5-fold. BLEB was found to completely relax detrusor strips from both sham-operated and PBOO rats pre-contracted with KCl, carbachol or electrical field stimulation although sensitivity was slightly decreased (20%) only at lower doses for PBOO. Thus we provide the first thorough characterization of the response of rat bladder myosin to PBOO and demonstrate complete BLEB-induced PBOO bladder SM relaxation. Furthermore, the present study provides valuable evidence that BLEB may be a novel type of potential therapeutic agent for regulation of myogenic and nerve-evoked DO in OAB.
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Boopathi E, Gomes CM, Goldfarb R, John M, Srinivasan VG, Alanzi J, Malkowicz SB, Kathuria H, Zderic SA, Wein AJ, Chacko S. Transcriptional repression of Caveolin-1 (CAV1) gene expression by GATA-6 in bladder smooth muscle hypertrophy in mice and human beings. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 178:2236-51. [PMID: 21514437 DOI: 10.1016/j.ajpath.2011.01.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 12/28/2010] [Accepted: 01/25/2011] [Indexed: 01/08/2023]
Abstract
Hypertrophy occurs in urinary bladder wall smooth muscle (BSM) in men with partial bladder outlet obstruction (PBOO) caused by benign prostatic hyperplasia (BPH) and in animal models of PBOO. Hypertrophied BSM from the rabbit model exhibits down-regulation of caveolin-1, a structural and functional protein of caveolae that function as signaling platforms to mediate interaction between receptor proteins and adaptor and effector molecules to regulate signal generation, amplification, and diversification. Caveolin-1 expression is diminished in PBOO-induced BSM hypertrophy in mice and in men with BPH. The proximal promoter of the human and mouse caveolin-1 (CAV1) gene was characterized, and it was observed that the transcription factor GATA-6 binds this promoter, causing reduced expression of caveolin-1. Furthermore, caveolin-1 expression levels inversely correlate with the abundance of GATA-6 in BSM hypertrophy in mice and human beings. Silencing of GATA6 gene expression up-regulates caveolin-1 expression, whereas overexpression of GATA-6 protein sustains the transcriptional repression of caveolin-1 in bladder smooth muscle cells. Together, these data suggest that GATA-6 acts as a transcriptional repressor of CAV1 gene expression in PBOO-induced BSM hypertrophy in men and mice. GATA-6-induced transcriptional repression represents a new regulatory mechanism of CAV1 gene expression in pathologic BSM, and may serve as a target for new therapy for BPH-induced bladder dysfunction in aging men.
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Affiliation(s)
- Ettickan Boopathi
- Division of Urology, University of Pennsylvania, Glenolden, Pennsylvania, USA
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Chang AY, Sliwoski J, Butler S, Hearn G, Lassmann J, Chacko S, Canning DA, Zderic SA. Calcineurin mediates bladder wall remodeling secondary to partial outlet obstruction. Am J Physiol Renal Physiol 2011; 301:F813-22. [PMID: 21775483 DOI: 10.1152/ajprenal.00586.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We hypothesized that the calcineurin-nuclear factor of activated T-cells (NFAT) pathway is activated following partial bladder outlet obstruction (pBOO), which would allow for pharmacologic treatment to prevent the ensuing bladder wall hypertrophy. Using a model of pBOO in male mice, we were able to demonstrate increased nuclear importation of the transcription factors NFAT and myocyte enhanching factor 2 both of which are under control of calcineurin in both the whole bladder wall as well as the urothelium. We further confirmed that this pathway was activated using transgenic mice containing an NFAT-luciferase reporter construct. Mice were randomized following pBOO to treatment with or without cyclosporine A (CsA), a known inhibitor of calcineurin. The bladder-to-body mass ratio (mg bladder wt/g body wt) of 0.95 ± 0.03 in shams increased to 3.1 ± 0.35 following pBOO, and it dropped back to 1.7 ± 0.22 in the CsA+ group (P < 0.001). Luciferase values (RLU) of 1,130 ± 133 in shams increased to 2,010 ± 474 following pBOO and were suppressed to 562 ± 177 in the CsA+ group (P < 0.05). The myosin heavy chain mRNA (A/B) isoform ratio of 0.07 ± 0.03 in shams increased to 1.04 ± 0.19 following pBOO but it diminished to 0.24 ± 0.1 in the CsA+ group (P < 0.001). In vitro whole organ physiology studies demonstrated improved responses in those bladders from mice treated with CsA. The mRNAs for all four known calcineurin-responsive NFAT isoforms are expressed in the bladder wall, although NFATc(3) and NFATc(4) predominate. Both NFATc3 and NFATc4 are expressed in urothelial as well as smooth muscle cells. We conclude that pBOO activates the calcineurin-NFAT pathway and that CsA treatment decreased bladder hypertrophy, shifted the pattern of myosin isoform mRNA expression back toward that seen in normal controls, and resulted in improved in vitro whole organ performance.
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Affiliation(s)
- Andy Y Chang
- John W. Duckett Jr. Center for Pediatric Urology at The Children's Hospital of Philadelphia 19104, USA
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33
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Chang S, Gomes CM, Hypolite JA, Marx J, Alanzi J, Zderic SA, Malkowicz B, Wein AJ, Chacko S. Detrusor overactivity is associated with downregulation of large-conductance calcium- and voltage-activated potassium channel protein. Am J Physiol Renal Physiol 2010; 298:F1416-23. [PMID: 20392804 DOI: 10.1152/ajprenal.00595.2009] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Large-conductance voltage- and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet obstruction-induced DO is associated with downregulation of BK channels and whether BK channels affect myosin light chain 20 (MLC(20)) phosphorylation in detrusor smooth muscle (DSM). Partial bladder outlet obstruction (PBOO) was surgically induced in male New Zealand White rabbits. The rabbit PBOO model shows decreased voided volumes and increased voiding frequency. DSM from PBOO rabbits also show enhanced spontaneous contractions compared with control. Both BK channel alpha- and beta-subunits were significantly decreased in DSM from PBOO rabbits. Immunostaining shows BKbeta mainly expressed in DSM, and its expression is much less in PBOO DSM compared with control DSM. Furthermore, a translational study was performed to see whether the finding discovered in the animal model can be translated to human patients. The urodynamic study demonstrates several overactive DSM contractions during the urine-filling stage in benign prostatic hyperplasia (BPH) patients with DO, while DSM is very quiet in BPH patients without DO. DSM biopsies revealed significantly less BK channel expression at both mRNA and protein levels. The degree of downregulation of the BK beta-subunit was greater than that of the BK alpha-subunit, and the downregulation of BK was only associated with DO, not BPH. Finally, the small interference (si) RNA-mediated downregulation of the BK beta-subunit was employed to study the effect of BK depletion on MLC(20) phosphorylation. siRNA-mediated BK channel reduction was associated with an increased MLC(20) phosphorylation level in cultured DSM cells. In summary, PBOO-induced DO is associated with downregulation of BK channel expression in the rabbit model, and this finding can be translated to human BPH patients with DO. Furthermore, downregulation of the BK channel may contribute to DO by increasing the basal level of MLC(20) phosphorylation.
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Affiliation(s)
- Shaohua Chang
- Division of Urology, Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Daneshgari F, Liu G, Birder L, Hanna-Mitchell AT, Chacko S. Diabetic bladder dysfunction: current translational knowledge. J Urol 2010; 182:S18-26. [PMID: 19846137 DOI: 10.1016/j.juro.2009.08.070] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Indexed: 02/06/2023]
Abstract
PURPOSE Diabetes mellitus, a metabolic disorder caused by an absolute or relative deficiency of insulin, is a debilitating and costly disease with multiple serious complications. Lower urinary tract complications are among the most common complications of diabetes mellitus. The most common, bothersome lower urinary tract complication of diabetes mellitus is diabetic cystopathy or diabetic bladder dysfunction. We reviewed the current translational knowledge of diabetic bladder dysfunction. MATERIALS AND METHODS We performed a search of the English literature through PubMed. The key words used were diabetes and bladder dysfunction or cystopathy. Our data and perspective are provided for consideration of the future direction of research. RESULTS Despite traditional recognition of diabetic bladder dysfunction as a voiding problem characterized by poor emptying and overflow incontinence, recent clinical and experimental evidence indicate storage problems such as urgency and urge incontinence in diabetes mellitus cases. Recent experimental evidence from studies of diabetic bladder dysfunction in small animal models of diabetes mellitus show a temporal effect on diabetic bladder dysfunction. Early phase diabetes mellitus causes compensated bladder function and the late phase causes decompensated bladder function. The temporal theory could plausibly provide the scientific road map to correlate clinical and experimental findings, and identify the role of mechanisms such as polyuria, hyperglycemia, oxidative stress, autonomic neuropathy and decompensation of the bladder contractile apparatus in the creation of clinical and experimental manifestations of diabetic bladder dysfunction. CONCLUSIONS Diabetic bladder dysfunction includes time dependent manifestations of storage and emptying problems. Identifying mechanistic pathways would lead to the identification of therapeutic intervention.
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Affiliation(s)
- Firouz Daneshgari
- Department of Urology, Case Western Reserve University, Cleveland, Ohio, USA.
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35
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Aydin M, Downing K, Villegas G, Zhang X, Chua R, Melman A, DiSanto ME. The sphingosine-1-phosphate pathway is upregulated in response to partial urethral obstruction in male rats and activates RhoA/Rho-kinase signalling. BJU Int 2010; 106:562-71. [DOI: 10.1111/j.1464-410x.2009.09156.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Bushman W. Etiology, epidemiology, and natural history of benign prostatic hyperplasia. Urol Clin North Am 2010; 36:403-15, v. [PMID: 19942041 DOI: 10.1016/j.ucl.2009.07.003] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Historically, benign prostatic hyperplasia (BPH) has been a major focus of urologic practice and surgery. But a simplistic causal relationship among prostatic enlargement, progressive obstruction, lower urinary tract symptoms, retention, and complications of retention has been challenged by recognition of the incomplete overlap of prostatic enlargement with symptoms and obstruction. The result has been a greater focus on symptoms than prostatic enlargement and a shift from surgery to medical treatment. Therefore, the question can be asked whether BPH per se, the glandular enlargement as it contributes to bladder dysfunction, or hyperplastic enlargement as a biomarker for generalized lower urinary tract dysfunction are concerns. This article addresses these issues.
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Affiliation(s)
- Wade Bushman
- Department of Urology, University of Wisconsin Medical School, K6-562 Clinical Science Center, 600 Highland Avenue, Madison, WI 53792, USA.
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Polyák E, Boopathi E, Mohanan S, Deng M, Zderic SA, Wein AJ, Chacko S. Alterations in caveolin expression and ultrastructure after bladder smooth muscle hypertrophy. J Urol 2009; 182:2497-503. [PMID: 19765744 DOI: 10.1016/j.juro.2009.07.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Indexed: 10/20/2022]
Abstract
PURPOSE Partial bladder outlet obstruction in male rabbits causes detrusor smooth muscle hypertrophy and voiding dysfunction similar to that observed in men with benign prostate hyperplasia. Using this model, we analyzed the protein expression and ultrastructure of caveolae and the intermediate size filament in detrusor smooth muscle following partial bladder outlet obstruction induced hypertrophy. MATERIALS AND METHODS Detrusor smooth muscle sections from bladder body were processed for immunofluorescence and electron microscopy. Western analysis was performed to determine the expression of caveolin isoform-1, 2 and 3, and intermediate size filament proteins. RESULTS Detrusor smooth muscle cells from both normal and hypertrophied bladders contain orderly arrays of thick and thin myofilaments, interspersed with dense bodies. In addition, there was an increase in intermediate size filaments in the hypertrophic detrusor smooth muscle cells. The dense plaques in the inner membrane of hypertrophied detrusor smooth muscle were longer than those of the control. Detrusor smooth muscle from hypertrophied bladder revealed a decreased number of caveolae and a lack of their orderly distribution at the plasma membrane. Western blotting showed decreased expression of caveolin-1, 2 and 3 in hypertrophied detrusor smooth muscle. CONCLUSIONS Caveolae serve as platforms for proteins and receptors that have a role in signal transduction. The decreased number of caveolae and caveolin protein expression in hypertrophied detrusor smooth muscle might contribute to alterations in signal transduction pathways that regulate the downstream effects of agonist induced contraction, including calcium sensitization, observed in obstructed bladder. In addition, the increased number of intermediate size filaments in the hypertrophied detrusor smooth muscle is likely to alter the cytoskeletal structure and affect the cellular transmission of passive and/or active force.
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Affiliation(s)
- Erzsébet Polyák
- Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania 19036, USA
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Chacko S, Chang S, Hypolite J, Disanto M, Wein A. Alteration of contractile and regulatory proteins following partial bladder outlet obstruction. ACTA ACUST UNITED AC 2009:26-36. [PMID: 15545194 DOI: 10.1080/03008880410015147] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This paper reviews the contractility and the expression of contractile and regulatory proteins in the detrusor smooth muscle (DSM) following partial bladder outlet obstruction (PBOO) in rabbits. PBOO was surgically induced by partial ligation of the urethra in adult male New Zealand White rabbits. The force generated by DSM strips from normal and obstructed bladders which showed bladder dysfunction, despite detrusor hypertrophy (decompensated bladder, DB) was measured. The expression of contractile and regulatory proteins was analyzed by reverse transcriptase-polymerase chain reaction and Western blotting. The DSM from obstructed DB revealed an overexpression of SM-A myosin heavy chain isoform (associated with decreased maximum velocity of shortening). DSM from sham-operated rabbits showed phasic contractions, whereas the detrusor from DB was tonic, exhibiting slow development of force, a longer duration of force maintenance, and slow relaxation. Rho-kinase inhibitor Y-27632 enhanced the relaxation of precontracted (with 125 mM KCl) DSM strips from DB. The enhancement of relaxation of DB by Y-27632 was associated with dephosphorylation of myosin light chain. The detrusor from normal bladders expresses predominantly the smooth muscle caldesmon (h-CaD), a thin filament-associated protein. However, the DSM from DB shows an overexpression of l-CaD, the non-muscle isoform of CaD. The l-CaD colocalizes with myosin in the cytoplasmic filaments in myocytes. These results show that the alteration of contractility of the detrusor following PBOO is associated with changes in the expression of proteins that form the contractile apparatus and regulate the actomyosin ATPase activity and contraction.
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Affiliation(s)
- Samuel Chacko
- Department of Pathobiology, University of Pennsylvania, Philadelphia, 19104, USA.
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Alteration of the PKC-mediated signaling pathway for smooth muscle contraction in obstruction-induced hypertrophy of the urinary bladder. J Transl Med 2009; 89:823-32. [PMID: 19381130 PMCID: PMC2702459 DOI: 10.1038/labinvest.2009.38] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Normal urinary bladder function requires contraction and relaxation of the detrusor smooth muscle (DSM). The DSM undergoes compensatory hypertrophy in response to partial bladder outlet obstruction (PBOO) in both men and animal models. Following bladder hypertrophy, the bladder either retains its normal function (compensated) or becomes dysfunctional (decompensated) with increased voiding frequency and decreased void volume. We analyzed the contractile characteristics of DSM in a rabbit model of PBOO. The protein kinase C (PKC) agonist phorbol 12, 13-dibutyrate (PDBu) elicited similar levels of contraction of DSM strips from normal and compensated bladders. However, PDBu-induced contraction decreased significantly in DSM strips from decompensated bladders. The expression and activity of PKC-alpha were also lowest in decompensated bladders. The PKC-specific inhibitor bisindolylmaleimide-1 (Bis) blocked PDBu-induced contraction and PKC activity in all three groups. Moreover, the phosphorylation of the phosphoprotein inhibitor CPI-17 (a 17-kDa PKC-potentiated inhibitory protein of protein phosphatase-1) was diminished in DSM from the decompensated bladder, which would result in less inhibitory potency of CPI-17 on myosin light chain phosphatase activity and contribute to less contractility. Immunostaining revealed the colocalization of PKC and phosphorylated CPI-17 in the DSM and confirmed the decreases of these signaling proteins in the decompensated bladder. Our results show a differential PKC-mediated DSM contraction with corresponding alterations of PKC expression, activity and the phosphorylation of CPI-17. Our finding suggests a significant correlation between bladder function and PKC pathway. An impaired PKC pathway appears to be correlated with severe bladder dysfunction observed in decompensated bladders.
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Hypolite JA, Chang S, LaBelle E, Babu GJ, Periasamy M, Wein AJ, Chacko S. Deletion of SM-B, the high ATPase isoform of myosin, upregulates the PKC-mediated signal transduction pathway in murine urinary bladder smooth muscle. Am J Physiol Renal Physiol 2008; 296:F658-65. [PMID: 19052105 DOI: 10.1152/ajprenal.90221.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Detrusor smooth muscle (DSM) hypertrophy induced by partial bladder outlet obstruction (PBOO) is associated with changes in the NH2-terminal myosin heavy chain isoform from predominantly SM-B to SM-A, alteration in the Ca2+ sensitization pathway, and the contractile characteristics from phasic to tonic in rabbits. We utilized the SM-B knockout (KO) mouse to determine whether a shift from SM-B to SM-A without PBOO is associated with changes in the signal transduction pathway mediated via PKC and CPI-17, which keeps the myosin phosphorylation (MLC20) level high by inhibiting the myosin phosphatase. DSM strips from SM-B KO mice generated more force in response to electrical field stimulation, KCl, carbachol, and phorbol 12,13-dibutyrate than that of age-matched wild-type mice. There was no difference in the ED50 for carbachol but the maximum response was greater for the SM-B KO mice. DSM from SM-B KO mice revealed increased mass and hypertrophy. The KO mice also showed an overexpression of PKC-alpha, increased levels of phospho-CPI-17, and an elevated level of IP3 and DAG upon stimulation with carbachol. Two-dimensional gel electrophoresis revealed an increased level of MLC20 phosphorylation in response to carbachol. Together, these changes may be responsible for the higher level of force generation and maintenance by the DSM from the SM-B KO bladders. In conclusion, our data show that ablation of SM-B is associated with alteration of PKC-mediated signal transduction and CPI-17-mediated Ca2+ sensitization pathway that regulate smooth muscle contraction. Interestingly, similar changes are also present in PBOO-induced DSM compensatory response in the rabbit model in which SM-B is downregulated.
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Affiliation(s)
- Joseph A Hypolite
- Division of Urology and Department of Pathobiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Gur S, Sikka SC, Chandra S, Koka PS, Agrawal KC, Kadowitz PJ, Hellstrom WJ. Alfuzosin attenuates erectile dysfunction in rats with partial bladder outlet obstruction. BJU Int 2008; 102:1651-7. [DOI: 10.1111/j.1464-410x.2008.07914.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ablation of smooth muscle myosin heavy chain SM2 increases smooth muscle contraction and results in postnatal death in mice. Proc Natl Acad Sci U S A 2008; 105:18614-8. [PMID: 19011095 DOI: 10.1073/pnas.0808162105] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The physiological relevance of smooth muscle myosin isoforms SM1 and SM2 has not been understood. In this study we generated a mouse model specifically deficient in SM2 myosin isoform but expressing SM1, using an exon-specific gene targeting strategy. The SM2 homozygous knockout (SM2(-/-)) mice died within 30 days after birth, showing pathologies including segmental distention of alimentary tract, retention of urine in renal pelvis, distension of bladder, and the development of end-stage hydronephrosis. In contrast, the heterozygous (SM2(+/-)) mice appeared normal and reproduced well. In SM2(-/-) bladder smooth muscle the loss of SM2 myosin was accompanied by a concomitant down-regulation of SM1 and a reduced number of thick filaments. However, muscle strips from SM2(-/-) bladder showed increased contraction to K(+) depolarization or in response to M3 receptor agonist Carbachol. An increase of contraction was also observed in SM2(-/-) aorta. However, the SM2(-/-) bladder was associated with unaltered regulatory myosin light chain (MLC20) phosphorylation. Moreover, other contractile proteins, such as alpha-actin and tropomyosin, were not altered in SM2(-/-) bladder. Therefore, the loss of SM2 myosin alone could have induced hypercontractility in smooth muscle, suggesting that distinctly from SM1, SM2 may negatively modulate force development during smooth muscle contraction. Also, because SM2(-/-) mice develop lethal multiorgan dysfunctions, we propose this regulatory property of SM2 is essential for normal contractile activity in postnatal smooth muscle physiology.
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Wolffenbuttel K, de Jong B, Scheepe J, Kok D. Potential for recovery in bladder function after removing a urethral obstruction. Neurourol Urodyn 2008; 27:782-8. [DOI: 10.1002/nau.20588] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Elkelini MS, Aitken K, Bagli DJ, Hassouna MM. Effects of doxycycline on voiding behaviour of rats with bladder outlet obstruction. BJU Int 2008; 103:537-40. [PMID: 18990141 DOI: 10.1111/j.1464-410x.2008.08131.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To examine the voiding behaviour changes in rats with bladder outlet obstruction (BOO) while inhibiting matrix metalloproteinase (MMP) activity with doxycycline, as increased MMP activity may be involved in obstruction-induced bladder hypertrophy. MATERIALS AND METHODS Female Sprague-Dawley were divided into eight groups (three rats in each group): normal control (NC) +/- doxycycline, 3 weeks partial BOO (3WPBOO) +/- doxycycline, 6 weeks PBOO +/- doxycycline, and 3 weeks PBOO followed by 3 weeks de-obstruction (3WOD) +/- doxycycline. All rats received the same food and water and were on the same 12 h dark/light cycle housed in metabolic cages. Treatment groups were given doxycycline 15 mg/kg/day subcutaneously twice daily. The voiding variables measured were average voided volume (AV V) and voiding frequency (VF) in 24 h. After completion of the voiding behaviour studies, the rats were killed and their bladders were excised and weighed. RESULTS The AV Vs were significantly increased (P < 0.05) in all study groups compared with the NC group except for the 3WPBOO-doxycycline and 3WOD-doxycycline groups. The VF was significantly increased (P < 0.05) only in the 3WOD-doxycycline group. The bladder weights were significantly increased after PBOO in all the study groups (P < 0.05), except for the 3WOD group. CONCLUSION These data show that MMP inhibition may affect voiding behaviour during the response to BOO or its relief. This is the first clinical demonstration that interfering with a principal target of bladder muscle wall remodelling may have a direct effect on bladder function.
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Affiliation(s)
- Mohamed S Elkelini
- Surgery/Urology and Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
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Fairbank NJ, Connolly SC, Mackinnon JD, Wehry K, Deng L, Maksym GN. Airway smooth muscle cell tone amplifies contractile function in the presence of chronic cyclic strain. Am J Physiol Lung Cell Mol Physiol 2008; 295:L479-88. [PMID: 18586955 DOI: 10.1152/ajplung.00421.2007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chronic contractile activation, or tone, in asthma coupled with continuous stretching due to breathing may be involved in altering the contractile function of airway smooth muscle (ASM). Previously, we (11) showed that cytoskeletal remodeling and stiffening responses to acute (2 h) localized stresses were modulated by the level of contractile activation of ASM. Here, we investigated if altered contractility in response to chronic mechanical strain was dependent on repeated modulation of contractile tone. Cultured human ASM cells received 5% cyclic (0.3 Hz), predominantly uniaxial strain for 5 days, with once-daily dosing of either sham, forskolin, carbachol, or histamine to alter tone. Stiffness, contractility (KCl), and "relaxability" (forskolin) were then measured as was cell alignment, myosin light-chain phosphorylation (pMLC), and myosin light-chain kinase (MLCK) content. Cells became aligned and baseline stiffness increased with strain, but repeated lowering of tone inhibited both effects (P < 0.05). Strain also reversed a negative tone-modulation dependence of MLCK, observed in static conditions in agreement with previous reports, with strain and tone together increasing both MLCK and pMLC. Furthermore, contractility increased 176% (SE 59) with repeated tone elevation. These findings indicate that with strain, and not without, repeated tone elevation promoted contractile function through changes in cytoskeletal organization and increased contractile protein. The ability of repeated contractile activation to increase contractility, but only with mechanical stretching, suggests a novel mechanism for increased ASM contractility in asthma and for the role of continuous bronchodilator and corticosteroid therapy in reversing airway hyperresponsiveness.
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Affiliation(s)
- Nigel J Fairbank
- School of Biomedical Engineering, Dalhousie Univ., 5981 Univ. Ave., Halifax, Nova Scotia B3H 1W2, Canada
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Wei W, Howard PS, Zderic SA, Macarak EJ. Beta and gamma-sarcoglycans are decreased in the detrusor smooth muscle cells of the partially obstructed rabbit bladder. J Urol 2008; 179:2052-6. [PMID: 18355841 DOI: 10.1016/j.juro.2008.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Indexed: 01/10/2023]
Abstract
PURPOSE We evaluated and quantified the levels of sarcoglycans present in the detrusor muscle layer of rabbits with partial bladder outlet obstruction. MATERIALS AND METHODS Rabbits underwent surgery, as previously described, to partially obstruct the urethra. One, 3, 7 and 14 days after obstruction the detrusor muscle layer was dissected free of the remaining bladder tissue and extracted with detergent to isolate the transmembrane components of the dystroglycan-glycoprotein complex. Several components of the dystroglycan-glycoprotein complex were characterized and quantified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting. RESULTS Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis several bands were noted on gels with a molecular weight (43 and 35 kDa, respectively) corresponding to beta and gamma-sarcoglycan. As obstruction progressed longitudinally, the levels of beta and gamma-sarcoglycan showed progressive decrease at the protein level with beta-sarcoglycan levels recovering at later time points. Bladders with a functional physiology that showed more advanced symptoms of dysfunction had a greater decrease in beta and gamma-sarcoglycan protein. CONCLUSIONS The levels of beta and gamma-sarcoglycan progressively change with obstruction with greater changes occurring in the levels of gamma-sarcoglycan. It is likely that alterations in the dystroglycan-glycoprotein complex are responsible for some of the changes in muscle physiology that occur as a consequence of obstruction.
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Affiliation(s)
- Wenjie Wei
- Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Michel MC, Barendrecht MM. Physiological and pathological regulation of the autonomic control of urinary bladder contractility. Pharmacol Ther 2008; 117:297-312. [DOI: 10.1016/j.pharmthera.2007.12.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2007] [Accepted: 12/04/2007] [Indexed: 01/10/2023]
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Guven A, Kalorin C, Onal B, Whitbeck C, Chichester P, Kogan BA, Levin RM, Mannikarottu A. Novel biomarkers of bladder decompensation after partial bladder obstruction. Neurourol Urodyn 2008; 26:1036-42. [PMID: 17487873 DOI: 10.1002/nau.20433] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AIMS Partial bladder outlet obstruction (PBOO) results in marked contractile, biochemical, and histological alterations in the bladder. Our aim was to determine the time course of progressive PBOO in the rabbit and to find parameters that marked the shift to decompensation. MATERIALS AND METHODS Twenty-four rabbits were subjected to 1, 2, 4, and 8 weeks of PBOO. Sham operated rabbits served as controls. At each time period, cystometry was performed and individual bladder strips were used for contractility studies. Full-thickness sections of bladder body from each rabbit were fixed in formalin and used to determine the vascular density and nerve density. The balance of the bladder body was separated between muscle and mucosa and was analyzed for superoxide dismutase (SOD) and catalase (CAT) activities. RESULTS Bladder weight increased progressively and all contractile responses were reduced significantly over the course of obstruction. Markedly increased bladder weight and very large bladder volumes indicated decompensation. Nerve density was marked decreased in decompensated bladders. Similarly, SOD activity in muscle decreased progressively and was markedly lower in decompensated bladders. Although CAT activity of the muscle increased after 2-4 weeks of obstruction, it decreased markedly in decompensated bladders. CONCLUSION This study shows that prolonged PBOO causes progressive deterioration in the rabbit bladder with decompensation after 8 weeks. Markedly decreased nerve density and severely reduced SOD and CAT activities are associated with the shift from compensated to decompensated function of the bladder. They may be excellent biomarkers of decompensation.
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Affiliation(s)
- Ahmet Guven
- Section of Pediatric Urology, Albany Medical College, Albany, New York, USA
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Lassmann J, Sliwoski J, Chang A, Canning DA, Zderic SA. Deletion of one SERCA2 allele confers protection against bladder wall hypertrophy in a murine model of partial bladder outlet obstruction. Am J Physiol Regul Integr Comp Physiol 2008; 294:R58-65. [DOI: 10.1152/ajpregu.00477.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sarco(endo)plasmic reticulum Ca2+-ATPase2 (SERCA2) is downregulated in cardiac hypertrophy with decompensation. We sought to determine whether mice heterozygous for the SERCA2 allele would develop greater bladder hypertrophy and decompensation than their wild-type littermates following partial bladder outlet obstruction (pBOO). We found that following 4 wk of surgically created pBOO, SERCA2 heterozygous murine bladders showed significantly less hypertrophy, improved in vitro cystometry performance, diminished expression of the slow myosin isoform A analyzed by RT-PCR, a significant drop in nuclear translocation of nuclear factor of activated T cells by EMSA, and decreased cell proliferation within the smooth muscle layer following 5-bromo-2′-deoxyuridine labeling compared with their wild-type littermates. Thus, in contrast to cardiac muscle, deletion of a SERCA2 allele confers protection against bladder hypertrophy in a murine model of pBOO. Compensatory mechanisms in heterozygous mice seem to be related to the calcineurin pathway. Further studies are underway to better define the molecular basis of this observation, which has potential clinical applications.
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Eddinger TJ, Meer DP. Myosin II isoforms in smooth muscle: heterogeneity and function. Am J Physiol Cell Physiol 2007; 293:C493-508. [PMID: 17475667 DOI: 10.1152/ajpcell.00131.2007] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both smooth muscle (SM) and nonmuscle class II myosin molecules are expressed in SM tissues comprising hollow organ systems. Individual SM cells may express one or more of multiple myosin II isoforms that differ in myosin heavy chain (MHC) and myosin light chain (MLC) subunits. Although much has been learned, the expression profiles, organization within contractile filaments, localization within cells, and precise roles in various contractile functions of these different myosin molecules are still not well understood. However, data supporting unique physiological roles for certain isoforms continues to build. Isoform differences located in the S1 head region of the MHC can alter actin binding and rates of ATP hydrolysis. Differences located in the MHC tail can alter the formation, stability, and size of the myosin thick filament. In these distinct ways, both head and tail isoform differences can alter force generation and muscle shortening velocities. The MLCs that are associated with the lever arm of the S1 head can affect the flexibility and range of motion of this domain and possibly the motion of the S2 and motor domains. Phosphorylation of MLC(20) has been associated with conformational changes in the S1 and/or S2 fragments regulating enzymatic activity of the entire myosin molecule. A challenge for the future will be delineation of the physiological significance of the heterogeneous expression of these isoforms in developmental, tissue-specific, and species-specific patterns and or the intra- and intercellular heterogeneity of myosin isoform expression in SM cells of a given organ.
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Affiliation(s)
- Thomas J Eddinger
- Biological Sciences, Marquette University, Milwaukee, WI 53233, USA.
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