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Kisou Y, Inoue T, Nishijima K, Huang M, Yamamoto R, Koizumi A, Nara T, Numakura K, Saito M, Narita S, Satoh S, Habuchi T. Candidate genes involved in the defunctionalization and refunctionalization of the urinary bladder induced by bladder anuria and reperfusion. Neurourol Urodyn 2020; 39:1653-1666. [PMID: 32542707 DOI: 10.1002/nau.24427] [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: 02/13/2020] [Accepted: 06/01/2020] [Indexed: 11/08/2022]
Abstract
AIMS We develop a novel rabbit urinary diversion model of bladder defunctionalization due to bladder anuria followed by refunctionalization due to urine reperfusion to investigate the molecular biological background. To validate the results, we used reverse transcription-polymerase chain reaction (RT-PCR) to analyze human specimens from defunctionalized bladders in patients receiving dialysis before kidney transplantation. METHODS Female rabbits were divided into three groups: control, defunctionalized, and refunctionalized. The bilateral ureters were anastomosed to vagina in the defunctionalized and refunctionalized groups at 0 weeks. In the refunctionalized group, the unilateral ureter was reanastomosed to the bladder at 8 weeks. RESULTS The capacity and compliance of the rabbit bladder in the refunctionalized group were significantly lower than those in the control group at 8 weeks and higher than those in the defunctionalized group at 14 weeks. The significant downregulation of IGFBP2, UPK1B, and CST6 in the defunctionalized group compared with that in the control groups, and the significant downregulation of AGTR2 in the refunctionalized group compared with that in the defunctionalized group in the rabbit bladder-muscle DNA microarray were validated by RT-PCR. Human bladder muscle indicated significant downregulation of UPK1B and CST6 and significant downregulation of IGFBP2 in the defunctionalized group, which is consistent with both rabbit bladder-muscle DNA microarray and rabbit bladder RT-PCR results. CONCLUSIONS The present study using novel model of bladder defunctionalization followed by refunctionalization indicated the consistent downregulation of UPK1B and CST6 in muscle and the consistent downregulation of IGFBP2 in mucosa in process of bladder defunctionalization, which was validated by human specimens.
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Affiliation(s)
- Yusuke Kisou
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takamitsu Inoue
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Kazutoshi Nishijima
- Animal Research Laboratory, Department of Urology, Bioscience Education-Research Support Center, Akita University, Akita, Japan
| | - Minguo Huang
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Ryohei Yamamoto
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Atsushi Koizumi
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Taketoshi Nara
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Kazuyuki Numakura
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Mitsuru Saito
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Shintaro Narita
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
| | - Shigeru Satoh
- Department of Urology, Center for Kidney Disease and Transplantation, Akita University Hospital, Akita, Japan
| | - Tomonori Habuchi
- Department of Urology, Akita University Graduate School of Medicine, Akita, Japan
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2
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Santos CP, Lapi E, Martínez de Villarreal J, Álvaro-Espinosa L, Fernández-Barral A, Barbáchano A, Domínguez O, Laughney AM, Megías D, Muñoz A, Real FX. Urothelial organoids originating from Cd49f high mouse stem cells display Notch-dependent differentiation capacity. Nat Commun 2019; 10:4407. [PMID: 31562298 PMCID: PMC6764959 DOI: 10.1038/s41467-019-12307-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 09/02/2019] [Indexed: 12/29/2022] Open
Abstract
Understanding urothelial stem cell biology and differentiation has been limited by the lack of methods for their unlimited propagation. Here, we establish mouse urothelial organoids that can be maintained uninterruptedly for >1 year. Organoid growth is dependent on EGF and Wnt activators. High CD49f/ITGA6 expression features a subpopulation of organoid-forming cells expressing basal markers. Upon differentiation, multilayered organoids undergo reduced proliferation, decreased cell layer number, urothelial program activation, and acquisition of barrier function. Pharmacological modulation of PPARγ and EGFR promotes differentiation. RNA sequencing highlighted genesets enriched in proliferative organoids (i.e. ribosome) and transcriptional networks involved in differentiation, including expression of Wnt ligands and Notch components. Single-cell RNA sequencing (scRNA-Seq) analysis of the organoids revealed five clusters with distinct gene expression profiles. Together, with the use of γ-secretase inhibitors and scRNA-Seq, confirms that Notch signaling is required for differentiation. Urothelial organoids provide a powerful tool to study cell regeneration and differentiation.
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Affiliation(s)
- Catarina P Santos
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
| | - Eleonora Lapi
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
- CIBERONC, Madrid, Spain
| | - Jaime Martínez de Villarreal
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
- CIBERONC, Madrid, Spain
| | - Laura Álvaro-Espinosa
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
| | - Asunción Fernández-Barral
- CIBERONC, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM and IdiPAZ, 28029, Madrid, Spain
| | - Antonio Barbáchano
- CIBERONC, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM and IdiPAZ, 28029, Madrid, Spain
| | - Orlando Domínguez
- Genomics Unit, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
| | | | - Diego Megías
- Confocal Microscopy Unit, Spanish National Cancer Research Centre-CNIO, Madrid, Spain
| | - Alberto Muñoz
- CIBERONC, Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM and IdiPAZ, 28029, Madrid, Spain
| | - Francisco X Real
- Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre-CNIO, Madrid, Spain.
- CIBERONC, Madrid, Spain.
- Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.
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3
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Chen SF, Lee CL, Kuo HC. Changes in sensory proteins in the bladder urothelium of patients with chronic kidney disease and end-stage renal disease. Low Urin Tract Symptoms 2018; 11:O202-O208. [PMID: 30198096 DOI: 10.1111/luts.12240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/03/2018] [Accepted: 07/17/2018] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Patients with chronic kidney disease (CKD) or end-stage renal disease (ESRD) frequently have lower urinary tract symptoms, such as frequency, urgency, or bladder pain. This study evaluated sensory protein expression in the bladder urothelium of patients with CKD or ESRD. METHODS Twenty-seven patients with ESRD or CKD and urodynamically proven detrusor underactivity (DU; n = 8) or bladder oversensitivity (n = 19) were enrolled in the study. These patients, and 10 controls, underwent cystoscopic biopsies of the urothelium. Western blotting analysis was used to examine the expression of sensory proteins, namely purinergic P2X3 , muscarinic M2 and M3 , and β3 -adrenergic (AR) receptors, as well as inducible (i) and epithelial (e) nitric oxide synthase (NOS), in tissue samples. Expression was compared between CKD or ESRD patients and controls. RESULTS P2X3 receptor expression was lower, whereas β3 -AR was expression higher in the bladder urothelium of the patient group (ESRD and CKD combined) compared with controls. In addition, compared with controls, CKD patients had significantly lower P2X3 receptor expression, whereas ESRD patients had significantly higher M3 receptor expression. There were no significant differences in M2 receptor, eNOS, and iNOS expression between ESRD or CKD patients and controls. Patients with DU had significantly higher M2 and M3 receptor expression. There were no significant differences in the expression of any protein between ESRD and CKD patients, regardless of the presence of bladder pain or anuria. CONCLUSION Significantly decreased P2X3 receptor and increased β3 -AR expression are seen in the bladder urothelium of patients with ESRD or CKD. The expression of these sensory proteins is not associated with decreased bladder capacity or anuria status in patients with ESRD or CKD.
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Affiliation(s)
- Sheng-Fu Chen
- Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
| | - Cheng-Ling Lee
- Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
| | - Hann-Chorng Kuo
- Department of Urology, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
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4
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Urothelial Dysfunction and Chronic Inflammation are Associated With Increased Bladder Sensation in Patients With Chronic Renal Insufficiency. Int Neurourol J 2018; 22:S46-54. [PMID: 29385785 PMCID: PMC5798634 DOI: 10.5213/inj.1832814.407] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 11/29/2017] [Indexed: 11/12/2022] Open
Abstract
Purpose Chronic kidney disease (CKD) or end-stage renal disease (ESRD) patients usually have lower urinary tract symptoms, such as frequency and urgency. Additionally, they frequently suffer from urinary tract infections. This study investigated dysfunction and chronic inflammation of the bladder urothelium in ESRD/CKD patients. Methods This study enrolled 27 patients with CKD (n=13) or ESRD (n=14) for urodynamic studies and bladder biopsies. Patients presented with detrusor underactivity (DU; n=8) or bladder oversensitivity (BO; n=19). Bladder biopsies were performed in these patients and in 20 controls. The bladder mucosa was examined for E-cadherin and zonula occludens-1 (ZO-1) expression, activated mast cell count (through tryptase staining), and urothelial apoptosis (through terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling [TUNEL]). The urodynamic parameters were also compared with variables regarding urothelial dysfunction. Results The bladder mucosa samples of ESRD and CKD patients revealed significantly higher mast cell counts, more urothelial apoptosis, and lower levels of ZO-1 expression than the control samples. E-cadherin expression was significantly reduced in ESRD/CKD patients with DU, but not in ESRD/CKD patients with BO. Increased mast cell and apoptotic cell counts were also associated with ESRD/CKD with BO. Less expression of ZO-1 and E-cadherin was significantly associated with increased bladder sensation and a small bladder capacity. Conclusions Bladder urothelial dysfunction and chronic inflammation were present to a noteworthy extent in patients with ESRD or CKD. Increased inflammation and defective barrier function were more notable in ESRD/CKD bladders with BO than in those with DU. The clinical characteristics of these patients may involve urothelial pathophysiology.
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5
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Gökçe AM, Fındık H, Ata P, Gümrükçü G, Özel L, Gündoğdu K, Yazıcıoğlu B, Titiz MI. Relationship of Urothelial Gene Expressions in Urine-Deprived Bladders of Renal Recipients With Posttransplant Urinary Infections. Transplant Proc 2016; 47:1331-5. [PMID: 26093712 DOI: 10.1016/j.transproceed.2015.04.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE In this study, we analyzed gene expression levels of apoptotic (Fas, FasL, Bcl-2, Bax) and survival (CXCR1, CXCR2, IL-8) signal pathways of the urine-deprived bladder tissues and the relation of urinary tract infections with these pathways. MATERIAL AND METHODS We included 37 patients admitted for renal transplantation between December 2009 and December 2012. Bladder mucosal samples were obtained at the time of transplantation and 6-8 weeks posttransplantation, at the time of ureteral catheter removal. RNA extraction and cDNA synthesis were done using guanidium-thiocyanate and colon filter methods. Expression analysis was studied with quantitative real-time polymerase chain reaction optimized with ROX dye and internal control β-actin. RESULTS According to our findings Fas, FasL, Bcl-2, and Bax expression was higher in urine-deprived bladder samples than those in the posttransplant samples (P < .05). Although Fas, FasL, Bcl-2, and Bax expression levels increased in pretransplant samples, there was an increase in posttransplant bladder samples; however, this increase was not as marked as those of pretransplant samples. IL-8, CXCR1, and CXCR2 expression was decreased at the pretransplant samples and increased in posttransplant bladder samples. CONCLUSIONS We have found an upregulated apoptotic process and decreased survival signals at the urine-deprived bladder tissue. After transplantation, bladder tissue survival parameters were increased, demonstrating the importance of urinary flow for bladder tissue.
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Affiliation(s)
- A M Gökçe
- Department of General Surgery and Transplantation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey
| | - H Fındık
- Department of Molecular Genetics, Haliç University, Istanbul, Turkey
| | - P Ata
- Faculty of Medicine, Department of Medical Genetics, Marmara University, Istanbul, Turkey; Haydarpasa Numune Training and Research Hospital Tissue Typing Laboratory, Istanbul, Turkey.
| | - G Gümrükçü
- Department of General Surgery and Transplantation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey
| | - L Özel
- Department of General Surgery and Transplantation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey
| | - K Gündoğdu
- Department of Molecular Genetics, Haliç University, Istanbul, Turkey
| | - B Yazıcıoğlu
- Department of Molecular Genetics, Haliç University, Istanbul, Turkey
| | - M I Titiz
- Department of General Surgery and Transplantation, Haydarpasa Numune Training and Research Hospital, Uskudar, Istanbul, Turkey
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Subramaniam R, Hinley J, Stahlschmidt J, Southgate J. Tissue engineering potential of urothelial cells from diseased bladders. J Urol 2011; 186:2014-20. [PMID: 21944117 DOI: 10.1016/j.juro.2011.07.031] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Indexed: 12/24/2022]
Abstract
PURPOSE We examined the suitability of urothelium from patients with abnormal bladders for use in surgical reconstruction using a tissue engineering approach that would require autologous urothelium to be expanded by propagation in cell culture. MATERIALS AND METHODS Resection specimens from 8 children (median age 9.8 years) with abnormal bladders (neuropathic in 4, posterior urethral valves in 2, epispadias in 1, nonneurogenic in 1) were collected with informed parental consent during planned urological procedures. Six patients had recurrent urinary tract infections and 7 underwent frequent intermittent catheterization. A representative sample was immunohistologically processed to assess urothelial proliferation and differentiation status, and the remaining 7 cases were processed for urothelial cell culture. Five normal adult urothelial samples were included as controls. RESULTS Immunohistological assessment indicated that 3 of 8 samples lacked urothelial differentiation associated expression of UPK3a or CK20. Four of 7 samples resulted in successful primary culture, with 1 sample lost to underlying infection and 2 not surviving in culture. All 4 cultures grew beyond passage 3 before senescence but all showed reduced proliferation capacity and a compromised ability to form a barrier urothelium compared to controls. CONCLUSIONS While normal human urothelium is highly regenerative and derived cells are highly proliferative in culture, our results with urothelium from abnormal pediatric bladders indicate a reduced capacity for proliferation and differentiation in vitro. This finding may indicate a need to identify alternative cell sources for engineered bladder reconstruction.
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Affiliation(s)
- Ramnath Subramaniam
- Department of Pediatric Urology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
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7
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Oleksiewicz MB, Southgate J, Iversen L, Egerod FL. Rat Urinary Bladder Carcinogenesis by Dual-Acting PPARalpha + gamma Agonists. PPAR Res 2009; 2008:103167. [PMID: 19197366 PMCID: PMC2632771 DOI: 10.1155/2008/103167] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 10/07/2008] [Indexed: 12/25/2022] Open
Abstract
Despite clinical promise, dual-acting activators of PPARalpha and gamma (here termed PPARalpha+gamma agonists) have experienced high attrition rates in preclinical and early clinical development, due to toxicity. In some cases, discontinuation was due to carcinogenic effect in the rat urothelium, the epithelial layer lining the urinary bladder, ureters, and kidney pelvis. Chronic pharmacological activation of PPARalpha is invariably associated with cancer in rats and mice. Chronic pharmacological activation of PPARgamma can in some cases also cause cancer in rats and mice. Urothelial cells coexpress PPARalpha as well as PPARgamma, making it plausible that the urothelial carcinogenicity of PPARalpha+gamma agonists may be caused by receptor-mediated effects (exaggerated pharmacology). Based on previously published mode of action data for the PPARalpha+gamma agonist ragaglitazar, and the available literature about the role of PPARalpha and gamma in rodent carcinogenesis, we propose a mode of action hypothesis for the carcinogenic effect of PPARalpha+gamma agonists in the rat urothelium, which combines receptor-mediated and off-target cytotoxic effects. The proposed mode of action hypothesis is being explored in our laboratories, towards understanding the human relevance of the rat cancer findings, and developing rapid in vitro or short-term in vivo screening approaches to faciliate development of new dual-acting PPAR agonist compounds.
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Affiliation(s)
| | - Jennifer Southgate
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York YO10 5YW, UK
| | - Lars Iversen
- Biopharm Toxicology and Safety Pharmacology, Novo Nordisk A/S, 2760 Maalov, Denmark
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8
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Varley CL, Bacon EJ, Holder JC, Southgate J. FOXA1 and IRF-1 intermediary transcriptional regulators of PPARγ-induced urothelial cytodifferentiation. Cell Death Differ 2008; 16:103-14. [DOI: 10.1038/cdd.2008.116] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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9
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Effects of PPAR agonists on proliferation and differentiation in human urothelium. ACTA ACUST UNITED AC 2008; 60:435-41. [PMID: 18571911 DOI: 10.1016/j.etp.2008.04.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 04/30/2008] [Indexed: 11/20/2022]
Abstract
Systemic treatment of rats with peroxisome proliferator-activated receptor (PPAR) agonists (mainly of dual alpha/gamma activity) has indicated that they may invoke non-genotoxic carcinogenesis in the epithelial lining of the urinary tract (urothelium). Although there is evidence in the male rat to support an indirect effect via a crystaluria-induced urothelial damage response, there is other evidence to indicate a direct signalling effect on the urothelium and hence the full implication for using these drugs in man is unclear. Numerous reports have demonstrated that PPARs are expressed within the urothelium of different species, including man, and from an early developmental stage. We have developed methods to maintain normal human urothelial (NHU) cells in culture, where the cells retain PPAR expression and express a highly proliferative phenotype, mediated via autocrine stimulation of the epidermal growth factor (EGF) receptor. We have shown that specific activation of PPARgamma results in a programme of gene expression changes associated with late/terminal cytodifferentiation, including induction of cytokeratins CK13 and CK20, tight junction-associated claudin 3, and uroplakins UPK1a and UPK2, but this is dependent upon inhibition of the signalling cascade downstream of the EGF receptor. This indicates a subtle balance in the regulation of proliferation and differentiation in urothelium, with PPARgamma agonists promoting differentiation. Our data indicate that human urothelium is a target tissue for PPARgamma signalling, but it has yet to be determined whether dual agonists could have a modulatory effect on the proliferation/differentiation balance.
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10
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Long GG, Reynolds VL, Lopez-Martinez A, Ryan TE, White SL, Eldridge SR. Urothelial carcinogenesis in the urinary bladder of rats treated with naveglitazar, a gamma-dominant PPAR alpha/gamma agonist: lack of evidence for urolithiasis as an inciting event. Toxicol Pathol 2008; 36:218-31. [PMID: 18474944 DOI: 10.1177/0192623307311757] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Naveglitazar, a gamma-dominant peroxisome proliferator-activated receptor (PPAR) alpha/gamma dual agonist, was tested for carcinogenicity in F344 rats in a 2-year study. Changes in urine composition and urothelial morphology were characterized in a companion 18-month investigative study. A significant increase in neoplasms of the bladder occurred only in females of the high-dose group (14/60) in the carcinogenicity study. Trends toward increased cell proliferation in the urothelium were noted in both sexes at all time points evaluated in the 18-month study. Group means for urothelial mitogenesis were increased statistically significantly only in high-dose females at 12 and 18 months. Urothelial hyperplasia occurred in high-dose females at 18 months. Morphologic changes in the urothelium at earlier time points were limited to hypertrophy and decreased immunolabeling of the superficial cells for cytokeratin 20 (a marker of terminal differentiation in urothelial cells) in both males and females. No treatment-related changes in urinary parameters, including urinary sediments, were associated with the occurrence of urothelial proliferation. Urinary pH was unaffected by treatment in both males and females, but expected diurnal changes were demonstrated. Collectively, these data indicate that naveglitazar was associated with hypertrophic and proliferative effects on the urothelium, but a link with changes in urinary parameters was not demonstrated.
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Affiliation(s)
- Gerald G Long
- Lilly Research Laboratories, Greenfield, Indiana 46140, USA. Long_
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11
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Chopra B, Hinley J, Oleksiewicz MB, Southgate J. Trans-Species Comparison of PPAR and RXR Expression by Rat and Human Urothelial Tissues. Toxicol Pathol 2008; 36:485-95. [DOI: 10.1177/0192623308315672] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Because some investigational peroxisome proliferator-activated receptors (PPAR) agonists cause tumors in the lower urinary tract of rats, we compared normal human and rat urothelium in terms of PPAR and retinoid X receptor (RXR) expression and proliferation-associated phenotypes. In situ, few human but most rat urothelial cells were Ki67 positive, indicating fundamental differences in cell cycle control. Rat and human urothelia expressed all 3 PPAR and the RXRα and RXRβ isoforms in a predominantly nuclear localization, indicating that they may be biologically active. However, immunolocalization differences were observed between species. First, whereas PPARα and PPARβ/δ were expressed throughout the human bladder or ureteric urothelium, in the rat urothelium PPARα was primarily, and PPARβ/δ exclusively, restricted to superficial cells. Second, RXRβ was restricted to intermediate and superficial layers of the human urothelium but tended to be absent from the rat superficial cells. Third, PPARγ expression was present throughout the urothelia of both species but was most intense in the superficial human urothelium. Species differences were also observed in the expression of PPAR and RXR isoforms between cultured rat and human urothelial cells and in the smooth muscle. Our findings highlight the unique coexpression of multiple PPAR and RXR isoforms by urothelium and suggest that species differences in PPAR function between rat and human urothelia may be explored in an in vitro setting.
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Affiliation(s)
- Bikramjit Chopra
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
| | - Jennifer Hinley
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
| | | | - Jennifer Southgate
- Jack Birch Unit of Molecular Carcinogenesis, Department of Biology, University of York, York, Y010 5YW, UK
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Jenkins D, Woolf AS. Uroplakins: new molecular players in the biology of urinary tract malformations. Kidney Int 2006; 71:195-200. [PMID: 17183244 DOI: 10.1038/sj.ki.5002053] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The uroplakins (UPs) are a family of proteins which associate with each other and form plaques on the apical surface of the urothelium. These plaques contribute to a permeability barrier, preventing the influx of urine from the urinary tract lumen. Urinary tract malformations associated with human and mouse UP mutations, the human fetal expression patterns of UPs and experiments in Xenopus oocytes are collectively revealing new functions for the UPs, forcing us to view these proteins in a new light. Rather than simply being products of the urothelial differentiation program, they may be a group of proteins central to the process of urinary tract differentiation itself.
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Affiliation(s)
- D Jenkins
- Clinical Genetics Unit, Weatherall Institute of Molecular Medicine, University of Oxford, UK
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13
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Graham E, Chai TC. Dysfunction of bladder urothelium and bladder urothelial cells in interstitial cystitis. Curr Urol Rep 2006; 7:440-6. [PMID: 17052438 DOI: 10.1007/s11934-006-0051-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The human bladder urothelium (BU) and bladder urothelial cells (BUCs) play an important role in the normal functioning of bladder including bladder storage. Current evidence in interstitial cystitis (IC) supports multiple abnormalities in bladder urothelial physiology. These data have come primarily from human studies. The discovery of a novel protein termed the antiproliferative factor (APF) uniquely expressed by IC BUCs is extremely important. APF induces increased permeability of normal BUCs grown in culture. Furthermore, APF regulates expression of other cytokines, including upregulating heparin-binding epidermal growth factor-like growth factor and downregulating epidermal growth factor by BUCs. These cytokine abnormalities were also related to increases in purinergic (adenosine triphosphate) signaling, which could mediate increased bladder sensation. Recent studies of uroplakins, which are specialized proteins expressed only in the apical urothelial cells, suggest that uroplakins play a role in the barrier function of the BU. It is also conceivable that alterations in uroplakins may result in bladder symptoms related to increased permeability or decreased protective function. As the body of knowledge about BU and BUC function increases, novel therapies targeting urothelial cells should become clinically feasible.
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Affiliation(s)
- Emmanuel Graham
- Division of Urology, University of Maryland Medical Center, 22 S. Greene Street, S8D18, Baltimore, MD 21201, USA
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