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Meuser M, Deuper L, Rudat C, Aydoğdu N, Thiesler H, Zarnovican P, Hildebrandt H, Trowe MO, Kispert A. FGFR2 signaling enhances the SHH-BMP4 signaling axis in early ureter development. Development 2022; 149:273983. [DOI: 10.1242/dev.200021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 12/09/2021] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The patterned array of basal, intermediate and superficial cells in the urothelium of the mature ureter arises from uncommitted epithelial progenitors of the distal ureteric bud. Urothelial development requires signaling input from surrounding mesenchymal cells, which, in turn, depend on cues from the epithelial primordium to form a layered fibro-muscular wall. Here, we have identified FGFR2 as a crucial component in this reciprocal signaling crosstalk in the murine ureter. Loss of Fgfr2 in the ureteric epithelium led to reduced proliferation, stratification, intermediate and basal cell differentiation in this tissue, and affected cell survival and smooth muscle cell differentiation in the surrounding mesenchyme. Loss of Fgfr2 impacted negatively on epithelial expression of Shh and its mesenchymal effector gene Bmp4. Activation of SHH or BMP4 signaling largely rescued the cellular defects of mutant ureters in explant cultures. Conversely, inhibition of SHH or BMP signaling in wild-type ureters recapitulated the mutant phenotype in a dose-dependent manner. Our study suggests that FGF signals from the mesenchyme enhance, via epithelial FGFR2, the SHH-BMP4 signaling axis to drive urothelial and mesenchymal development in the early ureter.
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Affiliation(s)
- Max Meuser
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Lena Deuper
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Carsten Rudat
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Nurullah Aydoğdu
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Hauke Thiesler
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Patricia Zarnovican
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Herbert Hildebrandt
- Institute of Clinical Biochemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Mark-Oliver Trowe
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Andreas Kispert
- Institute of Molecular Biology, Medizinische Hochschule Hannover, 30625 Hannover, Germany
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2
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Narla ST, Bushnell DS, Schaefer CM, Nouraie M, Tometich JT, Hand TW, Bates CM. Loss of Fibroblast Growth Factor Receptor 2 (FGFR2) Leads to Defective Bladder Urothelial Regeneration after Cyclophosphamide Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:631-651. [PMID: 33385344 DOI: 10.1016/j.ajpath.2020.12.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/03/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Cyclophosphamide may cause hemorrhagic cystitis and eventually bladder urothelial cancer. Genetic determinants for poor outcomes are unknown. We assessed actions of fibroblast growth factor receptor (FGFR) 2 in urothelium after cyclophosphamide exposure. Conditional urothelial deletion of Fgfr2 (Fgfr2KO) did not affect injury severity or proliferation of keratin 14+ (KRT14+) basal progenitors or other urothelial cells 1 day after cyclophosphamide exposure. Three days after cyclophosphamide exposure, Fgfr2KO urothelium had defective regeneration, fewer cells, larger basal cell bodies and nuclei, paradoxical increases in proliferation markers, and excessive replication stress versus controls. Fgfr2KO mice had evidence of pathologic basal cell endoreplication associated with absent phosphorylated ERK staining and decreased p53 expression versus controls. Mice with conditional deletion of Fgfr2 in urothelium enriched for KRT14+ cells reproduced Fgfr2KO abnormalities after cyclophosphamide exposure. Fgfr2KO urothelium had defects up to 6 months after injury versus controls, including larger basal cells and nuclei, more persistent basal and ectopic lumenal KRT14+ cells, and signs of metaplasia (attenuated E-cadherin staining). Mice missing one allele of Fgfr2 also had (less severe) regeneration defects and basal cell endoreplication 3 days after cyclophosphamide exposure versus controls. Thus, reduced FGFR2/ERK signaling apparently leads to abnormal urothelial repair after cyclophosphamide exposure from pathologic basal cell endoreplication. Patients with genetic variants in FGFR2 or its ligands may have increased risks of hemorrhagic cystitis or urothelial cancer from persistent and ectopic KRT14+ cells.
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Affiliation(s)
- Sridhar T Narla
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Daniel S Bushnell
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Caitlin M Schaefer
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Mehdi Nouraie
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Justin T Tometich
- Mellon Institute for Pediatric Research, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Timothy W Hand
- Mellon Institute for Pediatric Research, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Infectious Disease Section, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania
| | - Carlton M Bates
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Division of Nephrology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania.
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3
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Directed differentiation of human induced pluripotent stem cells into mature stratified bladder urothelium. Sci Rep 2019; 9:10506. [PMID: 31324820 PMCID: PMC6642190 DOI: 10.1038/s41598-019-46848-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 07/05/2019] [Indexed: 02/06/2023] Open
Abstract
For augmentation or reconstruction of urinary bladder after cystectomy, bladder urothelium derived from human induced pluripotent stem cells (hiPSCs) has recently received focus. However, previous studies have only shown the emergence of cells expressing some urothelial markers among derivatives of hiPSCs, and no report has demonstrated the stratified structure, which is a particularly important attribute of the barrier function of mature bladder urothelium. In present study, we developed a method for the directed differentiation of hiPSCs into mature stratified bladder urothelium. The caudal hindgut, from which the bladder urothelium develops, was predominantly induced via the high-dose administration of CHIR99021 during definitive endoderm induction, and this treatment subsequently increased the expressions of uroplakins. Terminal differentiation, characterized by the increased expression of uroplakins, CK13, and CK20, was induced with the combination of Troglitazone + PD153035. FGF10 enhanced the expression of uroplakins and the stratification of the epithelium, and the transwell culture system further enhanced such stratification. Furthermore, the barrier function of our urothelium was demonstrated by a permeability assay using FITC-dextran. According to an immunohistological analysis, the stratified uroplakin II-positive epithelium was observed in the transwells. This method might be useful in the field of regenerative medicine of the bladder.
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4
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Kanai A, Fry C, Ikeda Y, Kullmann FA, Parsons B, Birder L. Implications for bidirectional signaling between afferent nerves and urothelial cells-ICI-RS 2014. Neurourol Urodyn 2016; 35:273-7. [PMID: 26872567 DOI: 10.1002/nau.22839] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 07/06/2015] [Indexed: 11/10/2022]
Abstract
AIMS To present a synopsis of the presentations and discussions from Think Tank I, "Implications for afferent-urothelial bidirectional communication" of the 2014 International Consultation on Incontinence-Research Society (ICI-RS) meeting in Bristol, UK. METHODS The participants presented what is new, currently understood or still unknown on afferent-urothelial signaling mechanisms. New avenues of research and experimental methodologies that are or could be employed were presented and discussed. RESULTS It is clear that afferent-urothelial interactions are integral to the regulation of normal bladder function and that its disruption can have detrimental consequences. The urothelium is capable of releasing numerous signaling factors that can affect sensory neurons innervating the suburothelium. However, the understanding of how factors released from urothelial cells and afferent nerve terminals regulate one another is incomplete. Utilization of techniques such as viruses that genetically encode Ca(2+) sensors, based on calmodulin and green fluorescent protein, has helped to address the cellular mechanisms involved. Additionally, the epithelial-neuronal interactions in the urethra may also play a significant role in lower urinary tract regulation and merit further investigation. CONCLUSION The signaling capabilities of the urothelium and afferent nerves are well documented, yet how these signals are integrated to regulate bladder function is unclear. There is unquestionably a need for expanded methodologies to further our understanding of lower urinary tract sensory mechanisms and their contribution to various pathologies.
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Affiliation(s)
- Anthony Kanai
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Christopher Fry
- Department of Physiology, University of Bristol, Bristol, UK
| | - Youko Ikeda
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Brian Parsons
- Department of Physiology, University of Bristol, Bristol, UK
| | - Lori Birder
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
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5
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Yin SJ, Tang XB, Li FF, Zhang T, Yuan ZW, Wang WL, Bai YZ. Spatiotemporal Expression of Fibroblast Growth Factor 10 in Human Hindgut and Anorectal Development. Cells Tissues Organs 2013; 198:28-34. [DOI: 10.1159/000351472] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2013] [Indexed: 11/19/2022] Open
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6
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Zhang D, Hudson AE, Delostrinos CF, Carmean N, Eastman R, Hicks B, Hurst RE, Bassuk JA. Dual sources of vitronectin in the human lower urinary tract: synthesis by urothelium vs. extravasation from the bloodstream. Am J Physiol Renal Physiol 2010; 300:F475-87. [PMID: 21048021 DOI: 10.1152/ajprenal.00407.2010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Vitronectin (VN), secreted into the bloodstream by liver hepatocytes, is known to anchor epithelial cells to basement membranes through interactions with cell surface integrin receptors. We report here that VN is also synthesized by urothelial cells of urothelium in vivo and in vitro. In situ hybridization, dideoxy sequencing, immunohistochemistry, and ELISA of urothelial cell mRNA, cDNA, tissue, and protein extracts demonstrated that the VN gene is active in vivo and in vitro. The expression of VN by urothelium is hypothesized to constitute one of several pathways that anchor basal cells to an underlying substratum and explains why urothelial cells adhere to glass and propagate under serum-free conditions. Therefore, two sources of VN in the human urinary bladder are recognized: 1) localized synthesis by urothelial cells and 2) extravasation of liver VN through fenestrated capillaries. When human plasma was fractionated by denaturing heparin affinity chromatography, VN was isolated in a biologically active form that supported rapid spreading of urothelial cells in vitro under serum-free conditions. This activity was inhibited by the matricellular protein SPARC via direct binding of VN to SPARC through a Ca(+2)-dependent mechanism. A novel form of VN, isolated from the same heparin affinity chromatography column and designated as the VN(c) chromatomer, also supported cell spreading but failed to interact with SPARC. Therefore, the steady-state balance among urothelial cells, their extracellular milieu, and matricellular proteins constitutes a principal mechanism by which urothelia are anchored to an underlying substrata in the face of constant bladder cycling.
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Affiliation(s)
- Dianzhong Zhang
- Program in Human Urothelial Biology, Center for Tissue and Cell Sciences, Seattle Children's Research Institute, Seattle, WA 98101, USA
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7
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Eastman R, Leaf EM, Zhang D, True LD, Sweet RM, Seidel K, Siebert JR, Grady R, Mitchell ME, Bassuk JA. Fibroblast growth factor-10 signals development of von Brunn's nests in the exstrophic bladder. Am J Physiol Renal Physiol 2010; 299:F1094-110. [PMID: 20719973 PMCID: PMC2980411 DOI: 10.1152/ajprenal.00056.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 08/16/2010] [Indexed: 12/29/2022] Open
Abstract
von Brunn's nests have long been recognized as precursors of benign lesions of the urinary bladder mucosa. We report here that von Brunn's nests are especially prevalent in the exstrophic bladder, a birth defect that predisposes the patient to formation of bladder cancer. Cells of von Brunn's nest were found to coalesce into a stratified, polarized epithelium which surrounds itself with a capsule-like structure rich in types I, III, and IV collagen. Histocytochemical analysis and keratin profiling demonstrated that nested cells exhibited a phenotype similar, but not identical, to that of urothelial cells of transitional epithelium. Immunostaining and in situ hybridization analysis of exstrophic tissue demonstrated that the FGF-10 receptor is synthesized and retained by cells of von Brunn's nest. In contrast, FGF-10 is synthesized and secreted by mesenchymal fibroblasts via a paracrine pathway that targets basal epithelial cells of von Brunn's nests. Small clusters of 10pRp cells, positive for both FGF-10 and its receptor, were observed both proximal to and inside blood vessels in the lamina propria. The collective evidence points to a mechanism where von Brunn's nests develop under the control of the FGF-10 signal transduction system and suggests that 10pRp cells may be the original source of nested cells.
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Affiliation(s)
- Rocky Eastman
- Program in Human Urothelial Biology, Center for Tissue and Cell Sciences, Seattle Children's Research Institute, 1900 9th Ave., Mailstop C9S-5, Seattle, WA 98101, USA
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8
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Vinsonneau C, Girshovich A, M'rad MB, Perez J, Mesnard L, Vandermersch S, Placier S, Letavernier E, Baud L, Haymann JP. Intrarenal urothelium proliferation: an unexpected early event following ischemic injury. Am J Physiol Renal Physiol 2010; 299:F479-86. [PMID: 20591940 DOI: 10.1152/ajprenal.00585.2009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Identification of renal cell progenitors and recognition of the events contributing to cell regeneration following ischemia-reperfusion injury (IRI) are a major challenge. In a mouse model of unilateral renal IRI, we demonstrated that the first cells to proliferate within injured kidneys were urothelial cells expressing the progenitor cell marker cytokeratin 14. A systematic cutting of the injured kidney revealed that these urothelial cells were located in the deep cortex at the corticomedullary junction in the vicinity of lobar vessels. Contrary to multilayered bladder urothelium, these intrarenal urothelial cells located in the upper part of the medulla constitute a monolayered barrier and express among uroplakins only uroplakin III. However, like bladder progenitors, intrarenal urothelial cells proliferated through a FGF receptor-2 (FGFR2)-mediated process. They strongly expressed FGFR2 and proliferated in vivo after recombinant FGF7 administration to control mice. In addition, IRI led to FGFR phosphorylation together with the selective upregulation of FGF7 and FGF2. Conversely, by day 2 following IRI, renal urothelial cell proliferation was significantly inhibited by FGFR2 antisense oligonucleotide administration into an intrarenal urinary space. Of notice, no significant migration of these early dividing urothelial cells was detected in the cortex within 7 days following IRI. Thus our data show that following IRI, proliferation of urothelial cells is mediated by the FGFR2 pathway and precedes tubular cell proliferation, indicating a particular sensitivity of this structure to changes caused by the ischemic process.
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Affiliation(s)
- C Vinsonneau
- INSERM UMRS, Université Pierre et Marie Curie Paris, France
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9
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Omoto Y. Estrogen receptor-alpha signaling in growth of the ventral prostate: comparison of neonatal growth and postcastration regrowth. Endocrinology 2008; 149:4421-7. [PMID: 18535112 DOI: 10.1210/en.2007-1413] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A role for estrogen receptor (ER)-alpha in branching morphogenesis in the ventral prostate (VP) has previously been demonstrated; in the VP of ERalpha(-/-) mice, there are fewer side branches than in wild-type littermates. In the present study, we show that in the postnatal VP, fibroblast growth factor 10 (FGF10) is expressed in wild-type mice but not in ERalpha(-/-) mice, and because branching involves proliferation pathways also used in malignant growth, we investigated whether branching during regrowth of the VP after castration involves ERalpha and FGF10. ERalpha was not detectable in the prostates of sham-operated or castrated mice but was expressed in the prostatic epithelium between d 3 and 5 after testosterone replacement. Blocking either ERalpha or ERbeta with ICI 182,780 had no detectable effects on epithelial cell proliferation during regrowth by testosterone. The ERalpha agonist, propylpyrazoletriol, did not induce regrowth by itself, but exposure to propylpyrazoletriol on d 3-5 of testosterone replacement resulted in cyclin D1-positive cells in the ductal epithelium, invasion of FGF10-positive immune cells in the regrowing prostate, and budding 14 d later. Testosterone replacement alone did not induce cyclin D1, FGF10, or bud formation. These results indicate that stimulation of ERalpha is essential for ductal branching during postnatal prostate growth. During regrowth after castration, there is a window in time when selective stimulation of ERalpha can also induce ductal branching. The FGF10 for this growth comes from the immune system, not from the prostatic mesenchyme.
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Affiliation(s)
- Yoko Omoto
- Department of BioSciences and Nutrition, Karolinska University Hospital, Huddinge, Karolinska Institutet, SE-14186 Huddinge, Sweden.
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10
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Kosman J, Carmean N, Leaf EM, Dyamenahalli K, Bassuk JA. Translocation of fibroblast growth factor-10 and its receptor into nuclei of human urothelial cells. J Cell Biochem 2008; 102:769-85. [PMID: 17471512 DOI: 10.1002/jcb.21330] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fibroblast growth factor-10 (FGF-10), a mitogen for the epithelial cells lining the lower urinary tract, has been identified inside urothelial cells, despite its acknowledged role as an extracellular signaling ligand. Recombinant (r)FGF-10 was determined by fluorescence microscopy optical sectioning to localize strongly to nuclei inside cultured urothelial cells. To clarify the possible role of a nuclear localization signal (NLS) in this translocation, a variant of rFGF-10 was constructed which lacked this sequence. rFGF-10(no NLS) was found in cytoplasm to a far greater degree than rFGF-10, identifying this motif as a possible NLS. Furthermore, this variant displayed poor or non-existent bioactivity compared to the wild-type protein in triggering mitogenesis in quiescent urothelial cells. The presence of rFGF-10(no NLS) in the nucleus suggested that additional interactions were also responsible for the nuclear accumulation of rFGF-10. The FGF-10 receptor was observed in cell nuclei regardless of the presence or concentration of exogenous rFGF-10 ligand. Co-localization studies between rFGF-10 and the FGF-10 receptor revealed a strong intracellular relationship between the two. This co-localization was seen in nuclei for both rFGF-10 and for rFGF-10(no NLS), although the correlation was weaker for rFGF-10(no NLS). These data show that an NLS-like motif of rFGF-10 is a partial determinant of its intracellular distribution and is necessary for its mitogenic activity. These advancements in the understanding of the activity of FGF-10 present an opportunity to engineer the growth factor as a therapeutic agent for the healing of damaged urothelial tissue.
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Affiliation(s)
- Jeffrey Kosman
- Program in Human Urothelial Biology, Seattle Children's Hospital Research Institute, Seattle, Washington, USA
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11
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Hauser PJ, Dozmorov MG, Bane BL, Slobodov G, Culkin DJ, Hurst RE. Abnormal expression of differentiation related proteins and proteoglycan core proteins in the urothelium of patients with interstitial cystitis. J Urol 2007; 179:764-9. [PMID: 18082196 DOI: 10.1016/j.juro.2007.09.022] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Indexed: 11/30/2022]
Abstract
PURPOSE Expression of the proteoglycan core proteins biglycan, decorin, perlecan and syndecan-1, and differentiation related markers of keratins 18 and 20 were examined to determine the origins of the loss of the glycosaminoglycan layer and investigate more fully the altered differentiation of the urothelium in interstitial cystitis. MATERIALS AND METHODS Formalin fixed biopsies from 27 patients with interstitial cystitis and 5 controls were immunohistochemically labeled for the described proteins and scored using a modification of previous scoring for other markers. Inflammation was scored from hematoxylin and eosin stained slides. By combining previous with new data, cluster analysis showed the relationships among the markers and samples. RESULTS Interstitial cystitis specimens clustered into 4 groups, ranging from most biomarkers abnormal to most biomarkers normal, but all clustered separately from normal controls. One group of interstitial cystitis specimens mainly showed aberrant expression of E-cadherin, which might represent an early abnormality. The biomarkers fell into 2 major groupings. One group consisted of chondroitin sulfate, perlecan, biglycan, decorin and the tight junction protein ZO-1. A second cluster consisted of uroplakin, the epithelial marker keratin 18 and 20, and the morphology of the layer. E-cadherin and syndecan-1 showed little relation to the other 2 clusters or to each other. Inflammation correlated moderately with syndecan-1 but to no other marker. CONCLUSIONS Findings strongly suggest abnormal differentiation in the interstitial cystitis urothelium with a loss of barrier function markers and altered differentiation markers being independent and occurring independently of inflammation. Loss of the glycosaminoglycan layer was associated with a loss of biglycan and perlecan on the luminal layer.
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Affiliation(s)
- Paul J Hauser
- Department of Urology, College of Medicine, Oklahoma University Health Sciences Center, Oklahoma City, Oklahoma, USA
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12
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Lendvay TS, Sweet R, Han CH, Soygur T, Cheng JF, Plaire JC, Charleston JS, Charleston LB, Bagai S, Cochrane K, Rubio E, Bassuk JA. Compensatory paracrine mechanisms that define the urothelial response to injury in partial bladder outlet obstruction. Am J Physiol Renal Physiol 2007; 293:F1147-56. [PMID: 17609292 DOI: 10.1152/ajprenal.00006.2007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Diseases and conditions affecting the lower urinary tract are a leading cause of dysfunctional sexual health, incontinence, infection, and kidney failure. The growth, differentiation, and repair of the bladder's epithelial lining are regulated, in part, by fibroblast growth factor (FGF)-7 and -10 via a paracrine cascade originating in the mesenchyme (lamina propria) and targeting the receptor for FGF-7 and -10 within the transitional epithelium (urothelium). The FGF-7 gene is located at the 15q15-q21.1 locus on chromosome 15 and four exons generate a 3.852-kb mRNA. Five duplicated FGF-7 gene sequences that localized to chromosome 9 were predicted not to generate functional protein products, thus validating the use of FGF-7-null mice as an experimental model. Recombinant FGF-7 and -10 induced proliferation of human urothelial cells in vitro and transitional epithelium of wild-type and FGF-7-null mice in vivo. To determine the extent that induction of urothelial cell proliferation during the bladder response to injury is dependent on FGF-7, an animal model of partial bladder outlet obstruction was developed. Unbiased stereology was used to measure the percentage of proliferating urothelial cells between obstructed groups of wild-type and FGF-7-null mice. The stereological analysis indicated that a statistical significant difference did not exist between the two groups, suggesting that FGF-7 is not essential for urothelial cell proliferation in response to partial outlet obstruction. In contrast, a significant increase in FGF-10 expression was observed in the obstructed FGF-7-null group, indicating that the compensatory pathway that functions in this model results in urothelial repair.
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Affiliation(s)
- Thomas S Lendvay
- Program in Human Urothelial Biology, Seattle Children's Hospital Research Institute, Seattle, WA 98105, USA
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13
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Kosman J, Carmean N, Leaf EM, Dyamenahalli K, Bassuk JA. The motif of SPARC that inhibits DNA synthesis is not a nuclear localization signal. J Mol Biol 2007; 371:883-901. [PMID: 17586526 DOI: 10.1016/j.jmb.2007.04.088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Revised: 04/25/2007] [Accepted: 04/27/2007] [Indexed: 11/23/2022]
Abstract
SPARC (secreted protein acidic and rich in cysteine), although primarily known as a secreted, matricellular protein, has also been identified in urothelial cell nuclei. Many biological activities, including inhibition of cell adhesion and repression of DNA synthesis, have been ascribed to SPARC, but the influence of its intracellular localization on each of these activities is unknown. When exposed by epitope retrieval and nuclear matrix unmasking techniques, endogenous SPARC was found to localize strongly to the nuclei and the nuclear matrix of cultured urothelial cells. Live-cell time-lapse imaging revealed that exogenous fluorescently labeled recombinant (r) SPARC was taken up from medium over a 16 h period and accumulated inside cells. Two variants of rSPARC with alterations in its putative nuclear localization signal (NLS) were generated to investigate the existence and effects of the NLS. These variants demonstrated similar biophysical characteristics as the wild-type protein. Visualization by a variety of techniques, including live-cell imaging, deconvolution microscopy, and cell fractionation, all concurred that exogenous rSPARC was not able to localize to cell nuclei, but instead accumulated as perinuclear clusters. Localization of the rSPARC NLS variants was no different than wild-type, arguing against the presence of an active NLS in rSPARC. Imaging experiments showed that only permeabilized, dead cells avidly took up rSPARC into their nuclei. The rSPARC(no NLS) variant proved ineffective at inhibiting DNA synthesis, whereas the rSPARC(strong NLS) variant was a more potent inhibitor of DNA synthesis than was wild-type rSPARC. The motif of SPARC that inhibits the synthesis of urothelial cell DNA is therefore not a nuclear localization signal, but its manipulation holds therapeutic potential to generate a "Super-SPARC" that can quiesce proliferative tissues.
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Affiliation(s)
- Jeffrey Kosman
- Program in Human Urothelial Biology, Seattle Children's Hospital Research Institute, Seattle, WA 98105, USA
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14
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Carmean N, Kosman JW, Leaf EM, Hudson AE, Opheim KE, Bassuk JA. Immortalization of human urothelial cells by human papillomavirus type 16 E6 and E7 genes in a defined serum-free system. Cell Prolif 2007; 40:166-84. [PMID: 17472725 PMCID: PMC6495660 DOI: 10.1111/j.1365-2184.2007.00428.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Accepted: 11/15/2006] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Normal human epithelial cell cultures exhibit a limited (although different between tissues) lifespan in vitro. In previous studies, urothelial cell cultures were immortalized using retroviral transformation with human papillomavirus type 16 E6 and E7 genes, in undefined culture systems containing serum or bovine pituitary extract. OBJECTIVE Due to the variability of results in such systems, we instead developed a procedure for the immortalization of urothelial cells using a defined, serum-free culture system. METHOD AND RESULTS Immortalization through retroviral transformation with human papillomavirus type 16 E6 and E7 was successful, and transformation of urothelial cells conferred an extended over normal lifespan and restored telomerase activity. Transformed cells retained typical morphology and exhibited a similar growth rate, cytokeratin immunoreactivity pattern, and response to growth factors as observed in untransformed cells. Karyotype analysis revealed a gradual accumulation of genetic mutations that are consistent with previously reported mutations in epithelial cells transformed with human papillomavirus type 16 E6 and E7. CONCLUSION The ability to extend the in vitro lifespan of cells holds the potential to reduce the continuous need for tissue samples and to enable complete investigations with one cell line.
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Affiliation(s)
- N Carmean
- Program in Human Urothelial Biology, Seattle Children's Hospital, Seattle, WA 98105, USA
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