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Aksel S, Derpinghaus A, Cao M, Li Y, Cunha G, Baskin L. Neurovascular anatomy of the developing human fetal penis and clitoris. J Anat 2024; 245:35-49. [PMID: 38419143 PMCID: PMC11161816 DOI: 10.1111/joa.14029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/15/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
The human penile and clitoral development begins from a morphologically indifferent genital tubercle. Under the influence of androgen, the genital tubercle forms the penis by forming a tubular urethra within the penile shaft. Without the effect of the androgen, the genital tubercle differentiates into the clitoris, and a lack of formation of the urethra within the clitoris is observed. Even though there are similarities during the development of the glans penis and glans clitoris, the complex canalization occurring along the penile shaft eventually leads to a morphological difference between the penis and clitoris. Based on the morphological differences, the main goal of this study was to define the vascular and neuronal anatomy of the developing penis and clitoris between 8 and 12 weeks of gestation using laser scanning confocal microscopy. Our results demonstrated there is a co-expression of CD31, which is an endothelial cell marker, and PGP9.5, which is a neuronal marker in the penis where the fusion is actively occurring at the ventral shaft. We also identified a unique anatomical structure for the first time, the clitoral ridge, which is a fetal structure running along the clitoral shaft in the vestibular groove. Contrary to previous anatomical findings which indicate that the neurovascular distribution in the developing penis and clitoris is similar, in this study, laser scanning confocal microscopy enabled us to demonstrate finer differences in the neurovascular anatomy between the penis and clitoris.
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Affiliation(s)
- Sena Aksel
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Amber Derpinghaus
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Mei Cao
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Yi Li
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Gerald Cunha
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Laurence Baskin
- Department of UrologyUniversity of CaliforniaSan FranciscoCaliforniaUSA
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2
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Baskin LS. Response to: Letter to Editor - Utility of Genetic Work-Up for 46, XY Patients with Severe Hypospadias. J Pediatr Urol 2022:S1477-5131(22)00583-6. [PMID: 37005195 DOI: 10.1016/j.jpurol.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Affiliation(s)
- Laurence S Baskin
- UCSF Benioff Children's Hospitals, University of California, San Francisco, USA.
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3
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Srivastava P, Tenney J, Lodish M, Slavotinek A, Baskin L. Utility of genetic work-up for 46, XY patients with severe hypospadias. J Pediatr Urol 2022:S1477-5131(22)00537-X. [PMID: 36496321 DOI: 10.1016/j.jpurol.2022.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/25/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Hypospadias is a common congenital abnormality that has been increasing in prevalence over the last decades. Historically, 46, XY patients with severe hypospadias and descended scrotal testes at birth have frequently lacked a genetic diagnosis. Platforms for molecular genetic testing have become more readily available and can offer an insight into underlying genetic causes of severe hypospadias. The goal of this study was to define the anatomical characteristics of severe hypospadias that can accurately define patients with 46, XY severe hypospadias and determine the practical utility of performing molecular genetic testing in this group of patients. METHODS Patients who met the criteria for 46, XY severe hypospadias were offered a molecular genetic work-up in consultation with pediatric genetics. Patients were identified through chart review. Data extracted included karyotype, hypospadias phenotype including stretched penile length at diagnosis, age at genetic diagnosis, molecular genetic testing, pathogenic gene variant(s), gender identity, and clinical course. All patients underwent clinical genetic testing via 46, XY Disorders of Sexual Development (DSD) panels offered by Invitae®, GeneDx®, or Blueprint Genetics®. RESULTS Of the 14 patients that underwent genetic testing, there were 5 previously 27 published and 3 novel pathogenic or likely pathogenic variants in genes associated with 28 46, XY severe hypospadias Table. Pathogenic variants were identified in AR (3), 29 SRD5A2 [1], NR5A1 [2], WT1 [1], and ARTX [1]. Two patients had a variant of unknown significance, one in FREM2 and another in CEP41. Four had negative gene panels. The patient with the WT1 pathogenic variant was subsequently found to have developed a Wilms tumor and the patients with NR5A1 pathogenic variants are now undergoing adrenal insufficiency surveillance. DISCUSSION/CONCLUSION Patients with 46,XY severe hypospadias and descended testes in the scrotum at birth can benefit from molecular genetic testing as their underlying disorders may reveal pathogenic variants that could have potentially life-altering consequences and change surveillance and monitoring.
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Affiliation(s)
- Priya Srivastava
- University of California San Francisco, Division of Pediatric Endocrinology, USA
| | - Jessica Tenney
- University of California San Francisco, Division of Pediatric Genetics and Metabolism, USA
| | - Maya Lodish
- University of California San Francisco, Division of Pediatric Endocrinology, USA
| | - Anna Slavotinek
- University of California San Francisco, Division of Pediatric Genetics and Metabolism, USA
| | - Laurence Baskin
- University of California San Francisco, Division of Pediatric Urology, USA.
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4
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Stancampiano MR, Suzuki K, O'Toole S, Russo G, Yamada G, Faisal Ahmed S. Congenital Micropenis: Etiology And Management. J Endocr Soc 2022; 6:bvab172. [PMID: 35036822 PMCID: PMC8754418 DOI: 10.1210/jendso/bvab172] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 01/23/2023] Open
Abstract
In the newborn, penile length is determined by a number of androgen dependent and independent factors. The current literature suggests that there are interracial differences in stretched penile length in the newborn and although congenital micropenis should be defined as a stretched penile length of less than 2.5 SDS of the mean for the corresponding population and gestation, a pragmatic approach would be to evaluate all boys with a stretched penile length below 2 cm, as congenital micropenis can be a marker for a wide range of endocrine conditions. However, it remains unclear as to whether the state of micropenis, itself, is associated with any long-term consequences. There is a lack of systematic studies comparing the impact of different therapeutic options on long-term outcomes, in terms of genital appearance, quality of life, and sexual satisfaction. To date, research has been hampered by a small sample size and inclusion of a wide range of heterogeneous diagnoses; for these reasons, condition-specific outcomes have been difficult to compare between studies. Lastly, there is a need for a greater collaborative effort in collecting standardized data so that all real-world or experimental interventions performed at an early age can be studied systematically into adulthood.
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Affiliation(s)
| | - Kentaro Suzuki
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama 641-8509, Japan
| | - Stuart O'Toole
- Department of Paediatric Surgery and Urology, Royal Hospital for Children, Glasgow G51 4TF, UK
| | - Gianni Russo
- Department of Pediatrics, Endocrine Unit, Scientific Institute San Raffaele, Milan 20132, Italy
| | - Gen Yamada
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Wakayama 641-8509, Japan
| | - Syed Faisal Ahmed
- Developmental Endocrinology Research Group, University of Glasgow, Glasgow G51 4TF, UK
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Maurizi E, Adamo D, Magrelli FM, Galaverni G, Attico E, Merra A, Maffezzoni MBR, Losi L, Genna VG, Sceberras V, Pellegrini G. Regenerative Medicine of Epithelia: Lessons From the Past and Future Goals. Front Bioeng Biotechnol 2021; 9:652214. [PMID: 33842447 PMCID: PMC8026866 DOI: 10.3389/fbioe.2021.652214] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/23/2021] [Indexed: 12/13/2022] Open
Abstract
This article explores examples of successful and unsuccessful regenerative medicine on human epithelia. To evaluate the applications of the first regenerated tissues, the analysis of the past successes and failures addresses some pending issues and lay the groundwork for developing new therapies. Research should still be encouraged to fill the gap between pathologies, clinical applications and what regenerative medicine can attain with current knowledge.
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Affiliation(s)
| | - Davide Adamo
- Interdepartmental Centre for Regenerative Medicine “Stefano Ferrari”, University of Modena and Reggio Emilia, Modena, Italy
| | | | - Giulia Galaverni
- Interdepartmental Centre for Regenerative Medicine “Stefano Ferrari”, University of Modena and Reggio Emilia, Modena, Italy
| | - Eustachio Attico
- Interdepartmental Centre for Regenerative Medicine “Stefano Ferrari”, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | - Lorena Losi
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | - Graziella Pellegrini
- Holostem Terapie Avanzate S.r.l., Modena, Italy
- Interdepartmental Centre for Regenerative Medicine “Stefano Ferrari”, University of Modena and Reggio Emilia, Modena, Italy
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6
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Baskin LS. New Insights into Hypospadias: Next-generation Sequencing Reveals Potential Genetic Factors in Male Urethral Development. Eur Urol 2021; 79:516-518. [PMID: 33483178 DOI: 10.1016/j.eururo.2021.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 01/06/2021] [Indexed: 02/05/2023]
Affiliation(s)
- Laurence S Baskin
- Pediatric Urology, UCSF Benioff Children's Hospitals, University of California-San Francisco, San Francisco, CA, USA.
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7
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Stadler HS, Peters CA, Sturm RM, Baker LA, Best CJM, Bird VY, Geller F, Hoshizaki DK, Knudsen TB, Norton JM, Romao RLP, Cohn MJ. Meeting report on the NIDDK/AUA Workshop on Congenital Anomalies of External Genitalia: challenges and opportunities for translational research. J Pediatr Urol 2020; 16:791-804. [PMID: 33097421 PMCID: PMC7885182 DOI: 10.1016/j.jpurol.2020.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 09/10/2020] [Accepted: 09/13/2020] [Indexed: 01/02/2023]
Abstract
Congenital anomalies of the external genitalia (CAEG) are a prevalent and serious public health concern with lifelong impacts on the urinary function, sexual health, fertility, tumor development, and psychosocial wellbeing of affected individuals. Complications of treatment are frequent, and data reflecting long-term outcomes in adulthood are limited. To identify a path forward to improve treatments and realize the possibility of preventing CAEG, the National Institute of Diabetes and Digestive and Kidney Diseases and the American Urological Association convened researchers from a range of disciplines to coordinate research efforts to fully understand the different etiologies of these common conditions, subsequent variation in clinical phenotypes, and best practices for long term surgical success. Meeting participants concluded that a central data hub for clinical evaluations, including collection of DNA samples from patients and their parents, and short interviews to determine familial penetrance (small pedigrees), would accelerate research in this field. Such a centralized datahub will advance efforts to develop detailed multi-dimensional phenotyping and will enable access to genome sequence analyses and associated metadata to define the genetic bases for these conditions. Inclusion of tissue samples and integration of clinical studies with basic research using human cells and animal models will advance efforts to identify the developmental mechanisms that are disrupted during development and will add cellular and molecular granularity to phenotyping CAEG. While the discussion focuses heavily on hypospadias, this can be seen as a potential template for other conditions in the realm of CAEG, including cryptorchidism or the exstrophy-epispadias complex. Taken together with long-term clinical follow-up, these data could inform surgical choices and improve likelihood for long-term success.
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Affiliation(s)
- H Scott Stadler
- Department of Skeletal Biology, Shriners Hospital for Children, 3101 SW Sam Jackson Park Road, Portland, OR, Oregon Health & Science University, Department of Orthopaedics and Rehabilitation, Portland, 97239, OR, USA.
| | - Craig A Peters
- Department of Urology, University of Texas Southwestern, 5323 Harry Hines Blvd., Dallas, 75390-9110, TX, USA; Pediatric Urology, Children's Health System Texas, University of Texas Southwestern, Dallas, 75390, TX, USA.
| | - Renea M Sturm
- Department of Urology, Division of Pediatric Urology, University of California Los Angeles, 200 Medical Plaza #170, Los Angeles, 90095, CA, USA
| | - Linda A Baker
- Department of Urology, University of Texas Southwestern, 5323 Harry Hines Blvd., Dallas, 75390-9110, TX, USA
| | - Carolyn J M Best
- American Urological Association, 1000 Corporate Boulevard, Linthicum, 21090, MD, USA
| | - Victoria Y Bird
- Department of Urology, University of Florida, Gainesville, 32610, FL, USA; National Medical Association and Research Group, 5745 SW 75th Street, #507, Gainesville, 32608, FL, USA
| | - Frank Geller
- Department of Epidemiology Research, Statens Serum Institut, 5 Artillerivej, Copenhagen S, DK-2300, Denmark
| | - Deborah K Hoshizaki
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6707 Democracy Boulevard, Bethesda, 20892, MD, USA
| | - Thomas B Knudsen
- US Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Research Triangle Park, 27711, NC, USA
| | - Jenna M Norton
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6707 Democracy Boulevard, Bethesda, 20892, MD, USA
| | - Rodrigo L P Romao
- Departments of Surgery and Urology, IWK Health Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Martin J Cohn
- Department of Molecular Genetics and Microbiology, Department of Biology, And UF Genetics Institute, University of Florida, PO Box 103610, Gainesville, 32610, FL, USA.
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8
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Baskin L, Sinclair A, Derpinghaus A, Cao M, Li Y, Overland M, Aksel S, Cunha GR. Estrogens and development of the mouse and human external genitalia. Differentiation 2020; 118:82-106. [PMID: 33092894 DOI: 10.1016/j.diff.2020.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 09/18/2020] [Indexed: 01/02/2023]
Abstract
The Jost hypothesis states that androgens are necessary for normal development of the male external genitalia. In this review, we explore the complementary hypothesis that estrogens can elicit abnormal development of male external genitalia. Herein, we review available data in both humans and mice on the deleterious effects of estrogen on external genitalia development, especially during the "window of susceptibility" to exogenous estrogens. The male and female developing external genitalia in both the human and mouse express ESR1 and ESR2, along with the androgen receptor (AR). Human clinical data suggests that exogenous estrogens can adversely affect normal penile and urethral development, resulting in hypospadias. Experimental mouse data also strongly supports the idea that exogenous estrogens cause penile and urethral defects. Despite key differences, estrogen-induced hypospadias in the mouse displays certain morphogenetic homologies to human hypospadias, including disruption of urethral fusion and preputial abnormalities. Timing of estrogenic exposure, or the "window of susceptibility," is an important consideration when examining malformations of the external genitalia in both humans and mice. In addition to a review of normal human and mouse external genital development, this article aims to review the present data on the role of estrogens in normal and abnormal development of the mouse and human internal and external genitalia. Based on the current literature for both species, we conclude that estrogen-dependent processes may play a role in abnormal genital development.
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Affiliation(s)
- Laurence Baskin
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA.
| | - Adriane Sinclair
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Amber Derpinghaus
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Mei Cao
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Yi Li
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Maya Overland
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Sena Aksel
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
| | - Gerald R Cunha
- University of California, San Francisco, Division of Pediatric Urology, Department of Urology, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA, 94158, USA
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9
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Baskin LS. EDITORIAL COMMENT. Urology 2020; 144:192-193. [DOI: 10.1016/j.urology.2020.04.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Baskin L, Cao M, Sinclair A, Li Y, Overland M, Isaacson D, Cunha GR. Androgen and estrogen receptor expression in the developing human penis and clitoris. Differentiation 2020; 111:41-59. [PMID: 31655443 PMCID: PMC6926156 DOI: 10.1016/j.diff.2019.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/28/2019] [Accepted: 08/28/2019] [Indexed: 12/21/2022]
Abstract
To better understand how the human fetal penis and clitoris grows and remodels, we undertook an investigation to define active areas of cellular proliferation and programmed cell death spatially and temporally during development of human fetal external genitalia from the indifferent stage (8 weeks) to 18 weeks of gestation. Fifty normal human fetal penile and clitoral specimens were examined using macroscopic imaging, scanning electron microscopy and immunohistochemical localization for the cellular proliferation and apoptotic markers, Ki67 and Caspase-3. A number of hot spots of cellular proliferation characterized by Ki67 localization are present in the penis and clitoris especially early in development, most notably in the corporal body, glans, remodeling glanular urethra, the urethral plate, the roof of the urethral groove and the fully formed penile urethra. The 12-fold increase in penile length over 10 weeks of growth from 8 to 18 weeks of gestation based on Ki67 labelling appears to be driven by cellular proliferation in the corporal body and glans. Throughout all ages in both the developing penis and clitoris Ki67 labeling was consistently elevated in the ventral epidermis and ventral mesenchyme relative to the dorsal counterparts. This finding is consistent with the intense morphogenetic activity/remodeling in the ventral half of the genital tubercle in both sexes involving formation of the urethral/vestibular plates, canalization of the urethral/vestibular plates and fusion of the urethral folds to form the penile urethra. Areas of reduced or absent Ki67 staining include the urethral fold epithelium that fuses to form the penile tubular urethra. In contrast, the urethral fold mesenchyme is positive for Ki67. Apoptosis was rarely noted in the developing penis and clitoris; the only area of minimal Caspase-3 localization was in the epithelium of the ventral epithelial glanular channel remodeling.
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Affiliation(s)
- Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA.
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Yi Li
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Maya Overland
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Dylan Isaacson
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
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11
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Cunha GR, Liu G, Sinclair A, Cao M, Glickman S, Cooke PS, Baskin L. Androgen-independent events in penile development in humans and animals. Differentiation 2020; 111:98-114. [DOI: 10.1016/j.diff.2019.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 01/28/2023]
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12
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Baskin L, Derpinghaus A, Cao M, Sinclair A, Li Y, Overland M, Cunha GR. Hot spots in fetal human penile and clitoral development. Differentiation 2019; 112:27-38. [PMID: 31874420 DOI: 10.1016/j.diff.2019.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 10/28/2019] [Accepted: 11/11/2019] [Indexed: 11/29/2022]
Abstract
To better understand how the human fetal penis and clitoris grows and remodels, we undertook an investigation to define active areas of cellular proliferation and programmed cell death spatially and temporally during development of human fetal external genitalia from the indifferent stage (8 weeks) to 18 weeks of gestation. Fifty normal human fetal penile and clitoral specimens were examined using macroscopic imaging, scanning electron microscopy and immunohistochemical localization for the cellular proliferation and apoptotic markers, Ki67 and Caspase-3, respectively. A number of hot spots of cellular proliferation characterized by Ki67 localization are present in the penis and clitoris especially early in development, most notably in the corporal body, glans, remodeling glanular urethra, the urethral plate, the roof of the urethral groove and the fully formed penile urethra. The 12-fold increase in penile length over 10 weeks of growth from 8 to 18 weeks of gestation based on Ki67 labelling appears to be driven by cellular proliferation in the corporal body and glans. Throughout all ages in both the developing penis and clitoris Ki67 labeling was consistently elevated in the ventral epidermis and ventral mesenchyme relative to the dorsal counterparts. This finding is consistent with the intense morphogenetic activity/remodeling in the ventral half of the genital tubercle in both sexes involving formation of the urethral/vestibular plates, canalization of the urethral/vestibular plates and fusion of the urethral folds to form the penile urethra. Areas of reduced or absent Ki67 staining include the urethral fold epithelium that fuses to form the penile tubular urethra. In contrast, the urethral fold mesenchyme is positive for Ki67. Apoptosis was rarely noted in the developing penis and clitoris; the only area of minimal Caspase-3 localization was in the epithelium of the ventral epithelial glanular channel remodeling.
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Affiliation(s)
- Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA.
| | - Amber Derpinghaus
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Yi Li
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Maya Overland
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
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Isaacson D, McCreedy D, Calvert M, Shen J, Sinclair A, Cao M, Li Y, McDevitt T, Cunha G, Baskin L. Imaging the developing human external and internal urogenital organs with light sheet fluorescence microscopy. Differentiation 2019; 111:12-21. [PMID: 31634681 DOI: 10.1016/j.diff.2019.09.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 10/25/2022]
Abstract
Technological advances in three-dimensional (3D) reconstruction techniques have previously enabled paradigm shifts in our understanding of human embryonic and fetal development. Light sheet fluorescence microscopy (LSFM) is a recently-developed technique that uses thin planes of light to optically section whole-mount cleared and immunolabeled biologic specimens. The advent of commercially-available light sheet microscopes has facilitated a new generation of research into protein localization and tissue dynamics at extremely high resolution. Our group has applied LSFM to study developing human fetal external genitalia, internal genitalia and kidneys. This review describes LSFM and presents our group's technique for preparing, clearing, immunostaining and imaging human fetal urogenital specimens. We then present light sheet images and videos of each element of the developing human urogenital system. To the extent of our knowledge, the work conducted by our laboratory represents the first description of a method for performing LSFM on the full human urogenital system during the embryonic and fetal periods.
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Affiliation(s)
- Dylan Isaacson
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Dylan McCreedy
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Meredith Calvert
- Histology and Light Microscopy Core, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Joel Shen
- CytomX Therapeutics, Inc. South San Francisco, CA, USA
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Yi Li
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Todd McDevitt
- Department of Bioengineering and Therapeutic Sciences, J. David Gladstone Institutes, San Francisco, CA, USA; Institute of Cardiovascular Disease, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Gerald Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA
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Isaacson D, Shen J, Overland M, Li Y, Sinclair A, Cao M, McCreedy D, Calvert M, McDevitt T, Cunha GR, Baskin L. Three-dimensional imaging of the developing human fetal urogenital-genital tract: Indifferent stage to male and female differentiation. Differentiation 2018; 103:14-23. [PMID: 30262218 DOI: 10.1016/j.diff.2018.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/30/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
Recent studies in our lab have utilized three imaging techniques to visualize the developing human fetal urogenital tract in three dimensions: optical projection tomography, scanning electron microscopy and lightsheet fluorescence microscopy. We have applied these technologies to examine changes in morphology and differential gene expression in developing human external genital specimens from the ambisexual stage (<9 weeks fetal age) to well-differentiated male and female organs (>13 weeks fetal age). This work outlines the history and function of each of these three imaging modalities, our methods to prepare specimens for each and the novel findings we have produced thus far. We believe the images in this paper of human fetal urogenital organs produced using lightsheet fluorescence microscopy are the first published to date.
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Affiliation(s)
- Dylan Isaacson
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Joel Shen
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Maya Overland
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Yi Li
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | | | - Meredith Calvert
- J. David Gladstone Institutes, San Francisco, CA, USA; Histology and Light Microscopy Core, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Todd McDevitt
- J. David Gladstone Institutes, San Francisco, CA, USA
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, 550 16th St, 5th Floor, Mission Hall Pediatric Urology, San Francisco, CA 94158, USA.
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Shen J, Cunha GR, Sinclair A, Cao M, Isaacson D, Baskin L. Macroscopic whole-mounts of the developing human fetal urogenital-genital tract: Indifferent stage to male and female differentiation. Differentiation 2018; 103:5-13. [PMID: 30245193 PMCID: PMC6234077 DOI: 10.1016/j.diff.2018.08.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 08/21/2018] [Indexed: 12/22/2022]
Abstract
We present a detailed review of fetal development of the male and female human urogenital tract from 8 to 22 weeks gestation at the macroscopic and morphometric levels. Human fetal specimens were sexed based on macroscopic identification of fetal testes or ovaries, Wolffian or Müllerian structures and the presence of the SRY gene in the specimens at or near the indifferent stage (8-9 weeks). Specimens were photographed using a dissecting microscope with transmitted and reflected light. Morphometric measurements were taken of each urogenital organ. During this time period, development of the male and female urogenital tracts proceeded from the indifferent stage to differentiated organs. The kidneys, ureters, and bladder developed identically, irrespective of sex with the same physical dimensions and morphologic appearance. The penis, prostate and testis developed in males and the clitoris, uterus and ovary in females. Androgen-dependent growth certainly influenced size and morphology of the penile urethra and prostate, however, androgen-independent growth also accounted for substantial growth in the fetal urogenital tract including the clitoris.
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Affiliation(s)
- Joel Shen
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Dylan Isaacson
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States.
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Shen J, Isaacson D, Cao M, Sinclair A, Cunha GR, Baskin L. Immunohistochemical expression analysis of the human fetal lower urogenital tract. Differentiation 2018; 103:100-119. [PMID: 30287094 PMCID: PMC6589035 DOI: 10.1016/j.diff.2018.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 12/15/2022]
Abstract
We have studied the ontogeny of the developing human male and female urogenital tracts from 9 weeks (indifferent stage) to 16 weeks (advanced sex differentiation) of gestation by immunohistochemistry on mid-sagittal sections. Sixteen human fetal pelvises were serial sectioned in the sagittal plane and stained with antibodies to epithelial, muscle, nerve, proliferation and hormone receptor markers. Key findings are: (1) The corpus cavernosum in males and females extends into the glans penis and clitoris, respectively, during the ambisexual stage (9 weeks) and thus appears to be an androgen-independent event. (2) The entire human male (and female) urethra is endodermal in origin based on the presence of FOXA1, KRT 7, uroplakin, and the absence of KRT10 staining. The endoderm of the urethra interfaces with ectodermal epidermis at the site of the urethral meatus. (3) The surface epithelium of the verumontanum is endodermal in origin (FOXA1-positive) with a possible contribution of Pax2-positive epithelial cells implying additional input from the Wolffian duct epithelium. (4) Prostatic ducts arise from the endodermal (FOXA1-positive) urogenital sinus epithelium near the verumontanum. (5) Immunohistochemical staining of mid-sagittal and para-sagittal sections revealed the external anal sphincter, levator ani, bulbospongiosus muscle and the anatomic relationships between these developing skeletal muscles and organs of the male and female reproductive tracts. Future studies of normal human developmental anatomy will lay the foundation for understanding congenital anomalies of the lower urogenital tract.
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Affiliation(s)
- Joel Shen
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Dylan Isaacson
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, United States; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, United States.
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Liu X, Liu G, Shen J, Yue A, Isaacson D, Sinclair A, Cao M, Liaw A, Cunha GR, Baskin L. Human glans and preputial development. Differentiation 2018; 103:86-99. [PMID: 30245194 PMCID: PMC6234068 DOI: 10.1016/j.diff.2018.08.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/21/2018] [Accepted: 08/21/2018] [Indexed: 01/30/2023]
Abstract
The urethra within the human penile shaft develops via (1) an "Opening Zipper" that facilitates distal canalization of the solid urethral plate to form a wide urethral groove and (2) a "Closing Zipper" that facilitates fusion of the epithelial surfaces of the urethral folds. Herein, we extend our knowledge by describing formation of the human urethra within the glans penis as well as development of the prepuce. Forty-eight normal human fetal penile specimens were examined using scanning electron microscopy and optical projection tomography. Serial histologic sections were evaluated for morphology and immunohistochemical localization for epithelial differentiation markers: Cytokeratins 6, 7, 10, FoxA1, uroplakin and the androgen receptor. As the closing zipper completes fusion of the urethral folds within the penile shaft to form a tubular urethra (~ 13 weeks), canalization of the urethral plate continues in proximal to distal fashion into the glans penis to directly form the urethra within the glans without forming an open urethral groove. Initially, the urethral plate is attached ventrally to the epidermis via an epithelial seam, which is remodeled and eliminated, thus establishing mesenchymal confluence ventral to the glanular urethra. The morphogenetic remodeling involves the strategic expression of cytokeratin 7, FoxA1 and uroplakin in endodermal epithelial cells as the tubular glanular urethra forms. The most ventral epithelial cells of the urethral plate are pinched off from the glanular urethra and are reabsorbed into the epidermis ultimately losing expression of their markers, a process undoubtedly regulated by androgens. The prepuce initially forms on the dorsal aspect of the glans at approximately 12 weeks of gestation. After sequential proximal to distal remodeling of the ventral urethral plate along the ventral aspect of glans, the prepuce of epidermal origin fuses in the ventral midline.
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Baskin L, Shen J, Sinclair A, Cao M, Liu X, Liu G, Isaacson D, Overland M, Li Y, Cunha GR. Development of the human penis and clitoris. Differentiation 2018; 103:74-85. [PMID: 30249413 DOI: 10.1016/j.diff.2018.08.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/21/2018] [Accepted: 08/21/2018] [Indexed: 12/17/2022]
Abstract
The human penis and clitoris develop from the ambisexual genital tubercle. To compare and contrast the development of human penis and clitoris, we used macroscopic photography, optical projection tomography, light sheet microscopy, scanning electron microscopy, histology and immunohistochemistry. The human genital tubercle differentiates into a penis under the influence of androgens forming a tubular urethra that develops by canalization of the urethral plate to form a wide diamond-shaped urethral groove (opening zipper) whose edges (urethral folds) fuse in the midline (closing zipper). In contrast, in females, without the influence of androgens, the vestibular plate (homologue of the urethral plate) undergoes canalization to form a wide vestibular groove whose edges (vestibular folds) remain unfused, ultimately forming the labia minora defining the vaginal vestibule. The neurovascular anatomy is similar in both the developing human penis and clitoris and is the key to successful surgical reconstructions.
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Liu G, Liu X, Shen J, Sinclair A, Baskin L, Cunha GR. Contrasting mechanisms of penile urethral formation in mouse and human. Differentiation 2018; 101:46-64. [PMID: 29859371 DOI: 10.1016/j.diff.2018.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 11/27/2022]
Abstract
This paper addresses the developmental mechanisms of formation of the mouse and human penile urethra and the possibility that two disparate mechanisms are at play. It has been suggested that the entire penile urethra of the mouse forms via direct canalization of the endodermal urethral plate. While this mechanism surely accounts for development of the proximal portion of the mouse penile urethra, we suggest that the distal portion of the mouse penile urethra forms via a series of epithelial fusion events. Through review of the recent literature in combination with new data, it is unlikely that the entire mouse urethra is formed from the endodermal urethral plate due in part to the fact that from E14 onward the urethral plate is not present in the distal aspect of the genital tubercle. Formation of the distal portion of the mouse urethra receives substantial contribution from the preputial swellings that form the preputial-urethral groove and subsequently the preputial-urethral canal, the later of which is subdivided by a fusion event to form the distal portion of the mouse penile urethra. Examination of human penile development also reveals comparable dual morphogenetic mechanisms. However, in the case of human, direct canalization of the urethral plate occurs in the glans, while fusion events are involved in formation of the urethra within the penile shaft, a pattern exactly opposite to that of the mouse. The highest incidence of hypospadias in humans occurs at the junction of these two different developmental mechanisms. The relevance of the mouse as a model of human hypospadias is discussed.
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Affiliation(s)
- Ge Liu
- Department of Pediatric Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China; Department of Urology, University of California, San Francisco, CA, United States
| | - Xin Liu
- Department of Pediatric Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China; Department of Urology, University of California, San Francisco, CA, United States
| | - Joel Shen
- Department of Urology, University of California, San Francisco, CA, United States
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, CA, United States
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, CA, United States
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, CA, United States.
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Wang S, Shi M, Zhu D, Mathews R, Zheng Z. External Genital Development, Urethra Formation, and Hypospadias Induction in Guinea Pig: A Double Zipper Model for Human Urethral Development. Urology 2017; 113:179-186. [PMID: 29155192 DOI: 10.1016/j.urology.2017.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To determine whether the guinea pig phallus would be an appropriate model of human penile development, we characterized the embryology and sexual differentiation of guinea pig external genitalia and attended to induce hypospadias in males and tubular urethra formation in females pharmacologically. MATERIALS AND METHODS The external genitalia of guinea pig were collected from genital swelling initiation to newborn stages, and scanning electronic microscopy and histology were performed to visualize the morphology and structure. Immunohistochemistry was used to determine the androgen receptor localization. Bicalutamide and methyltestosterone were given to pregnant dams to reveal the role and timing of androgen in guinea pig penile masculinization. RESULTS Canalization and dorsal-to-ventral movement of the urethral canal develops the urethral groove in both sexes, and then the males perform distal-opening-proximal-closing to form tubular urethra. More nuclear-localized androgen receptor is found in proximal genital tubercles of males than in females at (E) 29. Antiandrogen treatment at E26-E30 can cause hypospadias, and methyltestosterone administration at E27-E31 can induce tubular urethra formation in females. CONCLUSION Fetal development of the guinea pig phallus is homologous to that of humans. Although guinea pig has structures similar to mouse, the urethral groove and the tubular urethra formation are more similar to humans. Antiandrogen treatment causes hypospadias in males and additional androgen induces tubular urethra formation in females. Thus, guinea pig is an appropriate model for further study of cellular and molecular mechanisms involved in distal-opening-proximal-closing in tubular urethra formation and the evaluation of the pathophysiological processes of hypospadias.
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Affiliation(s)
- Shanshan Wang
- Department of Physiology, School of Medicine, Southern Illinois University Carbondale, Carbondale, IL
| | - Mingxin Shi
- Department of Physiology, School of Medicine, Southern Illinois University Carbondale, Carbondale, IL
| | - Dongqing Zhu
- Department of Physiology, School of Medicine, Southern Illinois University Carbondale, Carbondale, IL; Department of Pharmacy, Jiangsu Food & Pharmaceutical Science College, Huai'an, Jiangsu Province, China
| | - Ranjiv Mathews
- Department of Urology, School of Medicine, Southern Illinois University, Springfield, IL
| | - Zhengui Zheng
- Department of Physiology, School of Medicine, Southern Illinois University Carbondale, Carbondale, IL.
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Isaacson D, Shen J, Cao M, Sinclair A, Yue X, Cunha G, Baskin L. Renal Subcapsular xenografing of human fetal external genital tissue - A new model for investigating urethral development. Differentiation 2017; 98:1-13. [PMID: 29031189 DOI: 10.1016/j.diff.2017.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/26/2017] [Accepted: 09/11/2017] [Indexed: 12/01/2022]
Abstract
In this paper, we introduce our novel renal subcapsular xenograft model for the study of human penile urethral and clitoral development. We grafted fifteen intact fetal penes and clitorides 8-11 weeks fetal age under the renal capsules of gonadectomized athymic mice. The mice were treated with a subcutaneous pellet of dihydrotestosterone (DHT), diethylstilbestrol (DES) or untreated with hormones. Xenografts were harvested after fourteen days of growth and analyzed via serial histologic sectioning and immunostaining for Ki-67, cytokeratins 6, 7 and 10, uroplakin and the androgen receptor. Non-grafted specimens of similar fetal age were sectioned and immunostained for the same antigenic markers. 14/15 (93.3%) grafts were successfully propagated and harvested. The developing urethral plate, urethral groove, tubular urethra, corporal bodies and preputial lamina were easily identifiable. These structures demonstrated robust cellularity, appropriate architecture and abundant Ki-67 expression. Expression patterns of cytokeratins 6, 7 and 10, uroplakin and the androgen receptor in xenografted specimens demonstrated characteristic male/female differences analogous to non-grafted specimens. DHT treatment reliably produced tubularization of nascent urethral and vestibular structures and male patterns of androgen receptor expression in grafts of both genetic sexes while estrogenic or hormonally absent conditions reliably resulted in a persistent open urethral/vestibular groove and female patterns of androgen receptor expression. This model's success enables further study into causal pathways by which endocrine-disrupting and endocrine-mimicking substances may directly cause disruption of normal human urethral development or hypospadias.
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Affiliation(s)
- Dylan Isaacson
- School of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Joel Shen
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Xuan Yue
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Gerald Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA, USA; Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA, USA.
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Flutamide-induced hypospadias in rats: A critical assessment. Differentiation 2017; 94:37-57. [DOI: 10.1016/j.diff.2016.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/23/2016] [Accepted: 12/02/2016] [Indexed: 01/03/2023]
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