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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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Elmore SA, Kavari SL, Hoenerhoff MJ, Mahler B, Scott BE, Yabe K, Seely JC. Histology Atlas of the Developing Mouse Urinary System With Emphasis on Prenatal Days E10.5-E18.5. Toxicol Pathol 2019; 47:865-886. [PMID: 31599209 DOI: 10.1177/0192623319873871] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Congenital abnormalities of the urinary tract are some of the most common human developmental abnormalities. Several genetically engineered mouse models have been developed to mimic these abnormalities and aim to better understand the molecular mechanisms of disease. This atlas has been developed as an aid to pathologists and other biomedical scientists for identification of abnormalities in the developing murine urinary tract by cataloguing normal structures at each stage of development. Hematoxylin and eosin- and immunohistochemical-stained sections are provided, with a focus on E10.5-E18.5, as well as a brief discussion of postnatal events in urinary tract development. A section on abnormalities in the development of the urinary tract is also provided, and molecular mechanisms are presented as supplementary material. Additionally, overviews of the 2 key processes of kidney development, branching morphogenesis and nephrogenesis, are provided to aid in the understanding of the complex organogenesis of the kidney. One of the key findings of this atlas is the histological identification of the ureteric bud at E10.5, as previous literature has provided conflicting reports on the initial point of budding. Furthermore, attention is paid to points where murine development is significantly distinct from human development, namely, in the cessation of nephrogenesis.
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Affiliation(s)
- Susan A Elmore
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, Durham, NC, USA
| | - Sanam L Kavari
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, Durham, NC, USA
| | - Mark J Hoenerhoff
- In Vivo Animal Core, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Beth Mahler
- Experimental Pathology Laboratories, Inc, Research Triangle Park, NC, USA
| | | | - Koichi Yabe
- Pharmacovigilance Department, Daiichi Sankyo Co, Ltd, Tokyo, Japan
| | - John C Seely
- Experimental Pathology Laboratories, Inc, Research Triangle Park, NC, USA
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Stewart MK, Mattiske DM, Pask AJ. In utero exposure to both high- and low-dose diethylstilbestrol disrupts mouse genital tubercle development†. Biol Reprod 2018; 99:1184-1193. [DOI: 10.1093/biolre/ioy142] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 06/19/2018] [Indexed: 02/04/2023] Open
Affiliation(s)
- Melanie K Stewart
- School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Deidre M Mattiske
- School of BioSciences, The University of Melbourne, Victoria, Australia
| | - Andrew J Pask
- School of BioSciences, The University of Melbourne, Victoria, Australia
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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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Sinclair AW, Glickman SE, Baskin L, Cunha GR. Anatomy of mole external genitalia: Setting the record straight. Anat Rec (Hoboken) 2016; 299:385-99. [PMID: 26694958 DOI: 10.1002/ar.23309] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/02/2015] [Accepted: 11/08/2015] [Indexed: 12/19/2022]
Abstract
Anatomy of male and female external genitalia of adult mice (Mus musculus) and broad-footed moles (Scapanus latimanus) was re-examined to provide more meaningful anatomical terminology. In the past the perineal appendage of male broad-footed moles has been called the penis, while the female perineal appendage has been given several terms (e.g. clitoris, penile clitoris, peniform clitoris and others). Histological examination demonstrates that perineal appendages of male and female broad-footed moles are the prepuce, which in both sexes are covered externally with a hair-bearing epidermis and lacks erectile bodies. The inner preputial epithelium is non-hair-bearing and defines the preputial space in both sexes. The penis of broad-footed moles lies deep within the preputial space, is an "internal organ" in the resting state and contains the penile urethra, os penis, and erectile bodies. The clitoris of broad-footed moles is defined by a U-shaped clitoral epithelial lamina. Residing within clitoral stroma encompassed by the clitoral epithelial lamina is the corpus cavernosum, blood-filled spaces and the urethra. External genitalia of male and female mice are anatomically similar to that of broad-footed moles with the exception that in female mice the clitoris contains a small os clitoridis and lacks defined erectile bodies, while male mice have an os penis and a prominent distal cartilaginous structure within the male urogenital mating protuberance (MUMP). Clitori of female broad-footed moles lack an os clitoridis but contain defined erectile bodies, while male moles have an os penis similar to the mouse but lack the distal cartilaginous structure.
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Affiliation(s)
- Adriane Watkins Sinclair
- Department of Urology, University of California San Francisco, 400 Parnassus Avenue, Box A610, San Francisco, California, 94143
| | - Stephen E Glickman
- Departments of Psychology and Integrative Biology, University of California, Berkeley, California, 94720
| | - Laurence Baskin
- Department of Urology, University of California San Francisco, 400 Parnassus Avenue, Box A610, San Francisco, California, 94143
| | - Gerald R Cunha
- Department of Urology, University of California San Francisco, 400 Parnassus Avenue, Box A610, San Francisco, California, 94143
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Georgas KM, Armstrong J, Keast JR, Larkins CE, McHugh KM, Southard-Smith EM, Cohn MJ, Batourina E, Dan H, Schneider K, Buehler DP, Wiese CB, Brennan J, Davies JA, Harding SD, Baldock RA, Little MH, Vezina CM, Mendelsohn C. An illustrated anatomical ontology of the developing mouse lower urogenital tract. Development 2015; 142:1893-908. [PMID: 25968320 DOI: 10.1242/dev.117903] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 04/01/2015] [Indexed: 01/10/2023]
Abstract
Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation.
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Affiliation(s)
- Kylie M Georgas
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Jane Armstrong
- Center for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Janet R Keast
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Christine E Larkins
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Kirk M McHugh
- Centre for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital and Division of Anatomy, The Ohio State University, Columbus, OH 43205/10, USA
| | - E Michelle Southard-Smith
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Martin J Cohn
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA Department of Biology, Genetics Institute, University of Florida, Gainesville, FL 32610, USA Howard Hughes Medical Institute, University of Florida, Gainesville, FL 32610, USA
| | | | - Hanbin Dan
- Columbia University, Department of Urology, New York, NY 10032, USA
| | - Kerry Schneider
- Columbia University, Department of Urology, New York, NY 10032, USA
| | - Dennis P Buehler
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Carrie B Wiese
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jane Brennan
- Center for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Jamie A Davies
- Center for Integrative Physiology, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Simon D Harding
- MRC Human Genetics Unit, MRC IGMM, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Richard A Baldock
- MRC Human Genetics Unit, MRC IGMM, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Melissa H Little
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, Queensland 4072, Australia
| | - Chad M Vezina
- University of Wisconsin-Madison, School of Veterinary Medicine, Madison, WI 53706, USA
| | - Cathy Mendelsohn
- Columbia University, Department of Urology, New York, NY 10032, USA
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Sexually dimorphic expression of Mafb regulates masculinization of the embryonic urethral formation. Proc Natl Acad Sci U S A 2014; 111:16407-12. [PMID: 25362053 DOI: 10.1073/pnas.1413273111] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Masculinization of external genitalia is an essential process in the formation of the male reproductive system. Prominent characteristics of this masculinization are the organ size and the sexual differentiation of the urethra. Although androgen is a pivotal inducer of the masculinization, the regulatory mechanism under the control of androgen is still unknown. Here, we address this longstanding question about how androgen induces masculinization of the embryonic external genitalia through the identification of the v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B (Mafb) gene. Mafb is expressed prominently in the mesenchyme of male genital tubercle (GT), the anlage of external genitalia. MAFB expression is rarely detected in the mesenchyme of female GTs. However, exposure to exogenous androgen induces its mesenchymal expression in female GTs. Furthermore, MAFB expression is prominently down-regulated in male GTs of androgen receptor (Ar) KO mice, indicating that AR signaling is necessary for its expression. It is revealed that Mafb KO male GTs exhibit defective embryonic urethral formation, giving insight into the common human congenital anomaly hypospadias. However, the size of Mafb KO male GTs is similar with that of wild-type males. Moreover, androgen treatment fails to induce urethral masculinization of the GTs in Mafb KO mice. The current results provide evidence that Mafb is an androgen-inducible, sexually dimorphic regulator of embryonic urethral masculinization.
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Carmichael SL, Shaw GM, Lammer EJ. Environmental and genetic contributors to hypospadias: a review of the epidemiologic evidence. BIRTH DEFECTS RESEARCH. PART A, CLINICAL AND MOLECULAR TERATOLOGY 2012; 94:499-510. [PMID: 22678668 PMCID: PMC3393839 DOI: 10.1002/bdra.23021] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 03/22/2012] [Accepted: 03/28/2012] [Indexed: 12/28/2022]
Abstract
This review evaluates current knowledge related to trends in the prevalence of hypospadias, the association of hypospadias with endocrine-disrupting exposures, and the potential contribution of genetic susceptibility to its etiology. The review focuses on epidemiologic evidence. Increasing prevalence of hypospadias has been observed, but such increases tend to be localized to specific regions or time periods. Thus, generalized statements that hypospadias is increasing are unsupported. Owing to the limitations of study designs and inconsistent results, firm conclusions cannot be made regarding the association of endocrine-disrupting exposures with hypospadias. Studies with more rigorous study designs (e.g., larger and more detailed phenotypes) and exposure assessment that encompasses more breadth and depth (e.g., specific endocrine-related chemicals) will be critical to make better inferences about these important environmental exposures. Many candidate genes for hypospadias have been identified, but few of them have been examined to an extent that enables solid conclusions. Further study is needed that includes larger sample sizes, comparison groups that are more representative of the populations from which the cases were derived, phenotype-specific analyses, and more extensive exploration of variants. In conclusion, examining the associations of environmental and genetic factors with hypospadias remain important areas of inquiry, although our actual understanding of their contribution to hypospadias risk in humans is currently limited.
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Affiliation(s)
- Suzan L Carmichael
- Department of Pediatrics, Division of Neonatology, Stanford University School of Medicine, California, USA.
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Chen H, Yong W, Hinds TD, Yang Z, Zhou Y, Sanchez ER, Shou W. Fkbp52 regulates androgen receptor transactivation activity and male urethra morphogenesis. J Biol Chem 2010; 285:27776-84. [PMID: 20605780 PMCID: PMC2934645 DOI: 10.1074/jbc.m110.156091] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 07/01/2010] [Indexed: 01/12/2023] Open
Abstract
Hypospadias is a common birth defect in humans, yet its etiology and pattern of onset are largely unknown. Recent studies have shown that male mice with targeted ablation of FK506-binding protein-52 (Fkbp52) develop hypospadias, most likely due to actions of Fkbp52 as a molecular co-chaperone of the androgen receptor (AR). Here, we further dissect the developmental and molecular mechanisms that underlie hypospadias in Fkbp52-deficient mice. Scanning electron microscopy revealed a defect in the elevation of prepucial swelling that led to the onset of the ventral penile cleft. Interestingly, expression of Fkbp52 was highest in the ventral aspect of the developing penis that undergoes fusion of the urethral epithelium. Although in situ hybridization and immunohistochemical analyses suggested that Fkbp52 mutants had a normal urethral epithelium signaling center and epithelial differentiation, a reduced apoptotic cell index at ventral epithelial cells at the site of fusion and a defect of genital mesenchymal cell migration were observed. Supplementation of gestating females with excess testosterone partially rescued the hypospadic phenotype in Fkbp52 mutant males, showing that loss of Fkbp52 desensitizes AR to hormonal activation. Direct measurement of AR activity was performed in mouse embryonic fibroblast cells treated with dihydrotestosterone or synthetic agonist R1881. Reduced AR activity at genes controlling sexual dimorphism and cell growth was found in Fkbp52-deficient mouse embryonic fibroblast cells. However, chromatin immunoprecipitation analysis revealed normal occupancy of AR at gene promoters, suggesting that Fkbp52 exerts downstream effects on the transactivation function of AR. Taken together, our data show Fkbp52 to be an important molecular regulator in the androgen-mediated pathway of urethra morphogenesis.
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Affiliation(s)
- Hanying Chen
- From the Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Weidong Yong
- From the Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Terry D. Hinds
- the Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, College of Medicine, University of Toledo, Toledo, Ohio 43614
| | - Zuocheng Yang
- From the Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
- the Department of Pediatrics, Third Xiang-Ya Hospital, Central South University, Xiang-Ya School of Medicine, Changsha 410013, China, and
| | - Yuhong Zhou
- From the Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
- the Department of Pharmacology, Harbin Medical University, Harbin 150086, China
| | - Edwin R. Sanchez
- the Center for Diabetes and Endocrine Research, Department of Physiology and Pharmacology, College of Medicine, University of Toledo, Toledo, Ohio 43614
| | - Weinian Shou
- From the Riley Heart Research Center, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
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Liu B, Agras K, Willingham E, Vilela MLB, Baskin LS. Activating transcription factor 3 is estrogen-responsive in utero and upregulated during sexual differentiation. HORMONE RESEARCH 2006; 65:217-22. [PMID: 16569931 DOI: 10.1159/000092402] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Accepted: 01/30/2006] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Synthetic estrogens induce hypospadias, an anomaly of genital tubercle/urethral development. Activating transcription factor 3 (ATF3), which is estrogen-responsive in vitro, is upregulated in hypospadiac human tissue. We used a mouse model of steroid-dependent genital tubercle development to elucidate the ontogeny of ATF3 expression and the developmental response of ATF3 in vivo to estrogen exposure. METHODS We used quantitative RT-PCR to assess ontogenic expression of ATF3 and its response to estrogen treatment in utero. Immunohistochemistry was used to localize the protein. RESULTS Quantitative RT-PCR showed that ATF3 mRNA is upregulated in all estrogen-exposed fetal genital tubercles compared to controls (p = 0.024), including specifically in males exposed in utero (p = 0.049). Additionally, its expression increases significantly during the period of sexual differentiation in both sexes and significantly correlates with female development (p = 0.004), a phenomenon that appears to be attributable to higher levels at birth in females. The protein localizes in the nucleus, as expected. CONCLUSIONS ATF3 is estrogen-responsive in vivo. The response of ATF3 to estrogenic stimulation in utero at an earlier stage may contribute to urethral abnormalities observed in estrogen-exposed male fetuses, although it is likely not the only gene involved, which supports the general understanding that hypospadias is subject to multifactorial influences. ATF3 may therefore be an appropriate gene for further investigations in an endocrine context.
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Affiliation(s)
- Benchun Liu
- Center for the Study and Treatment of Hypospadias, Department of Urology, University of California, San Francisco, Calif. 94143, USA
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Liu B, Wang Z, Lin G, Agras K, Ebbers M, Willingham E, Baskin LS. Activating transcription factor 3 is up-regulated in patients with hypospadias. Pediatr Res 2005; 58:1280-3. [PMID: 16306208 DOI: 10.1203/01.pdr.0000187796.28007.2d] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hypospadias is a congenital anomaly of the genitalia characterized by abnormalities of the urethra and foreskin, with the urethral meatus located in an abnormal position anywhere from the distal ventral penile shaft to the perineum. Because the incidence of hypospadias is approximately 1/200-1/300 live male births, it is one of the most common congenital malformations, but its etiology is largely uncharacterized. Genomic analysis of hypospadic tissue indicated a potential role for activating transcription factor 3 (ATF3) in the development of this anomaly. ATF3 may be involved in homeostasis, wound healing, cell adhesion, or apoptosis, and normally it is expressed at a steady-state in quiescent cells. Additionally, it has been shown to be an estrogen-responsive gene, and the etiology of hypospadias may be related to in utero exposure to estrogenic or anti-androgenic compounds. We examined the expression of ATF3 in tissues from 28 children with hypospadias compared with 20 normal penile skin tissue samples from elective circumcision. Eighty-six percent of the hypospadias samples were immunohistochemically positive, compared with 13% of normal tissue samples. Seventy-five percent of hypospadias samples were positive from in situ hybridization, compared with 1% of circumcision samples. Our results indicate that ATF3 is up-regulated in the penile skin tissues of boys with hypospadias, suggesting a role for this transcription factor in the development of this abnormality. Because the etiology of hypospadias may include exposure to estrogenic compounds, the responsiveness of ATF3 to estrogen is also discussed.
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Affiliation(s)
- Benchun Liu
- Center for the Study and Treatment of Hypospadias, Department of Urology, University of California, San Francisco 94143, USA
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