1
|
Wiener SV. Effects of the environment on the evolution of the vertebrate urinary tract. Nat Rev Urol 2023; 20:719-738. [PMID: 37443264 DOI: 10.1038/s41585-023-00794-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2023] [Indexed: 07/15/2023]
Abstract
Evolution of the vertebrate urinary system occurs in response to numerous selective pressures, which have been incompletely characterized. Developing research into urinary evolution led to the occurrence of clinical applications and insights in paediatric urology, reproductive medicine, urolithiasis and other domains. Each nephron segment and urinary organ has functions that can be contextualized within an evolutionary framework. For example, the structure and function of the glomerulus and proximal tubule are highly conserved, enabling blood cells and proteins to be retained, and facilitating the elimination of oceanic Ca+ and Mg+. Urea emerged as an osmotic mediator during evolution, as cells of large organisms required increased precision in the internal regulation of salinity and solutes. As the first vertebrates moved from water to land, acid-base regulation was shifted from gills to skin and kidneys in amphibians. In reptiles and birds, solute regulation no longer occurred through the skin but through nasal salt glands and post-renally, within the cloaca and the rectum. In placental mammals, nasal salt glands are absent and the rectum and urinary tracts became separate, which limited post-renal urine concentration and led to the necessity of a kidney capable of high urine concentration. Considering the evolutionary and environmental selective pressures that have contributed to renal evolution can help to gain an increased understanding of renal physiology.
Collapse
Affiliation(s)
- Scott V Wiener
- Department of Urology, SUNY Upstate Medical University, Syracuse, NY, USA.
| |
Collapse
|
2
|
Amato CM, Yao HHC, Zhao F. One Tool for Many Jobs: Divergent and Conserved Actions of Androgen Signaling in Male Internal Reproductive Tract and External Genitalia. Front Endocrinol (Lausanne) 2022; 13:910964. [PMID: 35846302 PMCID: PMC9280649 DOI: 10.3389/fendo.2022.910964] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/25/2022] [Indexed: 11/13/2022] Open
Abstract
In the 1940s, Alfred Jost demonstrated the necessity of testicular secretions, particularly androgens, for male internal and external genitalia differentiation. Since then, our knowledge of androgen impacts on differentiation of the male internal (Wolffian duct) and external genitalia (penis) has been drastically expanded upon. Between these two morphologically and functionally distinct organs, divergent signals facilitate the establishment of tissue-specific identities. Conversely, conserved actions of androgen signaling are present in both tissues and are largely responsible for the growth and expansion of the organs. In this review we synthesize the existing knowledge of the cell type-specific, organ specific, and conserved signaling mechanisms of androgens. Mechanistic studies on androgen signaling in the Wolffian duct and male external genitalia have largely been conducted in mouse model organisms. Therefore, the majority of the review is focused on mouse model studies.
Collapse
Affiliation(s)
- Ciro M. Amato
- Reproductive Developmental Biology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Humphrey H-C. Yao
- Reproductive Developmental Biology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Fei Zhao
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
3
|
Mark M, Teletin M, Wendling O, Vonesch JL, Féret B, Hérault Y, Ghyselinck NB. Pathogenesis of Anorectal Malformations in Retinoic Acid Receptor Knockout Mice Studied by HREM. Biomedicines 2021; 9:742. [PMID: 34203310 PMCID: PMC8301324 DOI: 10.3390/biomedicines9070742] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/12/2022] Open
Abstract
Anorectal malformations (ARMs) are relatively common congenital abnormalities, but their pathogenesis is poorly understood. Previous gene knockout studies indicated that the signalling pathway mediated by the retinoic acid receptors (RAR) is instrumental to the formation of the anorectal canal and of various urogenital structures. Here, we show that simultaneous ablation of the three RARs in the mouse embryo results in a spectrum of malformations of the pelvic organs in which anorectal and urinary bladder ageneses are consistently associated. We found that these ageneses could be accounted for by defects in the processes of growth and migration of the cloaca, the embryonic structure from which the anorectal canal and urinary bladder originate. We further show that these defects are preceded by a failure of the lateral shift of the umbilical arteries and propose vascular abnormalities as a possible cause of ARM. Through the comparisons of these phenotypes with those of other mutant mice and of human patients, we would like to suggest that morphological data may provide a solid base to test molecular as well as clinical hypotheses.
Collapse
Affiliation(s)
- Manuel Mark
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
- Service de Biologie de la Reproduction, Hôpitaux Universitaires de Strasbourg (HUS), 67300 Schiltigheim, France
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Marius Teletin
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
- Service de Biologie de la Reproduction, Hôpitaux Universitaires de Strasbourg (HUS), 67300 Schiltigheim, France
| | - Olivia Wendling
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Jean-Luc Vonesch
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
| | - Betty Féret
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
| | - Yann Hérault
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France
| | - Norbert B. Ghyselinck
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (M.T.); (O.W.); (J.-L.V.); (B.F.); (Y.H.); (N.B.G.)
| |
Collapse
|
4
|
New Insights on the Basic Science of Bladder Exstrophy-epispadias Complex. Urology 2020; 147:256-263. [PMID: 33049233 DOI: 10.1016/j.urology.2020.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 11/20/2022]
Abstract
The exstrophy-epispadias complex is a rare congenital anomaly presenting as a wide spectrum of disorders. The complex nature of this malformation leads to continuous investigations of the basic science concepts behind it. Elucidating these concepts allows one to fully understand the mechanisms behind the disease in order to improve diagnosis, management, and treatment ultimately leading to improvement in patient quality of life. Multiple technological advancements within the last 10 years have been made allowing for new studies to be conducted. Herein, the authors conduct a literature review of studies from 2009 to 2019, considering novel theories regarding the genetics, embryology, bladder, bony pelvis, prostate, and genitalia of patients with bladder exstrophy-epispadias complex.
Collapse
|
5
|
Liaw A, Cunha GR, Shen J, Cao M, Liu G, Sinclair A, Baskin L. Development of the human bladder and ureterovesical junction. Differentiation 2018; 103:66-73. [PMID: 30236462 DOI: 10.1016/j.diff.2018.08.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 11/13/2022]
Abstract
The urinary bladder collects urine from the kidneys and stores it until the appropriate moment for voiding. The trigone and ureterovesical junctions are key to bladder function, by allowing one-way passage of urine into the bladder without obstruction. Embryological development of these structures has been studied in multiple animal models as well as humans. In this report we review the existing literature on bladder development and cellular signalling with particular focus on bladder development in humans. The bladder and ureterovesical junction form primarily during the fourth to eighth weeks of gestation, and arise from the primitive urogenital sinus following subdivision of the cloaca. The bladder develops through mesenchymal-epithelial interactions between the endoderm of the urogenital sinus and mesodermal mesenchyme. Key signalling factors in bladder development include shh, TGF-β, Bmp4, and Fgfr2. A concentration gradient of shh is particularly important in development of bladder musculature, which is vital to bladder function. The ureterovesical junction forms from the interaction between the Wolffian duct and the bladder. The ureteric bud arises from the Wolffian duct and is incorporated into the developing bladder at the trigone. It was previously thought that the trigonal musculature developed primarily from the Wolffian duct, but it has been shown to develop primarily from bladder mesenchyme. Following emergence of the ureters from the Wolffian ducts, extensive epithelial remodelling brings the ureters to their final trigonal positions via vitamin A-induced apoptosis. Perturbation of this process is implicated in clinical obstruction or urine reflux. Congenital malformations include ureteric duplication and bladder exstrophy.
Collapse
Affiliation(s)
- Aron Liaw
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Joel Shen
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Mei Cao
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Ge Liu
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Adriane Sinclair
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States
| | - Laurence Baskin
- Department of Urology, University of California, San Francisco, San Francisco, CA Division of Pediatric Urology, University of California San Francisco Benioff Children's Hospital, San Francisco, CA 94143, United States.
| |
Collapse
|
6
|
Zhou Z, Wang J, Guo C, Chang W, Zhuang J, Zhu P, Li X. Temporally Distinct Six2-Positive Second Heart Field Progenitors Regulate Mammalian Heart Development and Disease. Cell Rep 2017; 18:1019-1032. [PMID: 28122228 DOI: 10.1016/j.celrep.2017.01.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/20/2016] [Accepted: 12/30/2016] [Indexed: 12/15/2022] Open
Abstract
The embryonic process of forming a complex structure such as the heart remains poorly understood. Here, we show that Six2 marks a dynamic subset of second heart field progenitors. Six2-positive (Six2+) progenitors are rapidly recruited and assigned, and their descendants are allocated successively to regions of the heart from the right ventricle (RV) to the pulmonary trunk. Global ablation of Six2+ progenitors resulted in RV hypoplasia and pulmonary atresia. An early stage-specific ablation of a small subset of Six2+ progenitors did not cause any apparent structural defect at birth but rather resulted in adult-onset cardiac hypertrophy and dysfunction. Furthermore, Six2 expression depends in part on Shh signaling, and Shh deletion resulted in severe deficiency of Six2+ progenitors. Collectively, these findings unveil the chronological features of cardiogenesis, in which the mammalian heart is built sequentially by temporally distinct populations of cardiac progenitors, and provide insights into late-onset congenital heart disease.
Collapse
Affiliation(s)
- Zhengfang Zhou
- Departments of Urology and Surgery, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA; Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510100, China
| | - Jingying Wang
- Departments of Urology and Surgery, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Chaoshe Guo
- Departments of Urology and Surgery, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Weiting Chang
- Divisions of Genetics and Cardiovascular Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jian Zhuang
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510100, China
| | - Ping Zhu
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510100, China.
| | - Xue Li
- Departments of Urology and Surgery, Boston Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| |
Collapse
|
7
|
Clarification of mammalian cloacal morphogenesis using high-resolution episcopic microscopy. Dev Biol 2015; 409:106-113. [PMID: 26485363 DOI: 10.1016/j.ydbio.2015.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 10/07/2015] [Accepted: 10/15/2015] [Indexed: 01/03/2023]
Abstract
The developmental process through which the cloaca transforms from one hollow structure to two separated urinary and digestive outlets remains controversial and speculative. Here, we use high-resolution episcopic microscopy to examine a comprehensive series of normal and mutant mouse cloaca in which the detailed 3-dimensional (3-D) morphological features are illuminated throughout the development. We provide evidence that the dorsal peri-cloacal mesenchyme (dPCM) remains stationary while other surrounding tissues grow towards it. This causes dramatic changes of spatial relationship among caudal structures and morphological transformation of the cloaca. The 3-D characterizations of Dkk1 mutants reveal a hyperplastic defect of dPCM, which leads to a significant anterior shift of the caudal boundary of the cloaca, premature occlusion of the cloaca and, imperforate anus phenotype. Conversely, Shh knockout causes a severe hypoplastic defect of cloaca mesenchyme including dPCM and persistent cloaca. Collectively, these findings suggest that formation of the dPCM is critical for cloacal morphogenesis and furthermore, growth and movement of the mesenchymal tissues towards the dPCM lead to the cloaca occlusion and separation of the urinary and digestive outlets.
Collapse
|
8
|
Systematic stereoscopic analyses for cloacal development: The origin of anorectal malformations. Sci Rep 2015; 5:13943. [PMID: 26354024 PMCID: PMC4564729 DOI: 10.1038/srep13943] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 08/05/2015] [Indexed: 12/28/2022] Open
Abstract
The division of the embryonic cloaca is the most essential event for the formation of digestive and urinary tracts. The defective development of the cloaca results in anorectal malformations (ARMs; 2–5 per 10,000 live births). However, the developmental and pathogenic mechanisms of ARMs are unclear. In the current study, we visualized the epithelia in the developing cloaca and nephric ducts (NDs). Systemic stereoscopic analyses revealed that the ND-cloaca connection sites shifted from the lateral-middle to dorsal-anterior part of the cloaca during cloacal division from E10.5 to E11.5 in mouse embryos. Genetic cell labeling analyses revealed that the cells in the ventral cloacal epithelium in the early stages rarely contributed to the dorsal part. Moreover, we revealed the possible morphogenetic movement of endodermal cells within the anterior part of the urogenital sinus and hindgut. These results provide the basis for understanding both cloacal development and the ARM pathogenesis.
Collapse
|
9
|
Harada M, Omori A, Nakahara C, Nakagata N, Akita K, Yamada G. Tissue-specific roles of FGF signaling in external genitalia development. Dev Dyn 2015; 244:759-73. [DOI: 10.1002/dvdy.24277] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 03/22/2015] [Accepted: 03/22/2015] [Indexed: 11/11/2022] Open
Affiliation(s)
- Masayo Harada
- Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto Japan
- Department of Clinical Anatomy; Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
| | - Akiko Omori
- Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto Japan
- Department of Developmental Genetics; Institute of Advanced Medicine; Wakayama Medical University; Wakayama Japan
| | - Chiaki Nakahara
- Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto Japan
| | - Naomi Nakagata
- Division of Reproductive Engineering; Center for Animal Resources and Development, Kumamoto University; Kumamoto Japan
| | - Keiichi Akita
- Department of Clinical Anatomy; Graduate School of Medical and Dental Sciences; Tokyo Medical and Dental University; Tokyo Japan
| | - Gen Yamada
- Institute of Molecular Embryology and Genetics; Kumamoto University; Kumamoto Japan
- Department of Developmental Genetics; Institute of Advanced Medicine; Wakayama Medical University; Wakayama Japan
| |
Collapse
|
10
|
The Great Divide: Understanding Cloacal Septation, Malformation, and Implications for Surgeons. Pediatr Surg Int 2014; 30:1089-95. [PMID: 25217828 PMCID: PMC4302733 DOI: 10.1007/s00383-014-3593-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/04/2014] [Indexed: 12/28/2022]
Abstract
The anorectal and urogenital systems arise from a common embryonic structure termed cloaca. Subsequent development leads to the division/septation of the cloaca into the urethra, urinary bladder, vagina, anal canal, and rectum. Defective cloacal development and the resulting anorectal and urogenital malformations are some of the most severe congenital anomalies encountered in children. In the most severe form in females, the rectum, vagina, and urethra fail to develop separately and drain via a single common channel known as a cloaca into the perineum. In this review, we summarize our current knowledge of embryonic cloaca development and malformation, and compare them to what has already been described in the literature. We describe the use of mouse models of cloaca malformation to understand which signaling pathways and cellular mechanisms are involved in the process of normal cloaca development. We also discuss the embryological correlation of the epithelial and stromal histology found in step sections of the common channel in 14 human cloaca malformations. Finally, we highlight the significance of these findings, compare them to prior studies, and discuss their implications for the pediatric surgeons. Understanding and identifying the molecular basis for cloaca malformation could provide foundation for tissue engineering efforts that in the future would reflect better surgical reconstruction and improved quality of life for patients.
Collapse
|
11
|
Pierre K, Borer J, Phelps A, Chow JS. Bladder exstrophy: current management and postoperative imaging. Pediatr Radiol 2014; 44:768-86; quiz 765-7. [PMID: 24939762 DOI: 10.1007/s00247-014-2892-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 12/01/2013] [Accepted: 01/20/2014] [Indexed: 11/30/2022]
Abstract
Bladder exstrophy is a rare malformation characterized by an infra-umbilical abdominal wall defect, incomplete closure of the bladder with mucosa continuous with the abdominal wall, epispadias, and alterations in the pelvic bones and muscles. It is part of the exstrophy-epispadias complex, with cloacal exstrophy on the severe and epispadias on the mild ends of the spectrum. Bladder exstrophy is the most common of these entities and is more common in boys. The goal of this paper is to describe common methods of repair and to provide an imaging review of the postoperative appearances.
Collapse
Affiliation(s)
- Ketsia Pierre
- Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA, 02115, USA,
| | | | | | | |
Collapse
|
12
|
Guo C, Sun Y, Guo C, MacDonald BT, Borer JG, Li X. Dkk1 in the peri-cloaca mesenchyme regulates formation of anorectal and genitourinary tracts. Dev Biol 2014; 385:41-51. [PMID: 24479159 DOI: 10.1016/j.ydbio.2013.10.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Anorectal malformation (ARM) is a common birth defect but the developmental history and the underlying molecular mechanism are poorly understood. Using murine genetic models, we report here that a signaling molecule Dickkopf-1 (Dkk1) is a critical regulator. The anorectal and genitourinary tracts are major derivatives of caudal hindgut, or the cloaca.Dkk1 is highly expressed in the dorsal peri-cloacal mesenchymal (dPCM) progenitors. We show that the deletion of Dkk1 causes the imperforate anus with rectourinary fistula. Mutant genital tubercles exhibit a preputial hypospadias phenotype and premature urethral canalization.Dkk1 mutants have an ectopic expansion of the dPCM tissue, which correlates with an aberrant increase of cell proliferation and survival. This ectopic tissue is detectable before the earliest sign of the anus formation, suggesting that it is most likely the primary or early cause of the defect. Deletion of Dkk1 results in an elevation of the Wnt/ß-catenin activity. Signaling molecules Shh, Fgf8 and Bmp4 are also upregulated. Furthermore, genetic hyperactivation of Wnt/ß-catenin signal pathway in the cloacal mesenchyme partially recapitulates Dkk1 mutant phenotypes. Together, these findings underscore the importance ofDKK1 in regulating behavior of dPCM progenitors, and suggest that formation of anus and urethral depends on Dkk1-mediated dynamic inhibition of the canonical Wnt/ß-catenin signal pathway.
Collapse
Affiliation(s)
- Chaoshe Guo
- Department of Urology, Department of Surgery and Pathology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Ye Sun
- Department of Urology, Department of Surgery and Pathology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Chunming Guo
- Department of Urology, Department of Surgery and Pathology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Bryan T MacDonald
- The F. M. Kirby Neurobiology Center, Department of Neurology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Joseph G Borer
- Department of Urology, Department of Surgery and Pathology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Xue Li
- Department of Urology, Department of Surgery and Pathology; Boston Children's Hospital, 300 Longwood Avenue; Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
13
|
Ipulan LA, Suzuki K, Matsushita S, Suzuki H, Okazawa M, Jacinto S, Hirai SI, Yamada G. Development of the external genitalia and their sexual dimorphic regulation in mice. Sex Dev 2014; 8:297-310. [PMID: 24503953 DOI: 10.1159/000357932] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The study of the external genitalia is divided into 2 developmental stages: the formation and growth of a bipotential genital tubercle (GT) and the sexual differentiation of the male and female GT. The sexually dimorphic processes, which occur during the second part of GT differentiation, are suggested to be governed by androgen signaling and more recently crosstalk with other signaling factors. The process of elucidating the regulatory mechanisms of hormone signaling towards other signaling networks in the GT is still in its early stages. Nevertheless, it is becoming a productive area of research. This review summarizes various studies on the development of the murine GT and the defining characteristics of a masculinized GT and presents the different signaling pathways possibly involved during masculinization.
Collapse
Affiliation(s)
- Lerrie Ann Ipulan
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | | | | | | | | | | | | | | |
Collapse
|