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Di Giorgio NP, Bizzozzero-Hiriart M, Surkin PN, Repetto E, Bonaventura MM, Tabares FN, Bourguignon NS, Converti A, Gomez JMR, Bettler B, Lux-Lantos V. Deletion of GABAB receptors from Kiss1 cells affects glucose homeostasis without altering reproduction in male mice. Am J Physiol Endocrinol Metab 2023; 324:E314-E329. [PMID: 36652400 DOI: 10.1152/ajpendo.00129.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Kisspeptin and γ-amino butyric acid (GABA), synthesized in the central nervous system, are critical for reproduction. Both are also expressed in peripheral organs/tissues critical to metabolic control (liver/pancreas/adipose). Many kisspeptin neurons coexpress GABAB receptors (GABABR) and GABA controls kisspeptin expression and secretion. We developed a unique mouse lacking GABABR exclusively from kisspeptin cells/neurons (Kiss1-GABAB1KO) to evaluate the impact on metabolism/reproduction. We confirmed selective deletion of GABABR from Kiss1 cells in the anteroventral periventricular nucleus/periventricular nucleus continuum (AVPV/PeN; immunofluorescence and PCR) and arcuate nucleus (ARC), medial amygdala (MeA), pituitary, liver, and testes (PCR). Young Kiss1-GABAB1KO males were fertile, with normal LH and testosterone. Kiss1 expression was similar between genotypes in AVPV/PeN, ARC, MeA, bed nucleus of the stria terminalis (BNST), and peripheral organs (testis, liver, pituitary). Kiss1-GABAB1KO males presented higher fasted glycemia and insulin levels, an impaired response to a glucose overload, reduced insulin sensitivity, and marked insulin resistance. Interestingly, when Kiss1-GABAB1KO males got older (9 mo old) their body weight (BW) increased, in part due to an increase in white adipose tissue (WAT). Old Kiss1-GABAB1KO males showed higher fasted insulin, increased pancreatic insulin content, insulin resistance, and significantly decreased pancreatic kisspeptin levels. In sum, lack of GABABR specifically in Kiss1 cells severely impacts glucose homeostasis in male mice, reinforcing kisspeptin involvement in metabolic regulation. These alterations in glucose homeostasis worsened with aging. We highlight the impact of GABA through GABABR in the regulation of the pancreas kisspeptin system in contrast to liver kisspeptin that was not affected.NEW & NOTEWORTHY We developed a unique mouse lacking GABAB receptors specifically in Kiss1 cells to evaluate the impact on reproduction and metabolism. Knockout males showed a severe impact on glucose homeostasis, which worsened with aging. These results reinforce the proposed kisspeptin involvement in metabolic regulation and highlight the impact of GABA through GABABR in the regulation of the peripheral pancreas kisspeptin system.
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Affiliation(s)
- Noelia P Di Giorgio
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Marianne Bizzozzero-Hiriart
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Pablo N Surkin
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Esteban Repetto
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - María M Bonaventura
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Florencia N Tabares
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Nadia S Bourguignon
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Ayelén Converti
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Juan M Riaño Gomez
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
| | - Bernhard Bettler
- Department of Biomedicine, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Victoria Lux-Lantos
- Laboratorio de Neuroendocrinología, Instituto de Biología y Medicina Experimental (IBYME-CONICET), Buenos Aires, Argentina
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Li M, Usui N, Shimada S. Prenatal Sex Hormone Exposure Is Associated with the Development of Autism Spectrum Disorder. Int J Mol Sci 2023; 24:ijms24032203. [PMID: 36768521 PMCID: PMC9916422 DOI: 10.3390/ijms24032203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 01/25/2023] Open
Abstract
Sexual differentiation is a major developmental process. Sex differences resulting from sexual differentiation have attracted the attention of researchers. Unraveling what contributes to and underlies sex differences will provide valuable insights into the development of neurodevelopmental disorders that exhibit sex biases. Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects an individual's social interaction and communication abilities, and its male preponderance has been consistently reported in clinical studies. The etiology of male preponderance remains unclear, but progress has been made in studying prenatal sex hormone exposure. The present review examined studies that focused on the association between prenatal testosterone exposure and ASD development, as well as sex-specific behaviors in individuals with ASD. This review also included studies on maternal immune activation-induced developmental abnormalities that also showed striking sex differences in offspring and discussed its possible interacting roles in ASD so as to present a potential approach for future studies on sex biases in ASD.
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Affiliation(s)
- Mengwei Li
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita 565-0871, Japan
| | - Noriyoshi Usui
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita 565-0871, Japan
- United Graduate School of Child Development, Osaka University, Suita 565-0871, Japan
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka 541-8567, Japan
- Correspondence: ; Tel.: +81-6-6879-3124
| | - Shoichi Shimada
- Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Suita 565-0871, Japan
- United Graduate School of Child Development, Osaka University, Suita 565-0871, Japan
- Global Center for Medical Engineering and Informatics, Osaka University, Suita 565-0871, Japan
- Addiction Research Unit, Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Osaka 541-8567, Japan
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3
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Ipulan-Colet LA. Sexual dimorphism through androgen signaling; from external genitalia to muscles. Front Endocrinol (Lausanne) 2022; 13:940229. [PMID: 35983512 PMCID: PMC9379613 DOI: 10.3389/fendo.2022.940229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Sexual dimorphisms can be seen in many organisms with some exhibiting subtle differences while some can be very evident. The difference between male and female can be seen on the morphological level such as discrepancies in body mass, presence of body hair in distinct places, or through the presence of specific reproductive structures. It is known that the development of the reproductive structures is governed by hormone signaling, most commonly explained through the actions of androgen signaling. The developmental program of the male and female external genitalia involves a common anlage, the genital tubercle or GT, that later on develop into a penis and clitoris, respectively. Androgen signaling involvement can be seen in the different tissues in the GT that express Androgen receptor and the different genes that are regulated by androgen in the mesenchyme and endoderm component of the GT. Muscles are also known to be responsive to androgen signaling with male and female muscles exhibiting different capabilities. However, the occurrence of sexual dimorphism in muscle development is unclear. In this minireview, a summary on the role of androgen in the sexually dimorphic development of the genital tubercle was provided. This was used as a framework on analyzing the different mechanism employed by androgen signaling to regulate the sexual dimorphism in muscle development.
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Development of a putative adverse outcome pathway network for male rat reproductive tract abnormalities with specific considerations for the androgen sensitive window of development. Curr Res Toxicol 2021; 2:254-271. [PMID: 34401750 PMCID: PMC8350458 DOI: 10.1016/j.crtox.2021.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 02/06/2023] Open
Abstract
Structured approaches like the adverse outcome pathway (AOP) framework offer great potential for depicting complex toxicological processes in a manner that can facilitate informed integration of mechanistic information in regulatory decisions. While this concept provides a structure for organizing evidence and facilitates consistency in evidence integration; the process, inputs, and manner in which AOPs and AOP networks are developed is still evolving. Following the OECD guiding principles of AOP development, we propose three AOPs for male reproductive tract abnormalities and derive a putative AOP network. The AOPs were developed using a fundamental understanding of the developmental biology of the organs of interest, paying close attention to the gestational timing of key events (KEs) to very specifically inform the domain of life stage applicability for the key event relationships (KERs). Chemical stressor data primarily from studies on low molecular weight phthalates (LMWPs) served to 'bound' the pathways of focus in this dynamic period of development and were integrated with the developmental biology data through an iterative process to define KEs and conclude on the extent of evidence in support of the KERs. The AOPs developed describe the linkage between 1) a decrease in Insl3 gene expression and cryptorchidism, 2) the sustained expression of Coup-tfII and hypospadias and 3) the sustained expression of Coup-tfII and altered Wolffian duct development/ epididymal agenesis. A putative AOP network linking AOP2 and AOP3 through decreased steroidogenic biosynthetic protein expression and converging of all AOPS at the population level impaired fertility adverse outcome is proposed. The network depiction specifies and displays the KEs aligned with their occurrence in gestational time. The pathways and network described herein are intended to catalyze collaborative initiatives for expansion into a larger network to enable effective data collection and inform alternative approaches for identifying stressors impacting this sensitive period of male reproductive tract development.
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Key Words
- AGD, Anogenital distance
- AO, Adverse Outcome
- AOP, Adverse Outcome Pathway
- Adverse outcome pathway
- Adverse outcome pathway network
- DBP, Dibutyl phthalate
- DEHP, Di(2-ethylhexyl)phthalate
- DHT, 5α-dihydrotestosterone
- DPP, Dipentyl phthalate
- E, Embryonic day (ED1=GD1 gestational day 1)
- GD, Gestational day (GD1=ED1 embryonic day 1)
- KE, Key event
- KER, Key event relationship
- LMWP, low molecular weight phthalate straight chain length of the esterified alcohols between 3 and 6 carbon atoms
- MPW, male programming window
- Male programming window
- Phthalate
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5
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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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Hyuga T, Alcantara M, Kajioka D, Haraguchi R, Suzuki K, Miyagawa S, Kojima Y, Hayashi Y, Yamada G. Hedgehog Signaling for Urogenital Organogenesis and Prostate Cancer: An Implication for the Epithelial-Mesenchyme Interaction (EMI). Int J Mol Sci 2019; 21:ijms21010058. [PMID: 31861793 PMCID: PMC6982176 DOI: 10.3390/ijms21010058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/18/2019] [Accepted: 12/18/2019] [Indexed: 12/14/2022] Open
Abstract
Hedgehog (Hh) signaling is an essential growth factor signaling pathway especially in the regulation of epithelial-mesenchymal interactions (EMI) during the development of the urogenital organs such as the bladder and the external genitalia (EXG). The Hh ligands are often expressed in the epithelia, affecting the surrounding mesenchyme, and thus constituting a form of paracrine signaling. The development of the urogenital organ, therefore, provides an intriguing opportunity to study EMI and its relationship with other pathways, such as hormonal signaling. Cellular interactions of prostate cancer (PCa) with its neighboring tissue is also noteworthy. The local microenvironment, including the bone metastatic site, can release cellular signals which can affect the malignant tumors, and vice versa. Thus, it is necessary to compare possible similarities and divergences in Hh signaling functions and its interaction with other local growth factors, such as BMP (bone morphogenetic protein) between organogenesis and tumorigenesis. Additionally, this review will discuss two pertinent research aspects of Hh signaling: (1) the potential signaling crosstalk between Hh and androgen signaling; and (2) the effect of signaling between the epithelia and the mesenchyme on the status of the basement membrane with extracellular matrix structures located on the epithelial-mesenchymal interface.
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Affiliation(s)
- Taiju Hyuga
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan; (T.H.); (M.A.); (D.K.); (K.S.)
| | - Mellissa Alcantara
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan; (T.H.); (M.A.); (D.K.); (K.S.)
| | - Daiki Kajioka
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan; (T.H.); (M.A.); (D.K.); (K.S.)
| | - Ryuma Haraguchi
- Department of Molecular Pathology, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime 791-0295, Japan;
| | - Kentaro Suzuki
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan; (T.H.); (M.A.); (D.K.); (K.S.)
| | - Shinichi Miyagawa
- Department of Biological Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo 125-8585, Japan;
| | - Yoshiyuki Kojima
- Department of Urology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima 960-1295, Japan;
| | - Yutaro Hayashi
- Department of Pediatric Urology, Nagoya City University, Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan;
| | - Gen Yamada
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan; (T.H.); (M.A.); (D.K.); (K.S.)
- Correspondence: ; Tel.: +81-73-441-0849; Fax: +81-73-499-5026
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Hashimoto D, Hyuga T, Acebedo AR, Alcantara MC, Suzuki K, Yamada G. Developmental mutant mouse models for external genitalia formation. Congenit Anom (Kyoto) 2019; 59:74-80. [PMID: 30554442 DOI: 10.1111/cga.12319] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/07/2018] [Accepted: 11/14/2018] [Indexed: 02/06/2023]
Abstract
Development of external genitalia and perineum is the subject of developmental biology as well as toxicology and teratology researches. Cloaca forms in the lower (caudal) end of endoderm. Such endodermal epithelia and surrounding mesenchyme interact with various signals to form the external genitalia. External genitalia (the anlage termed as genital tubercle: GT) formation shows prominent sexually dimorphic morphogenesis in late embryonic stages, which is an unexplored developmental research field because of many reasons. External genitalia develop adjacent to the cloaca which develops urethra and corporal bodies. Developmental regulators including growth factor signals are necessary for epithelia-mesenchyme interaction (EMI) in posterior embryos including the cloaca and urethra in the genitalia. In the case of male type urethra, formation of tubular urethra proceeds from the lower (ventral) side of external genitalia as a masculinization process in contrast to the case of female urethra. Mechanisms for its development are not elucidated yet due to the lack of suitable mutant mouse models. Because of the recent progresses of Cre (recombinase)-mediated conditional target gene modification analyses, many developmental regulatory genes become increasingly analyzed. Conditional gene knockout mouse approaches and tissue lineage approaches are expected to offer vital information for such sexually dimorphic developmental processes. This review aims to offer recent updates on the progresses of these emerging developmental processes for the research field of congenital anomalies.
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Affiliation(s)
- Daiki Hashimoto
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | - Taiju Hyuga
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | - Alvin R Acebedo
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | - Mellissa C Alcantara
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | - Kentaro Suzuki
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
| | - Gen Yamada
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University (WMU), Wakayama, Japan
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8
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Regulation of masculinization: androgen signalling for external genitalia development. Nat Rev Urol 2018; 15:358-368. [DOI: 10.1038/s41585-018-0008-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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9
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Dos Santos AC, Conley AJ, de Oliveira MF, de Assis Neto AC. Development of urogenital system in the Spix cavy: A model for studies on sexual differentiation. Differentiation 2018; 101:25-38. [PMID: 29684807 DOI: 10.1016/j.diff.2018.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 04/04/2018] [Accepted: 04/11/2018] [Indexed: 12/17/2022]
Abstract
This study documented, for the first time, the morphological patterns of differentiation of male and female genital organs of Spix cavy (Galea spixii) using histological and ultrastructural analyses, with immuno-localization of steroidogenic enzymes, cytochromes P450 aromatase (P450arom) and 17α-hydroxylase/17, 20-lyase (P450c17), involved in the synthesis of estrogens and androgens respectively throughout fetal sexual development. Undifferentiated gonads of Spix cavy develop into ovaries in females after 25 days of gestation (DG), exhibiting P450arom immunoreactivity. After 25 DG, paramesonephric ducts develop and form oviducts, uterine horns and cranial portion of the vagina. The caudal portion of the vagina originates from the urogenital sinus, and a vaginal closure membrane is present at the end of gestation. Partial channeling of the urethra into the clitoris occurs after 40 DG, but complete channeling never occurs. A preputial meatus emerges near the tip of organ. In males, undifferentiated gonads develop into testes at 25 DG and develop immunoreactivity for P450c17, which is required for androgens synthesis and likely maintenance of mesonephric ducts. Mesonephric ducts develop subsequently, forming the epididymis and ductus deferens. The pelvic urethra develops after 25 DG with channeling into the penis occurring around 30 DG. This is the first morphological study describing the process of sexual differentiation during gestation in a hystricomorph rodent and one of the most comprehensive analyses conducted in any mammal. Male genital organ development follows the general pattern described in other domestic mammals, but does not include formation of the baculum as occurs in mice and rats. In females, clitoral development includes partial canalization by the urethra and development of a preputial meatus. Further studies are required to clarify the mechanisms involved in the differentiative processes described.
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Affiliation(s)
- Amilton Cesar Dos Santos
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87 ZC, 05508-270 São Paulo-SP, Brazil
| | - Alan James Conley
- Population Health&Reproduction, School of Veterinary Medicine, University of California, Davis, USA
| | | | - Antônio Chaves de Assis Neto
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87 ZC, 05508-270 São Paulo-SP, Brazil.
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10
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Miyado M, Miyado K, Nakamura A, Fukami M, Yamada G, Oda SI. Expression patterns of Fgf8 and Shh in the developing external genitalia of Suncus murinus. Reproduction 2017; 153:187-195. [DOI: 10.1530/rep-16-0231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 01/23/2023]
Abstract
Reciprocal epithelial–mesenchymal interactions and several signalling pathways regulate the development of the genital tubercle (GT), an embryonic primordium of external genitalia. The morphology of the adult male external genitalia of the Asian house musk shrew Suncus murinus (hereafter, laboratory name: suncus) belonging to the order Eulipotyphla (the former order Insectivora or Soricomorpha) differs from those of mice and humans. However, the developmental process of the suncus GT and its regulatory genes are unknown. In the present study, we explored the morphological changes and gene expression patterns during the development of the suncus GT. Morphological observations suggested the presence of common (during the initial outgrowth) and species-specific (during the sexual differentiation of GT) developmental processes of the suncus GT. In gene expression analysis, fibroblast growth factor 8 (Fgf8) and sonic hedgehog (Shh), an indicator and regulator of GT development in mice respectively, were found to be expressed in the cloacal epithelium and the developing urethral epithelium of the suncus GT. This pattern of expression specifically in GT epithelium is similar to that observed in the developing mouse GT. Our results indicate that the mechanism of GT formation regulated by the FGF and SHH signalling pathways is widely conserved in mammals.
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Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina. Proc Natl Acad Sci U S A 2016; 113:E7510-E7517. [PMID: 27821748 DOI: 10.1073/pnas.1610471113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development.
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