149. Smad3 DOSAGE INFLUENCES TESTICULAR MATURATION

2009 ◽  
Vol 21 (9) ◽  
pp. 67
Author(s):  
C. Itman ◽  
C. Wong ◽  
D. A. Jans ◽  
M. Ernst ◽  
K. L. Loveland
Keyword(s):  
Cell Proliferation ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Post Partum ◽  
Cell Maturation ◽  
Physiological Status ◽  
Testis Weight ◽  
Testis Development ◽  
Smad3 Expression ◽  
Cell Mitogen

Activin A, a TGF-beta superfamily ligand which signals via Smad2 and Smad3, is critical for normal mouse testis development and quantitatively normal sperm production. Whereas activin enhances immature Sertoli cell proliferation (1), excessive activin production causes Sertoli cell tumours (2); this is alleviated when mice lack Smad3 (3). Sertoli cells exhibit developmentally regulated Smad utilization in activin signalling. Immature Sertoli cells signal via Smad3 while the onset of Smad2-mediated signal transduction correlates with Sertoli cell maturation (4). This change coincides with decreased testicular Smad3 production at puberty and a shift in follicle stimulating hormone (FSH)-induced Smad transcription, from Smad3 in 6 dpp (days post partum) Sertoli cells to Smad2 in 15 dpp cells. These findings suggest that Smad3 is more important for testis development than adult spermatogenesis. To test this hypothesis, we examined testis development in Smad3+/– and Smad3–/– mice. At 7 dpp, testis weight and cord diameter were reduced in Smad3–/–mice, indicating impaired Sertoli cell proliferation. Levels of FSH, a potent Sertoli cell mitogen, were unaltered. Histological analysis revealed advanced spermatogenesis in heterozygous mice, with round spermatids already present at 16 dpp. Quantitative PCR also identified advanced Sertoli and germ cell maturation in Smad3+/– mice, while Leydig cell maturation appeared unaltered. Adult Smad3+/– and Smad3–/– mice were fertile, but had smaller testes. This is the first study relating Smad3 levels to puberty onset and identifies the Smad3+/– mouse as a model of peripheral precocious puberty with otherwise normal physiological status, i.e. no gonadal tumours and normal FSH levels. These results demonstrate that FSH influences testis growth and maturation by regulating Smad3 expression and highlights the importance of testing whether environmental factors, toxicants and endocrine disruptors affect Smad3 expression, thereby leading to altered testis development.

Signal transduction pathways in FSH regulation of rat Sertoli cell proliferation

2012 ◽  
Vol 302 (8) ◽  
pp. E914-E923 ◽  
Author(s):  
María F. Riera ◽  
Mariana Regueira ◽  
María N. Galardo ◽  
Eliana H. Pellizzari ◽  
Silvina B. Meroni ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Kinase Inhibitors ◽  
Production Capacity ◽  
Signal Transduction Pathways ◽  
Mtorc1 Signaling ◽  
Mtorc1 Pathway ◽  
Cell Mitogen

The final number of Sertoli cells reached during the proliferative periods determines sperm production capacity in adulthood. It is well known that FSH is the major Sertoli cell mitogen; however, little is known about the signal transduction pathways that regulate the proliferation of Sertoli cells. The hypothesis of this investigation was that FSH regulates proliferation through a PI3K/Akt/mTORC1 pathway, and additionally, AMPK-dependent mechanisms counteract FSH proliferative effects. The present study was performed in 8-day-old rat Sertoli cell cultures. The results presented herein show that FSH, in addition to increasing p-Akt, p-mTOR, and p-p70S6K levels, increases p-PRAS40 levels, probably contributing to improving mTORC1 signaling. Furthermore, the decrease in FSH-stimulated p-Akt, p-mTOR, p-p70S6K, and p-PRAS40 levels in the presence of wortmannin emphasizes the participation of PI3K in FSH signaling. Additionally, the inhibition of FSH-stimulated Sertoli cell proliferation by the effect of wortmannin and rapamycin point to the relevance of the PI3K/Akt/mTORC1 signaling pathway in the mitotic activity of FSH. On the other hand, by activating AMPK, several interesting observations were made. Activation of AMPK produced an increase in Raptor phosphorylation, a decrease in p70S6K phosphorylation, and a decrease in FSH-stimulated Sertoli cell proliferation. The decrease in FSH-stimulated cell proliferation was accompanied by an increased expression of the cyclin-dependent kinase inhibitors (CDKIs) p19INK4d, p21Cip1, and p27Kip1. In summary, it is concluded that FSH regulates Sertoli cell proliferation with the participation of a PI3K/Akt/mTORC1 pathway and that AMPK activation may be involved in the detention of proliferation by, at least in part, a decrease in mTORC1 signaling and an increase in CDKI expression.

scholarly journals Metformin counteracts the effects of FSH on rat Sertoli cell proliferation

Reproduction ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. 93-101 ◽  
Author(s):  
Gustavo Marcelo Rindone ◽  
Agostina Gorga ◽  
Mariana Regueira ◽  
Eliana Herminia Pellizzari ◽  
Selva Beatriz Cigorraga ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Molecular Mechanisms ◽  
Pediatric Population ◽  
Follicle Stimulating Hormone ◽  
Acetyl Coa Carboxylase ◽  
Cell Cycle Inhibitor ◽  
Cell Mitogen

Metformin (MET) is one of the most widely used anti-hyperglycemic agents for treating patients with type 2 diabetes and it has started to be used in pediatric population at ages when Sertoli cells are still proliferating. It is well known that follicle-stimulating hormone (FSH) is the major Sertoli cell mitogen. The aim of the study is to investigate a possible effect of MET, which has been shown to have anti-proliferative properties, on FSH regulation of postnatal Sertoli cell proliferation and on the molecular mechanisms involved in this regulation. The present study was performed in eight-day-old rat Sertoli cell cultures. The results obtained show that MET in the presence of FSH increases phosphorylated acetyl-CoA carboxylase and decreases phosphorylated p70S6K levels. Moreover, we show that MET decreases FSH-stimulated Sertoli cell proliferation, and this decrease is accompanied by a reduction in FSH-stimulated Ccnd1 and Ccnd2 expression and an increase in cell cycle inhibitor p21Cip expression. Altogether, these results suggest that MET can, at least in part, counteract the effect of FSH on postnatal Sertoli cell proliferation.

Development of Testis Cords and the Formation of Efferent Ducts in Xenopus laevis: Differences and Similarities with Other Vertebrates

2021 ◽  
pp. 1-14
Author(s):  
Yuanyuan Li ◽  
Jinbo Li ◽  
Man Cai ◽  
Zhanfen Qin
Keyword(s):  
Cell Proliferation ◽  
Xenopus Laevis ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Testis Development ◽  
Larval Stages ◽  
Efferent Ducts ◽  
Steroidogenic Cells ◽  
Testis Cord ◽  
Anterior Posterior

The knowledge of testis development in amphibians relative to amniotes remains limited. Here, we used Xenopus laevis to investigate the process of testis cord development. Morphological observations revealed the presence of segmental gonomeres consisting of medullary knots in male gonads at stages 52–53, with no distinct gonomeres in female gonads. Further observations showed that cell proliferation occurs at specific sites along the anterior-posterior axis of the future testis at stage 50, which contributes to the formation of medullary knots. At stage 53, adjacent gonomeres become close to each other, resulting in fusion; then (pre-)Sertoli cells aggregate and form primitive testis cords, which ultimately become testis cords when germ cells are present inside. The process of testis cord formation in X. laevis appears to be more complex than in amniotes. Strikingly, steroidogenic cells appear earlier than (pre-)Sertoli cells in differentiating testes of X. laevis, which differs from earlier differentiation of (pre-)Sertoli cells in amniotes. Importantly, we found that the mesonephros is connected to the testis gonomere at a specific site at early larval stages and that these connections become efferent ducts after metamorphosis, which challenges the previous concept that the mesonephric side and the gonadal side initially develop in isolation and then connect to each other in amphibians and amniotes.

scholarly journals Smad3 Dosage Determines Androgen Responsiveness and Sets the Pace of Postnatal Testis Development

Endocrinology ◽  
2011 ◽  
Vol 152 (5) ◽  
pp. 2076-2089 ◽  
Author(s):  
Catherine Itman ◽  
Chin Wong ◽  
Briony Hunyadi ◽  
Matthias Ernst ◽  
David A. Jans ◽  
...  
Keyword(s):  
Germ Cell ◽  
Sertoli Cell ◽  
Pubertal Development ◽  
Cell Development ◽  
Cell Maturation ◽  
Developmentally Regulated ◽  
Testis Development ◽  
Essentially Normal ◽  
Endocrine Factors ◽  
Immature Cells

The establishment and maturation of the testicular Sertoli cell population underpins adult male fertility. These events are influenced by hormones and endocrine factors, including FSH, testosterone and activin. Activin A has developmentally regulated effects on Sertoli cells, enhancing proliferation of immature cells and later promoting postmitotic maturation. These differential responses correlate with altered mothers against decapentaplegic (SMAD)-2/3 signaling: immature cells signal via SMAD3, whereas postmitotic cells use both SMAD2 and SMAD3. This study examined the contribution of SMAD3 to postnatal mouse testis development. We show that SMAD3 production and subcellular localization are highly regulated and, through histological and molecular analyses, identify effects of altered Smad3 dosage on Sertoli and germ cell development. Smad3+/− and Smad3−/− mice had smaller testes at 7 d postpartum, but this was not sustained into adulthood. Juvenile and adult serum FSH levels were unaffected by genotype. Smad3-null mice displayed delayed Sertoli cell maturation and had reduced expression of androgen receptor (AR), androgen-regulated transcripts, and Smad2, whereas germ cell and Leydig cell development were essentially normal. This contrasted remarkably with advanced Sertoli and germ cell maturation and increased expression of AR and androgen-regulated transcripts in Smad3+/− mice. In addition, SMAD3 was down-regulated during testis development and testosterone up-regulated Smad2, but not Smad3, in the TM4 Sertoli cell line. Collectively these data reveal that appropriate SMAD3-mediated signaling drives normal Sertoli cell proliferation, androgen responsiveness, and maturation and influences the pace of the first wave of spermatogenesis, providing new clues to causes of altered pubertal development in boys.

scholarly journals Testicular Somatic Cells, not Gonocytes, Are the Major Source of Functional Activin A during Testis Morphogenesis

Endocrinology ◽  
2011 ◽  
Vol 152 (11) ◽  
pp. 4358-4367 ◽  
Author(s):  
Denise R. Archambeault ◽  
Jessica Tomaszewski ◽  
Andrew J. Childs ◽  
Richard A. Anderson ◽  
Humphrey Hung-Chang Yao
Keyword(s):  
Cell Proliferation ◽  
Sertoli Cell ◽  
Somatic Cells ◽  
Activin A ◽  
Protein Product ◽  
Conditional Knockout ◽  
Seminiferous Tubules ◽  
Testis Size ◽  
Testis Development ◽  
Testis Cord

Proper development of the seminiferous tubules (or testis cords in embryos) is critical for male fertility. Sertoli cells, somatic components of the seminiferous tubules, serve as nurse cells to the male germline, and thus their numbers decide the quantity of sperm output in adulthood. We previously identified activin A, the protein product of the activin βA (Inhba) gene, as a key regulator of murine Sertoli cell proliferation and testis cord expansion during embryogenesis. Although our genetic studies implicated fetal Leydig cells as the primary producers of testicular activin A, gonocytes are another potential source. To investigate the relative contribution of gonocyte-derived activin A to testis morphogenesis, we compared testis development in the Inhba global knockout mouse, which lacks activin A production in all cells (including the gonocytes), and a steroidogenic factor 1 (Sf1)-specific conditional knockout model in which activin A expression in testicular somatic cells is disrupted but gonocyte expression of activin A remains intact. Surprisingly, testis development was comparable in these two models of activin A insufficiency, with similar reductions in Sertoli cell proliferation and minor differences in testis histology. Thus, our findings suggest activin A from male gonocytes is insufficient to promote Sertoli cell proliferation and testis cord expansion in the absence of somatic cell-derived activin A. Evaluation of adult male mice with fetal disruption of activin A revealed reduced testis size, lowered sperm production, altered testicular histology, and elevated plasma FSH levels, defects reminiscent of human cases of androgen-sufficient idiopathic oligozoospermia.

scholarly journals Exogenous Gonadotrophin Stimulation Induces Partial Maturation of Human Sertoli Cells in a Testicular Xenotransplantation Model for Fertility Preservation

2020 ◽  
Vol 9 (1) ◽  
pp. 266 ◽  
Author(s):  
Marsida Hutka ◽  
Lee B. Smith ◽  
Ellen Goossens ◽  
W. Hamish B. Wallace ◽  
Jan-Bernd Stukenborg ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Connexin 43 ◽  
Xenograft Model ◽  
Cell Maturation ◽  
Human Testis ◽  
Testicular Development ◽  
Future Fertility ◽  
And Function ◽  
Testis Tissue

The future fertility of prepubertal boys with cancer may be irreversibly compromised by chemotherapy and/or radiotherapy. Successful spermatogenesis has not been achieved following the xenotransplantation of prepubertal human testis tissue, which is likely due to the failure of somatic cell maturation and function. We used a validated xenograft model to identify the factors required for Leydig and Sertoli cell development and function in immature human testis. Importantly, we compared the maturation status of Sertoli cells in xenografts with that of human testis tissues (n = 9, 1 year-adult). Human fetal testis (n = 6; 14–21 gestational weeks) tissue, which models many aspects of prepubertal testicular development, was transplanted subcutaneously into castrated immunocompromised mice for ~12 months. The mice received exogenous human chorionic gonadotropin (hCG; 20IU, 3×/week). In xenografts exposed continuously to hCG, we demonstrate the maintenance of Leydig cell steroidogenesis, the acquisition of features of Sertoli cell maturation (androgen receptor, lumen development), and the formation of the blood–testis barrier (connexin 43), none of which were present prior to the transplantation or in xenografts in which hCG was withdrawn after 7 months. These studies provide evidence that hCG plays a role in Sertoli cell maturation, which is relevant for future investigations, helping them generate functional gametes from immature testis tissue for clinical application.

scholarly journals Morphological changes of Sertoli cells during the male reproductive cycle of the teleost Piaractus mesopotamicus (Holmberg, 1887)

2005 ◽  
Vol 65 (2) ◽  
pp. 241-249 ◽  
Author(s):  
C. Cruz-Landim ◽  
F. C. Abdalla ◽  
M. A. Cruz-Höfling
Keyword(s):  
Germ Cell ◽  
Sertoli Cell ◽  
Reproductive Cycle ◽  
Sertoli Cells ◽  
Morphological Changes ◽  
Cell Development ◽  
Cell Maturation ◽  
Ultrastructural Changes ◽  
Piaractus Mesopotamicus

An investigation of the histological and ultrastructural changes of Sertoli cells during the male reproductive cycle in Piaractus mesopotamicus was made. The results showed that the Sertoli cell development is closely related with germ cell maturation. Therefore, these cells may have some role in germ cell maturation during the reproductive cycle of this species, whether in forming a tissue framework for the developing spermatogenic cysts, aiding in testes reorganization for a new reproductive cycle, in addition to other possible functions discussed in the text.

scholarly journals E4 Transcription Factor 1 (E4F1) Regulates Sertoli Cell Proliferation and Fertility in Mice

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1691
Author(s):  
Rong-Ge Yan ◽  
Qi-Lin Yang ◽  
Qi-En Yang
Keyword(s):  
Cell Proliferation ◽  
Transcription Factor ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Cell Function ◽  
Conditional Knockout ◽  
Seminiferous Tubules ◽  
Quiescent State ◽  
Testis Size ◽  
Cell Fate Decisions

In the mammalian testes, Sertoli cells are the only somatic cells in the seminiferous tubules that provide structural, nutritional and regulatory support for developing spermatogenic cells. Sertoli cells only proliferate during the fetal and neonatal periods and enter a quiescent state after puberty. Functional evidences suggest that the size of Sertoli cell population determines sperm production and fertility. However, factors that direct Sertoli cell proliferation and maturation are not fully understood. Transcription factor E4F1 is a multifunctional protein that serves essential roles in cell fate decisions and because it interacts with pRB, a master regulator of Sertoli cell function, we hypothesized that E4F1 may have a functional role in Sertoli cells. E4f1 mRNA was present in murine testis and immunohistochemical staining confirmed that E4F1 was enriched in mature Sertoli cells. We generated a conditional knockout mouse model using Amh-cre and E4f1flox/flox lines to study E4F1 fucntion in Sertoli cells and the results showed that E4f1 deletion caused a significant reduction in testis size and fertility. Further analyses revealed that meiosis progression and spermiogenesis were normal, however, Sertoli cell proliferation was impaired and germ cell apoptosis was elevated in the testis of E4f1 conditional knockout mice. On the basis of these findings, we concluded that E4F1 was expressed in murine Sertoli cells and served important functions in regulating Sertoli cell proliferation and fertility.

Differentiation of Fetal Sertoli Cells in the Adult Testis

Reproduction ◽  
2021 ◽  
Author(s):  
Tetsuhiro Yokonishi ◽  
Blanche Capel
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Developmental Process ◽  
Ips Cells ◽  
Cell Maturation ◽  
Seminiferous Tubules ◽  
Fetal Life ◽  
Adult Testis ◽  
Testicular Cells

Sertoli cells proliferate and construct seminiferous tubules during fetal life, then undergo differentiation and maturation in the prepubertal testes. In the adult testes, mature Sertoli cells maintain spermatogonia and support spermatogenesis during the entire lifetime. Although Sertoli-like cells have been derived from iPS cells, they tend to remain immature. To investigate whether Sertoli cells can spontaneously acquire the ability to support spermatogenesis when transferred into the adult testis, we transplanted mouse fetal testicular cells into a Sertoli-depleted adult testis. We found that donor E12.5, E14.5 and E16.5 Sertoli cells colonized adult seminiferous tubules and supported host spermatogenesis two months after transplantation, demonstrating that immature fetal Sertoli cells can undergo sufficient maturation in the adult testis to become functional. This technique will be useful to analyze the developmental process of Sertoli cell maturation, and to investigate the potential of iPS-derived Sertoli cells to colonize, undergo maturation, and support spermatogenesis within the testis environment.

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