scholarly journals DDB1 Regulates Sertoli Cell Proliferation and Testis Cord Remodeling by TGFβ Pathway

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 974
Author(s):  
Wei Zheng ◽  
Jabeen Nazish ◽  
Fazal Wahab ◽  
Ranjha Khan ◽  
Xiaohua Jiang ◽  
...  

Testis cords are the embryonic precursors of the seminiferous tubules. Development of testis cords is a key event during embryonic testicular morphogenesis and is regulated by multiple signaling molecules produced by Sertoli cells. However, the exact nature and the cascade of molecular events underlying testis cord development remain to be uncovered. In the current study, we explored the role of DNA damage binding protein 1 (DDB1) in Sertoli cells during mouse testis cord development. The genetic ablation of Ddb1 specifically in Sertoli cells resulted in the compromised Sertoli cell proliferation and disruption of testis cord remodeling in neonatal mice. This testicular dysgenesis persisted through adulthood, resulting in smaller testis and low sperm production. Mechanistically, we observed that the DDB1 degradation can stabilize SET domain-containing lysine methyltransferase 8 (SET8), which subsequently decreases the phosphorylation of SMAD2, an essential intracellular component of transforming growth factor beta (TGFβ) signaling. Taken together, our results suggest an essential role of Ddb1 in Sertoli cell proliferation and normal remodeling of testis cords via TGFβ pathway. To our knowledge, this is the first upstream regulators of TGFβ pathway in Sertoli cells, and therefore it furthers our understanding of testis cord development.

2021 ◽  
Vol 12 ◽  
Author(s):  
Wasim Shah ◽  
Ranjha Khan ◽  
Basit Shah ◽  
Asad Khan ◽  
Sobia Dil ◽  
...  

Sustaining and maintaining the intricate process of spermatogenesis is liable upon hormones and growth factors acting through endocrine and paracrine pathways. The Sertoli cells (SCs) are the major somatic cells present in the seminiferous tubules and are considered to be the main regulators of spermatogenesis. As each Sertoli cell supports a specific number of germ cells, thus, the final number of Sertoli cells determines the sperm production capacity. Similarly, sex hormones are also major regulators of spermatogenesis and they can determine the proliferation of Sertoli cells. In the present review, we have critically and comprehensively discussed the role of sex hormones and some other factors that are involved in Sertoli cell proliferation, differentiation and maturation. Furthermore, we have also presented a model of Sertoli cell development based upon the recent advancement in the field of reproduction. Hence, our review article provides a general overview regarding the sex hormonal pathways governing Sertoli cell proliferation and development.


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

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.


Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1691
Author(s):  
Rong-Ge Yan ◽  
Qi-Lin Yang ◽  
Qi-En Yang

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.


1995 ◽  
Vol 145 (2) ◽  
pp. 355-362 ◽  
Author(s):  
S Palmero ◽  
M Prati ◽  
F Bolla ◽  
E Fugassa

Abstract The addition of physiological concentrations (1 nm) of tri-iodothyronine (T3) to the culture medium of Sertoli cells from prepubertal (8-day-old) rats stimulated both protein synthesis (+55%) and lactate (+50%) production, while it inhibited DNA synthesis (−30/35%) and aromatase activity (−45/50%); insignificant T3-dependent effects were observed in cultured Sertoli cells from midpubertal (28-day-old) rats. These data suggest an age-dependent role for thyroid hormone in promoting and maintaining Sertoli cell differentiation at puberty; moreover, the hormone is involved in the regulation of Sertoli cell proliferation. The present study validates the role of Sertoli cells as a specific target for T3 action at the testis level; it also demonstrates the existence of an early and critical direct influence of thyroid hormone on Sertoli cell proliferation and functional maturation. Journal of Endocrinology (1995) 145, 355–362


Reproduction ◽  
2020 ◽  
Vol 159 (2) ◽  
pp. 145-157 ◽  
Author(s):  
Hu Gao ◽  
Bin Chen ◽  
Hui Luo ◽  
Bo Weng ◽  
Xiangwei Tang ◽  
...  

Sertoli cells are indispensable for normal spermatogenesis, and increasing evidence has shown that miRNAs participate in the regulation of Sertoli cell growth. However, the functions and regulatory mechanisms of miRNAs in Sertoli cells of domestic animals have not been fully investigated. In the present study, we mainly investigated the regulatory roles of miR-499 in immature porcine Sertoli cells. The results showed that miR-499 was mainly located in the basement section of seminiferous tubules of prepubertal porcine testicular tissue. Overexpression of miR-499 promoted cell proliferation and inhibited apoptosis, whereas miR-499 inhibition resulted in the opposite effect. The PTEN gene was directly targeted by miR-499, and the expression of mRNA and protein was also negatively regulated by miR-499 in immature porcine Sertoli cells. siRNA-induced PTEN knockdown resulted in a similar effect as an overexpression of miR-499 and abolished the effects of miR-499 inhibition on immature porcine Sertoli cells. Moreover, both miR-499 overexpression and the PTEN knockdown activated the PI3K/AKT signaling pathway, whereas inhibition of the PI3K/AKT signaling pathway caused immature porcine Sertoli cell apoptosis and inhibited cell proliferation. Overall, miR-499 promotes proliferation and inhibits apoptosis in immature porcine Sertoli cells through the PI3K/AKT pathway by targeting the PTEN gene. This study provides novel insights into the effects of miR-499 in spermatogenesis through the regulation of immature Sertoli cell proliferation and apoptosis.


2004 ◽  
Vol 16 (9) ◽  
pp. 127
Author(s):  
A. J. Beardsley ◽  
D. M. Robertson ◽  
L. O'Donnell

Spermiation is the final step of spermatogenesis (sperm production) where mature spermatids are released from the somatic Sertoli cells. Spermiation is hormone sensitive; testosterone (T) and FSH withdrawal causes a disruption to the disengagement of spermatids, which are instead retained by Sertoli cells. The mechanisms involved with spermatid release and retention are not understood. We showed previously that an unknown adhesion junction containing β1-integrin persisted on retained spermatids suggesting that a defect in this adhesion complex at disengagement may underlie spermiation failure. The aim of this study is to identify the α-integrin dimerised with β1-integrin and investigate the role of phosphorylated FAK, a kinase that is involved with integrin-mediated cell adhesion, during spermiation and spermiation failure. Four adult Sprague-Dawley rats received T and oestradiol implants and FSH antibody for 7A days to suppress testicular T and FSH and induce spermiation failure. Using immunohistochemistry, α6-integrin (but not α4-integrin) and FAK-Tyr397 were localised on the Sertoli cell plasma membrane adjacent to mature spermatids. This localisation was observed until the point of spermatid release and remained on the Sertoli cell that surrounded retained spermatids after hormone suppression. A similar localisation has been previously observed with β1-integrin, suggesting that all three form a complex at the site of disengagement. To look at the function of FAK-Tyr397, comparative Western blot analysis is currently being undertaken on seminiferous tubules specific for spermiation from control and treated animals. Preliminary studies suggest that FAK-Tyr397 remains phosphorylated during spermiation failure, suggesting that FAK dephosphorylation may be important for the function of spermatid-associated adhesion complexes, as has been demonstrated in other adhesion systems. In conclusion, α6β1-integrin/FAK-containing adhesion complexes are associated with spermatids during spermiation, and the function of such complexes are likely to be perturbed during spermiation failure.


2020 ◽  
Vol 32 (10) ◽  
pp. 929
Author(s):  
Chinju Johnson ◽  
John Kastelic ◽  
Jacob Thundathil

The critical role of insulin-like growth factor (IGF) 1 in promoting Sertoli cell proliferation invivo and invitro has been established, but its downstream signalling mechanisms remain unknown. In addition to mitogenic effects, a role for IGF1 in mediating cholesterol biosynthesis within testes has been implied. The aims of this study were to investigate the roles of: (1) phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) signalling in IGF1-mediated Sertoli cell proliferation; and (2) IGF1 in mediating cholesterol biosynthesis in Sertoli cells. Primary cultures of Sertoli cells were prepared from 1-week-old porcine testes. On Day 3 of culture, Sertoli cells were treated with 300ng mL−1 IGF1, alone or in combination with inhibitors of IGF1 receptor (2μM picropodophyllotoxin), Akt (1μM wortmannin) or mTOR (200nM rapamycin). Cells were cultured for 30min and phosphorylation levels of Akt, mTOR and p70 ribosomal protein S6 kinase (p70S6K) were determined by immunoblotting. Cell proliferation and quantitative polymerase chain reaction assays were conducted using cells cultured for 24h. IGF1 increased phosphorylation of Akt, mTOR and p70S6K and cell proliferation, and these effects were inhibited by inhibitors of IGF1R, Akt and mTOR. Furthermore, IGF1 upregulated the expression of cholesterol biosynthetic genes (3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS1) and cytochrome P450, family 5, subfamily A, polypeptide 1 (CYP5A1)), but not sterol regulatory element-binding transcription factor 1 (SREBF1). Increased phosphorylation of p70S6K, a major downstream target of mTOR, and upregulated expression of genes involved in cholesterol biosynthesis are indicative of the key role played by IGF1 in regulating the synthesis of cholesterol, the precursor for steroid hormones.


2021 ◽  
pp. 1-14
Author(s):  
Yuanyuan Li ◽  
Jinbo Li ◽  
Man Cai ◽  
Zhanfen Qin

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.


Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1759-1766 ◽  
Author(s):  
K. Yomogida ◽  
H. Ohtani ◽  
H. Harigae ◽  
E. Ito ◽  
Y. Nishimune ◽  
...  

GATA-1 is an essential factor for the transcriptional activation of erythroid-specific genes, and is also abundantly expressed in a discrete subset of cells bordering the seminiferous epithelium in tubules of the murine testis. In examining normal and germ-line defective mutant mice, we show here that GATA-1 is expressed only in the Sertoli cell lineage in mouse testis. GATA-1 expression in Sertoli cells is induced concomitantly with the first wave of spermatogenesis, and GATA-1-positive cells are uniformly distributed among all tubules during prepubertal testis development. However, the number of GATA-1-positive cells declines thereafter and were found only in the peripheral zone of seminiferous tubules in stages VII, VIII and IX of spermatogenesis in the adult mouse testis. In contrast, virtually every Sertoli cell in mutant W/Wv, jsd/jsd or cryptorchid mice (all of which lack significant numbers of germ cells) expresses GATA-1, thus showing that the expression of this transcription factor is negatively controlled by the maturing germ cells. These observations suggest that transcription factor GATA-1 is a developmental stage- and spermatogenic cycle-specific regulator of gene expression in Sertoli cells.


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