scholarly journals Cdc42 activity in Sertoli cells is essential for maintenance of spermatogenesis

2021 ◽  
Author(s):  
Bidur Bhandary ◽  
Anna Heinrich ◽  
Sarah J. Potter ◽  
Nancy Ratner ◽  
Tony DeFalco

SUMMARYSertoli cells are highly polarized testicular supporting cells that simultaneously nurture progressively maturing germ cells. Proper localization of polarity protein complexes within Sertoli cells, including those responsible for blood-testis barrier formation, are vital for successful spermatogenesis. However, the mechanisms and developmental timing that underlie the establishment of polarity are poorly understood. To investigate this aspect of testicular function, we conditionally deleted Cdc42, encoding a Rho GTPase involved in regulating cell polarity, specifically in Sertoli cells. Cdc42 deletion disrupted adult Sertoli cell maturation and localization of polarity proteins, but did not affect fetal and early postnatal testicular development, nor the onset of the first wave of spermatogenesis. By early adulthood, however, conditional knockout males exhibited a loss of spermatogenic cells, resulting in a complete lack of sperm. These findings demonstrate that Cdc42 plays an essential role in establishing adult Sertoli cell polarity and, thus, maintaining steady-state spermatogenesis and healthy sperm production.

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4244-4256 ◽  
Author(s):  
Heling Dong ◽  
Zhenguo Chen ◽  
Caixia Wang ◽  
Zhi Xiong ◽  
Wanlu Zhao ◽  
...  

Maintenance of cell polarity is essential for Sertoli cell and blood-testis barrier (BTB) function and spermatogenesis; however, the signaling mechanisms that regulate the integrity of the cytoskeleton and polarity of Sertoli cells are not fully understood. Here, we demonstrate that rapamycin-insensitive component of target of rapamycin (TOR) (Rictor), a core component of mechanistic TOR complex 2 (mTORC2), was expressed in the seminiferous epithelium during testicular development, and was down-regulated in a cadmium chloride-induced BTB damage model. We then conditionally deleted the Rictor gene in Sertoli cells and mutant mice exhibited azoospermia and were sterile as early as 3 months old. Further study revealed that Rictor may regulate actin organization via both mTORC2-dependent and mTORC2-independent mechanisms, in which the small GTPase, ras-related C3 botulinum toxin substrate 1, and phosphorylation of the actin filament regulatory protein, Paxillin, are involved, respectively. Loss of Rictor in Sertoli cells perturbed actin dynamics and caused microtubule disarrangement, both of which accumulatively disrupted Sertoli cell polarity and BTB integrity, accompanied by testicular developmental defects, spermiogenic arrest and excessive germ cell loss in mutant mice. Together, these findings establish the importance of Rictor/mTORC2 signaling in Sertoli cell function and spermatogenesis through the maintenance of Sertoli cell cytoskeletal dynamics, BTB integrity, and cell polarity.


2020 ◽  
Vol 21 (12) ◽  
pp. 4358
Author(s):  
Shuai Wang ◽  
Pengxiang Wang ◽  
Dongli Liang ◽  
Yuan Wang

Sertoli cells are somatic supporting cells in spermatogenic niche and play critical roles in germ cell development, but it is yet to be understood how epigenetic modifiers regulate Sertoli cell development and contribution to spermatogenesis. BRG1 (Brahma related gene 1) is a catalytic subunit of the mammalian SWI/SNF chromatin remodeling complex and participates in transcriptional regulation. The present study aimed to define the functions of BRG1 in mouse Sertoli cells during mouse spermatogenesis. We found that BRG1 protein was localized in the nuclei of both Sertoli cells and germ cells in seminiferous tubules. We further examined the requirement of BRG1 in Sertoli cell development using a Brg1 conditional knockout mouse model and two Amh-Cre mouse strains to specifically delete Brg1 gene from Sertoli cells. We found that the Amh-Cre mice from Jackson Laboratory had inefficient recombinase activities in Sertoli cells, while the other Amh-Cre strain from the European Mouse Mutant Archive achieved complete Brg1 deletion in Sertoli cells. Nevertheless, the conditional knockout of Brg1 from Sertoli cells by neither of Amh-Cre strains led to any detectable abnormalities in the development of either Sertoli cells or germ cells, suggesting that BRG1-SWI/SNF complex is dispensable to the functions of Sertoli cells in spermatogenesis.


It has long been assumed that the mammalian Y chromosome either encodes, or controls the production of, a diffusible testis-determining molecule, exposure of the embryonic gonad to this molecule being all that is required to divert it along the testicular pathway. My recent finding that Sertoli cells in XX ↔ XY chimeric mouse testes are exclusively XY has led me to propose a new model in which the Y acts cell-autonomously to bring about Sertoli-cell differentiation. I have suggested that all other aspects of foetal testicular development are triggered by the Sertoli cells without further Y-chromosome involvement. This model thus equates mammalian sex determination with Sertoli-cell determination. Examples of natural and experimentally induced sex reversal are discussed in the context of this model.


2020 ◽  
Vol 9 (1) ◽  
pp. 266 ◽  
Author(s):  
Marsida Hutka ◽  
Lee B. Smith ◽  
Ellen Goossens ◽  
W. Hamish B. Wallace ◽  
Jan-Bernd Stukenborg ◽  
...  

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.


Reproduction ◽  
2012 ◽  
Vol 144 (6) ◽  
pp. 737-745 ◽  
Author(s):  
Thaís F G Lucas ◽  
Luciana S Amaral ◽  
Catarina S Porto ◽  
Luis E M Quintas

Novel roles for the interaction of cardiotonic steroids to Na+/K+-ATPase have been established in recent years. The aim of this study was to investigate the intracellular signaling events downstream the action of ouabain on Na+/K+-ATPase in Sertoli cell obtained from immature rats. Treatment of Sertoli cells with ouabain (1 μM) induced a rapid and transient increase in the extracellular signal-regulated kinase (ERK1/2 or MAPK3/1) and phosphatidylinositol 3-kinase (PI3K)/serine–threonine protein kinase (AKT) phosphorylation. Also, ouabain upregulated the expression of cyclin D1 and incorporation of [methyl-3H]thymidine, both of which were dependent on MAPK3/1 but not AKT intracellular cascade, as shown by pretreatment with MEK (MAP2K1/2) inhibitor U0126 and PI3K inhibitor wortmannin respectively. Moreover, the effect of ouabain on these proliferation parameters was completely prevented by phospho-cAMP response element-binding protein (CREB)/CREB-binding protein complex inhibitor KG501 and only partially by nuclear factor κB nuclear translocation inhibitor SN50. Pretreatment with estrogen receptor antagonist ICI 182 780 showed that MAPK3/1 activation by ouabain does not involve this receptor. The Na+/K+-ATPase α1 isoform, but not α4, was detected in Sertoli cells, suggesting that ouabain effects in Sertoli cells are mediated via α1. Taken together, these results show a rapid ouabain action in the Sertoli cells, which in turn can modulate nuclear transcriptional events essential for Sertoli cell proliferation in a critical period of testicular development. Our findings are important to understand the role of ouabain in the testis and its possible implications in male infertility.


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.


2003 ◽  
Vol 178 (3) ◽  
pp. 395-403 ◽  
Author(s):  
SA McCoard ◽  
TH Wise ◽  
DD Lunstra ◽  
JJ Ford

Chinese Meishan (MS) boars have smaller testes due to fewer Sertoli cells compared with White Composite (WC) boars. The objective was to describe Sertoli cell development relative to circulating FSH concentrations in fetal and neonatal MS and WC boars. Testes and blood samples were collected on days 60, 75, 90 and 105 postcoitum (dpc) and 1, 7, 14 and 25 postpartum (dpp). One testis was immunostained for GATA4 or Ki67 antigen to evaluate total and proliferating Sertoli cell numbers respectively. Testicular size was greater (P<0.01) in WC than MS boars at all ages, associated with a greater mass of interstitial tIssue. Tubular mass (P<0.01) was greater in prenatal WC boars, but postnatally increased more rapidly (P<0.001) in MS boars, exceeding WC boars by 25 dpp. Sertoli cell numbers increased with age, was greater (P<0.001) in WC than MS boars during prenatal development but increased rapidly (P<0.01) by 1 dpp in MS and thereafter was similar in both breeds. The proportion of Ki67-positive Sertoli cells was maximal at 90 dpc, declining thereafter, did not differ between breeds through 7 dpp, but was greater (P<0.05) in WC than MS boars at 14 and 25 dpp. Plasma FSH concentrations were greater (P<0.05) in WC than MS boars at 75 dpc. FSH concentrations were elevated at 105 dpc (MS) and 1 dpp (WC) but declined thereafter with advancing postnatal age in both breeds. This study illustrates that late gestation represents the period of maximal Sertoli cell proliferation. Despite asynchronous Sertoli cell population growth between breeds during early postnatal life, differential mature Sertoli cell numbers and testicular size are probably due to differences in duration of the proliferative period after 25 dpp, potentially regulated by Sertoli cell maturation and blood-testis barrier formation. These events were not associated with fetal or early postnatal changes in FSH secretion.


Reproduction ◽  
2007 ◽  
Vol 133 (6) ◽  
pp. 1169-1179 ◽  
Author(s):  
Tu’uhevaha J Kaitu’u-Lino ◽  
Pavel Sluka ◽  
Caroline F H Foo ◽  
Peter G Stanton

Claudin-11 and occludin are protein components in tight junctions (TJs) between Sertoli cells which are important for the maintenance of the blood–testis barrier. Barrier formation occurs during puberty, with evidence suggesting hormonal regulation of both claudin-11 and occludin. This study aimed to investigate the regulation of claudin-11 and occludin mRNA expression by testosterone (T) and FSH and their immunolocalisation at rat Sertoli cell TJsin vitro, and to correlate any steroid regulation with the functional capacity of TJs. Sertoli cells formed functional TJs within 3 days as assessed by transepithelial electrical resistance (TER). Both T and dihydrotestosterone significantly (P< 0.01) increased TER twofold and claudin-11 mRNA two- to threefold within 3 days. FSH partially stimulated TER and claudin-11 mRNA, but estradiol had no effect. T also promoted claudin-11 localisation into extensive intercellular contacts. In contrast to claudin-11, Tand FSH did not change occludin mRNA expression, however, T promoted localisation of occludin at cell contacts in a similar manner to claudin-11. Addition of flutamide to T-stimulated cells caused a twofold decrease in both TER and claudin-11 mRNA expression, and resulted in the loss of both proteins from cell contacts. This effect was reversible following flutamide removal. It is concluded that androgens i) co-regulate claudin-11 mRNA expression and TER, implicating claudin-11 in TJ formation and ii) promote the localisation of claudin-11 and occludin at Sertoli cell contacts. Hence, the ability of androgens to maintain spermatogenesisin vivois partly via their effects on TJ proteins and regulation of the blood–testis barrier.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1565 ◽  
Author(s):  
Linxi Li ◽  
Ying Gao ◽  
Haiqi Chen ◽  
Tito Jesus ◽  
Elizabeth Tang ◽  
...  

In the rat testis, studies have shown that cell polarity, in particular spermatid polarity, to support spermatogenesis is conferred by the coordinated efforts of the Par-, Crumbs-, and Scribble-based polarity complexes in the seminiferous epithelium. Furthermore, planar cell polarity (PCP) is conferred by PCP proteins such as Van Gogh-like 2 (Vangl2) in the testis. On the other hand, cell junctions at the Sertoli cell–spermatid (steps 8–19) interface are exclusively supported by adhesion protein complexes (for example, α6β1-integrin-laminin-α3,β3,γ3 and nectin-3-afadin) at the actin-rich apical ectoplasmic specialization (ES) since the apical ES is the only anchoring device in step 8–19 spermatids. For cell junctions at the Sertoli cell–cell interface, they are supported by adhesion complexes at the actin-based basal ES (for example, N-cadherin-β-catenin and nectin-2-afadin), tight junction (occludin-ZO-1 and claudin 11-ZO-1), and gap junction (connexin 43-plakophilin-2) and also intermediate filament-based desmosome (for example, desmoglein-2-desmocollin-2). In short, the testis-specific actin-rich anchoring device known as ES is crucial to support spermatid and Sertoli cell adhesion. Accumulating evidence has shown that the Par-, Crumbs-, and Scribble-based polarity complexes and the PCP Vangl2 are working in concert with actin- or microtubule-based cytoskeletons (or both) and these polarity (or PCP) protein complexes exert their effects through changes in the organization of the cytoskeletal elements across the seminiferous epithelium of adult rat testes. As such, there is an intimate relationship between cell polarity, cell adhesion, and cytoskeletal function in the testis. Herein, we critically evaluate these recent findings based on studies on different animal models. We also suggest some crucial future studies to be performed.


2002 ◽  
Vol 5 (6) ◽  
pp. 544-550 ◽  
Author(s):  
Ricardo Drut ◽  
Rosa Mónica Drut

Testicular microlithiasis (TM) is being recognized with increasing frequency because of the extensive use of ultrasound. TM has been linked to several pathological conditions of the testis, mainly with an increased risk for developing germ cell tumors. The pathogenesis of the microcalcospherites is unknown. We report a detailed morphologic and immunohistochemical analysis of 11 patients (age: 3 to 15 years) with TM. The microliths were related neither to the age of the children nor to the developmental stage of the testis. The microcalcospherites were PAS positive or collagen IV positive or surrounded by a collagen IV–positive band, extratubular structures consistently associated with double-layered annular tubules. Immature, smaller Sertoli cells commonly lined the inner layer of the annular tubules. Some microcalcospherites showed an interposed thin band of connective tissue cells between the concretion and the tubular basement membrane. The annular tubules seemed to result from progressive wrapping of the growing tubules around the concretions. Our findings favor the interpretation that the microliths are located outside the tubules and have been present there since very early stages of testicular development. The association of the calcospherites with Sertoli cells and annular tubules formation, like that of gonadal stromal tumor with annular tubules of the ovary and large cell–calcifying Sertoli cell tumor of the testis, favors the hypothesis that microliths may result from multifocal Sertoli cell dysfunction. Since both tumors are related to the Peutz-Jeghers syndrome, it is proposed that TM may result from the same genetic abnormalities. It is unclear how this may be related to the development of germ cell tumors. However, the presence of calcospherites in gonadoblastoma may indicate a combined Sertoli cell and germ cell derangement in the genesis of TM.


Sign in / Sign up

Export Citation Format

Share Document