scholarly journals Differential effects of c-Src and c-Yes on the endocytic vesicle-mediated trafficking events at the Sertoli cell blood-testis barrier: an in vitro study

2014 ◽  
Vol 307 (7) ◽  
pp. E553-E562 ◽  
Author(s):  
Xiang Xiao ◽  
Dolores D. Mruk ◽  
Elissa W. P. Wong ◽  
Will M. Lee ◽  
Daishu Han ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Protein Trafficking ◽  
In Vitro Study ◽  
Underlying Mechanism ◽  
Endocytic Vesicle ◽  
Immunological Barrier ◽  
Blood Testis Barrier

The blood-testis barrier (BTB) is one of the tightest blood-tissue barriers in the mammalian body. However, it undergoes cyclic restructuring during the epithelial cycle of spermatogenesis in which the “old” BTB located above the preleptotene spermatocytes being transported across the immunological barrier is “disassembled,” whereas the “new” BTB found behind these germ cells is rapidly “reassembled,” i.e., mediated by endocytic vesicle-mediated protein trafficking events. Thus, the immunological barrier is maintained when preleptotene spermatocytes connected in clones via intercellular bridges are transported across the BTB. Yet the underlying mechanism(s) in particular the involving regulatory molecules that coordinate these events remains unknown. We hypothesized that c-Src and c-Yes might work in contrasting roles in endocytic vesicle-mediated trafficking, serving as molecular switches, to effectively disassemble and reassemble the old and the new BTB, respectively, to facilitate preleptotene spermatocyte transport across the BTB. Following siRNA-mediated specific knockdown of c-Src or c-Yes in Sertoli cells, we utilized biochemical assays to assess the changes in protein endocytosis, recycling, degradation and phagocytosis. c-Yes was found to promote endocytosed integral membrane BTB proteins to the pathway of transcytosis and recycling so that internalized proteins could be effectively used to assemble new BTB from the disassembling old BTB, whereas c-Src promotes endocytosed Sertoli cell BTB proteins to endosome-mediated protein degradation for the degeneration of the old BTB. By using fluorescence beads mimicking apoptotic germ cells, Sertoli cells were found to engulf beads via c-Src-mediated phagocytosis. A hypothetical model that serves as the framework for future investigation is thus proposed.

Germ cell-Sertoli cell interactions

1990 ◽  
Vol 2 (3) ◽  
pp. 225 ◽  
Author(s):  
Kretser DM de
Keyword(s):  
Germ Cell ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Cell Interactions ◽  
Cell Contact ◽  
Paracrine Factors ◽  
Cytological Changes ◽  
Cyclic Changes ◽  
Blood Testis Barrier

The interactions between the Sertoli cells and germ cells are progressively becoming an important part of testicular physiology. This paper explores the cytological basis for these interactions, detailing the cyclic changes in the Sertoli cells in concert with the stages of the seminiferous cycle and the nature of the blood-testis barrier. These cytological changes are correlated with a number of variations in the function of Sertoli cells. The mechanisms by which germ cells and Sertoli cells interact are explored and can be divided into those using cell-to-cell contact and others utilizing paracrine factors.

scholarly journals rpS6 Regulates Blood-Testis Barrier Dynamics Through Arp3-Mediated Actin Microfilament Organization in Rat Sertoli Cells. An In Vitro Study

Endocrinology ◽  
2015 ◽  
Vol 156 (5) ◽  
pp. 1900-1913 ◽  
Author(s):  
Ka-Wai Mok ◽  
Haiqi Chen ◽  
Will M. Lee ◽  
C. Yan Cheng
Keyword(s):  
Sertoli Cells ◽  
Protein Complexes ◽  
Mammalian Target Of Rapamycin ◽  
Attachment Site ◽  
In Vitro Study ◽  
Site Directed Mutagenesis ◽  
Actin Microfilaments ◽  
Blood Testis Barrier

In the seminiferous epithelium of rat testes, preleptotene spermatocytes residing in the basal compartment are transported across the blood-testis barrier (BTB) to enter the adluminal compartment at stage VIII of the epithelial cycle. This process involves redistribution of tight junction (TJ) proteins via reorganization of actin cytoskeleton in Sertoli cells that serves as attachment site for adhesion protein complexes. Ribosomal protein S6 (rpS6), a downstream molecule of mTORC1 (mammalian target of rapamycin complex 1), participates in this process via a yet-to-be defined mechanism. Here, we constructed an rpS6 quadruple phosphomimetic mutant by converting Ser residues at 235, 236, 240, and 244 to Glu via site-directed mutagenesis, making this mutant constitutively active. When this rpS6 mutant was overexpressed in Sertoli cells cultured in vitro with an established TJ barrier mimicking the BTB in vivo, it perturbed the TJ permeability by down-regulating and redistributing TJ proteins at the cell-cell interface. These changes are mediated by a reorganization of actin microfilaments, which was triggered by a redistribution of activated actin-related protein 3 (Arp3) as well as changes in Arp3-neuronal Wiskott-Aldrich Syndrome protein (N-WASP) interaction. This in turn induced reorganization of actin microfilaments, converting them from a “bundled” to an “unbundled/branched” configuration, concomitant with a reduced actin bundling activity, thereby destabilizing the TJ-barrier function. These changes were mediated by Akt (transforming oncogene of v-akt), because an Akt knockdown by RNA interference was able to mimic the phenotypes of rpS6 mutant overexpression at the Sertoli cell BTB. In summary, this study illustrates a mechanism by which mTORC1 signal complex regulates BTB function through rpS6 downstream by modulating actin organization via the Arp2/3 complex, which may be applicable to other tissue barriers.

scholarly journals EB1 Regulates Tubulin and Actin Cytoskeletal Networks at the Sertoli Cell Blood-Testis Barrier in Male Rats: An In Vitro Study

Endocrinology ◽  
2014 ◽  
Vol 156 (2) ◽  
pp. 680-693 ◽  
Author(s):  
Elizabeth I. Tang ◽  
Ka-Wai Mok ◽  
Will M. Lee ◽  
C. Yan Cheng
Keyword(s):  
Sertoli Cell ◽  
In Vitro Study ◽  
Vitro Study ◽  
Male Rats ◽  
Cytoskeletal Networks ◽  
Blood Testis Barrier

scholarly journals Claudin-11 expression and localisation is regulated by androgens in rat Sertoli cells in vitro

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
Keyword(s):  
Mrna Expression ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Hormonal Regulation ◽  
Cell Contacts ◽  
Barrier Formation ◽  
Protein Components ◽  
Blood Testis Barrier

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.

scholarly journals Two distinct Sertoli cell states are regulated via germ cell crosstalk†

2021 ◽  
Author(s):  
Rachel L Gewiss ◽  
Nathan C Law ◽  
Aileen R Helsel ◽  
Eric A Shelden ◽  
Michael D Griswold
Keyword(s):  
Germ Cell ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Seminiferous Tubule ◽  
Seminiferous Epithelium ◽  
Critical Component ◽  
Cell Transcriptome ◽  
Cell Crosstalk ◽  
Blood Testis Barrier

Abstract Sertoli cells are a critical component of the testis environment for their role in maintaining seminiferous tubule structure, establishing the blood-testis barrier, and nourishing maturing germ cells in a specialized niche. This study sought to uncover how Sertoli cells are regulated in the testis environment via germ cell crosstalk in the mouse. We found two major clusters of Sertoli cells as defined by their transcriptomes in Stages VII–VIII of the seminiferous epithelium and a cluster for all other stages. Additionally, we examined transcriptomes of germ cell-deficient testes and found that these existed in a state independent of either of the germ cell-sufficient clusters. Altogether, we highlight two main transcriptional states of Sertoli cells in an unperturbed testis environment, and a germ cell-deficient environment does not allow normal Sertoli cell transcriptome cycling and results in a state unique from either of those seen in Sertoli cells from a germ cell-sufficient environment.

scholarly journals UXT in Sertoli cells is required for blood–testis barrier integrity†

2020 ◽  
Vol 103 (4) ◽  
pp. 880-891
Author(s):  
Phillip A Thomas ◽  
Eric D Schafler ◽  
Sophie E Ruff ◽  
Maud Voisin ◽  
Susan Ha ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Structural Integrity ◽  
Cell Function ◽  
Somatic Tissue ◽  
Seminiferous Tubules ◽  
Testis Size ◽  
Conditional Deletion ◽  
Blood Testis Barrier

Abstract Spermatogenesis is a complex process that establishes male fertility and involves proper communication between the germline (spermatozoa) and the somatic tissue (Sertoli cells). Many factors that are important for spermatozoa production are also required for Sertoli cell function. Recently, we showed that the transcriptional cofactor ubiquitously expressed transcript (UXT) encodes a protein that is essential in germ cells for spermatogenesis and fertility. However, the role of UXT within Sertoli cells and how it affects Sertoli cell function was still unclear. Here we describe a novel role for UXT in the Sertoli cell’s ability to support spermatogenesis. We find that the conditional deletion of Uxt in Sertoli cells results in smaller testis size and weight, which coincided with a loss of germ cells in a subset of seminiferous tubules. In addition, the deletion of Uxt has no impact on Sertoli cell abundance or maturity, as they express markers of mature Sertoli cells. Gene expression analysis reveals that the deletion of Uxt in Sertoli cells reduces the transcription of genes involved in the tight junctions of the blood–testis barrier (BTB). Furthermore, tracer experiments and electron microscopy reveal that the BTB is permeable in UXT KO animals. These findings broaden our understanding of UXT’s role in Sertoli cells and its contribution to the structural integrity of the BTB.

scholarly journals Perfluorooctanesulfonate (PFOS) Perturbs Male Rat Sertoli Cell Blood-Testis Barrier Function by Affecting F-Actin Organization via p-FAK-Tyr407: An in Vitro Study

Endocrinology ◽  
2014 ◽  
Vol 155 (1) ◽  
pp. 249-262 ◽  
Author(s):  
Hin-Ting Wan ◽  
Dolores D. Mruk ◽  
Chris K. C. Wong ◽  
C. Yan Cheng
Keyword(s):  
Tight Junction ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Connexin 43 ◽  
Male Rat ◽  
Environmental Toxicants ◽  
Adhesion Proteins ◽  
Actin Organization ◽  
Blood Testis Barrier

Environmental toxicants such as perfluorooctanesulfonate (PFOS) have been implicated in male reproductive dysfunction, including reduced sperm count and semen quality, in humans. However, the underlying mechanism(s) remains unknown. Herein PFOS at 10–20 μM (∼5–10 μg/mL) was found to be more potent than bisphenol A (100 μM) in perturbing the blood-testis barrier (BTB) function by disrupting the Sertoli cell tight junction-permeability barrier without detectable cytotoxicity. We also delineated the underlying molecular mechanism by which PFOS perturbed Sertoli cell BTB function using an in vitro model that mimics the BTB in vivo. First, PFOS perturbed F-actin organization in Sertoli cells, causing truncation of actin filaments at the BTB. Thus, the actin-based cytoskeleton was no longer capable of supporting the distribution and/or localization of actin-regulatory and adhesion proteins at the cell-cell interface necessary to maintain BTB integrity. Second, PFOS was found to perturb inter-Sertoli cell gap junction (GJ) communication based on a dye-transfer assay by down-regulating the expression of connexin-43, a GJ integral membrane protein. Third, phosphorylated focal adhesion kinase (FAK)-Tyr407 was found to protect the BTB from the destructive effects of PFOS as shown in a study via an overexpression of an FAK Y407E phosphomimetic mutant. Also, transfection of Sertoli cells with an FAK-specific microRNA, miR-135b, to knock down the expression of phosphorylated FAK-Tyr407 was found to worsen PFOS-mediated Sertoli cell tight junction disruption. In summary, PFOS-induced BTB disruption is mediated by down-regulating phosphorylated FAK-Tyr407 and connexin-43, which in turn perturbed F-actin organization and GJ-based intercellular communication, leading to mislocalization of actin-regulatory and adhesion proteins at the BTB.

002.Sertoli cell terminal differentiation: doing a 'U' turn on a one way street

2005 ◽  
Vol 17 (9) ◽  
pp. 62
Author(s):  
S. J. Meachem
Keyword(s):  
Cell Proliferation ◽  
Tight Junction ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Proliferative Activity ◽  
Terminal Differentiation ◽  
Tight Junction Proteins ◽  
Junction Proteins ◽  
Blood Testis Barrier

The concept of terminal differentiation of Sertoli cells has been challenged and this new information has important implications for male fertility. The mammalian Sertoli cell has two distinct functions: (i) formation of the seminiferous cords and (ii) provision of nutritional and structural support to the developing germ cells. For these to occur successfully, Sertoli cells must undergo numerous maturational changes between foetal and adult life, the main switches occur around the onset of puberty, coincident with the rise in serum gonadotrophins. These switches include the loss of proliferative activity and the formation of the blood testis barrier. Follicle stimulating hormone (FSH) plays a key role in supporting Sertoli cell proliferation in early postnatal life and thus is critical in establishing sperm output in adulthood. After puberty, the size of the Sertoli cell population is considered to be stable and unmodifiable by hormones. This accepted view has been contested as data shows that the size of the adult Sertoli cell population is modifiable by hormone suppression, and that Sertoli cells can regain proliferative activity when stimulated by FSH in the Djungarian hamster1. The molecular mechanism(s) by which Sertoli cells re-enter proliferation are not known in this model however a study demonstrated that helix-loop-inhibitor of differentiation proteins can induce terminally differentiated Sertoli cells to re-enter the cell cycle and proliferate2. Thyroid hormone and testosterone may be involved in the cessation of Sertoli cell proliferation. Gonadotrophin suppression in the adult Djungarian hamster also results in the disruption of the blood testis barrier and spatial organisation of the inter Sertoli cell tight junction proteins and as a consequence the loss of all germ cells that reside inside the blood testis barrier. FSH restores the organisation of these tight junction proteins, which is associated with the appearance of more mature germ cells. It is expected that the integrity of the blood testis barrier is also re-established. It is suggested that this demonstrated plasticity of the adult Sertoli cell may be relevant in clinical settings, particularly to some types of infertility and testicular malignancies where Sertoli cells have failed to undergo these important maturational switches. (1)Chaudhary et al. (2005) Biol. Reprod. 72, 1205. (2)Meachem et al. (2005) Biol. Reprod. 72, 1187.

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