scholarly journals 14-3-3 Protein Regulates Cell Adhesion in the Seminiferous Epithelium of Rat Testes

Endocrinology ◽  
2009 ◽  
Vol 150 (10) ◽  
pp. 4713-4723 ◽  
Author(s):  
Elissa W. P. Wong ◽  
Shengyi Sun ◽  
Michelle W. M. Li ◽  
Will M. Lee ◽  
C. Yan Cheng
Keyword(s):  
Cell Adhesion ◽  
Cell Polarity ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Mammalian Cells ◽  
Critical Role ◽  
Seminiferous Epithelium ◽  
General Mechanism ◽  
Permeability Barrier ◽  
Polarity Proteins

Abstract Polarity proteins have been implicated in regulating and maintaining tight junction (TJ) and cell polarity in epithelia. Here we report 14-3-3θ, the homolog of Caenorhabditis elegans Par5 in mammalian cells, which is known to confer cell polarity at TJ, is found at the apical ectoplasmic specialization (ES), a testis-specific adherens junction type restricted to the Sertoli cell-elongating spermatid interface, in which TJ is absent. 14-3-3θ was shown to play a critical role in conferring cell adhesion at the apical ES. A loss of 14-3-3θ expression at the apical ES was detected in the seminiferous epithelium before spermiation. Involvement of 14-3-3θ in Sertoli cell adhesion was confirmed by its knockdown by RNA interference in Sertoli cells cultured in vitro with established TJ permeability barrier that mimicked the blood-testis barrier (BTB) in vivo. Mislocalization of N-cadherin and zonula occludens-1, but not α- and β-catenins, was observed after 14-3-3θ knockdown in Sertoli cells, moving from the cell-cell interface to cytosol, indicating a disruption of cell adhesion. Studies by endocytosis assay illustrated that this loss of cell adhesion was mediated by an increase in the kinetics of endocytosis of N-cadherin and junctional adhesion molecule-A at the BTB, which may represent a general mechanism by which polarity proteins regulate cell adhesion. In summary, the testis is using 14-3-3θ to regulate cell adhesion at the apical ES to facilitate spermiation and at the BTB to facilitate the transit of preleptotene spermatocytes at stages VIII–IX of the epithelial cycle. 14-3-3θ may act as a molecular switch that coordinates these two cellular events in the seminiferous epithelium during spermatogenesis.

scholarly journals c-Yes regulates cell adhesion at the apical ectoplasmic specialization-blood-testis barrier axis via its effects on protein recruitment and distribution

2013 ◽  
Vol 304 (2) ◽  
pp. E145-E159 ◽  
Author(s):  
Xiang Xiao ◽  
Dolores D. Mruk ◽  
C. Yan Cheng
Keyword(s):  
Cell Adhesion ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Early Stage ◽  
Seminiferous Epithelium ◽  
Permeability Barrier ◽  
Cell Interface ◽  
Ectoplasmic Specialization ◽  
Cell Cell ◽  
Blood Testis Barrier

During spermatogenesis, extensive restructuring takes place at the cell-cell interface since developing germ cells migrate progressively from the basal to the adluminal compartment of the seminiferous epithelium. Since germ cells per se are not motile cells, their movement relies almost exclusively on the Sertoli cell. Nonetheless, extensive exchanges in signaling take place between these cells in the seminiferous epithelium. c-Yes, a nonreceptor protein tyrosine kinase belonging to the Src family kinases (SFKs) and a crucial signaling protein, was recently shown to be upregulated at the Sertoli cell-cell interface at the blood-testis barrier (BTB) at stages VIII–IX of the seminiferous epithelial cycle of spermatogenesis. It was also highly expressed at the Sertoli cell-spermatid interface known as apical ectoplasmic specialization (apical ES) at stage V to early stage VIII of the epithelial cycle during spermiogenesis. Herein, it was shown that the knockdown of c-Yes by RNAi in vitro and in vivo affected both Sertoli cell adhesion at the BTB and spermatid adhesion at the apical ES, causing a disruption of the Sertoli cell tight junction-permeability barrier function, germ cell loss from the seminiferous epithelium, and also a loss of spermatid polarity. These effects were shown to be mediated by changes in distribution and/or localization of adhesion proteins at the BTB (e.g., occludin, N-cadherin) and at the apical ES (e.g., nectin-3) and possibly the result of changes in the underlying actin filaments at the BTB and the apical ES. These findings implicate that c-Yes is a likely target of male contraceptive research.

scholarly journals Cell polarity, cell adhesion, and spermatogenesis: role of cytoskeletons

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1565 ◽  
Author(s):  
Linxi Li ◽  
Ying Gao ◽  
Haiqi Chen ◽  
Tito Jesus ◽  
Elizabeth Tang ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Polarity ◽  
Sertoli Cell ◽  
Connexin 43 ◽  
Planar Cell Polarity ◽  
Protein Complexes ◽  
Seminiferous Epithelium ◽  
Cell Junctions ◽  
Adhesion Protein ◽  
Adult Rat

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.

scholarly journals Ezrin is an Actin Binding Protein That Regulates Sertoli Cell and Spermatid Adhesion During Spermatogenesis

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3981-3995 ◽  
Author(s):  
N. Ece Gungor-Ordueri ◽  
Elizabeth I. Tang ◽  
Ciler Celik-Ozenci ◽  
C. Yan Cheng
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Adherens Junction ◽  
Actin Binding ◽  
Permeability Barrier ◽  
Tight Junction Permeability ◽  
Residual Bodies ◽  
Cell Interface

Abstract During spermatogenesis, the transport of spermatids and the release of sperms at spermiation and the remodeling of the blood-testis barrier (BTB) in the seminiferous epithelium of rat testes require rapid reorganization of the actin-based cytoskeleton. However, the mechanism(s) and the regulatory molecule(s) remain unexplored. Herein we report findings that unfold the functional significance of ezrin in the organization of the testis-specific adherens junction at the spermatid-Sertoli cell interface called apical ectoplasmic specialization (ES) in the adluminal compartment and the Sertoli cell-cell interface known as basal ES at the BTB. Ezrin is expressed at the basal ES/BTB in all stages, except from late VIII to IX, of the epithelial cycle. Its knockdown by RNA interference (RNAi) in vitro perturbs the Sertoli cell tight junction-permeability barrier via a disruption of the actin microfilaments in Sertoli cells, which in turn impeded basal ES protein (eg, N-cadherin) distribution, perturbing the BTB function. These findings were confirmed by a knockdown study in vivo. However, the expression of ezrin at the apical ES is restricted to stage VIII of the cycle and limited only between step 19 spermatids and Sertoli cells. A knockdown of ezrin in vivo by RNAi was found to impede spermatid transport, causing defects in spermiation in which spermatids were embedded deep inside the epithelium, and associated with a loss of spermatid polarity. Also, ezrin was associated with residual bodies and phagosomes, and its knockdown by RNAi in the testis also impeded the transport of residual bodies/phagosomes from the apical to the basal compartment. In summary, ezrin is involved in regulating actin microfilament organization at the ES in rat testes.

148. HORMONALLY REGULATED miRNAS TARGET THE TUBULOBULBAR COMPLEX IN THE TESTIS

2010 ◽  
Vol 22 (9) ◽  
pp. 66
Author(s):  
P. K. Nicholls ◽  
P. G. Stanton ◽  
K. L. Walton ◽  
R. I. McLachlan ◽  
L. O'Donnell ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Hormonal Regulation ◽  
Focal Adhesions ◽  
Intercellular Junctions ◽  
Protein Translation ◽  
Seminiferous Epithelium ◽  
Seminiferous Tubules ◽  
Micro Rnas

Spermatogenesis is absolutely dependent on follicle stimulating hormone (FSH) and androgens; acute suppression of these hormones inhibits germ cell development and thus sperm production. The removal of intercellular junctions and release of spermatids by the Sertoli cell, a process known as spermiation, is particularly sensitive to acute hormone suppression(1). To define the molecular mechanisms that mediate FSH and androgen effects in the testis, we investigated the expression and hormonal regulation of micro-RNAs (miRNA), small non-coding RNAs that regulate protein translation and modify cellular responses. By array analysis, we identified 23 miRNAs that were upregulated >2-fold in stage VIII seminiferous tubules following hormone suppression, and in vitro in primary Sertoli cells. We subsequently validated the expression and hormonal regulation of several miRNAs, including miR-23b, -30d and -690 by quantitative PCR in primary Sertoli cells. Bioinformatic analysis of potential targets of hormonally-suppressed miRNAs identified genes associated with Focal adhesions (54 genes, P = –ln(17.97)) and the Regulation of the actin cytoskeleton (52 genes, P = –ln(10.16)), processes known to be intimately associated with adhesion of spermatids to Sertoli cells(2, 3). Furthermore, this analysis identified numerous components of the testicular tubulobulbar complex (TBC) as being targets of hormonally sensitive miRNAs. The TBC is a podosome-like structure between Sertoli and adjacent spermatids in the testis, which internalises intact inter-cellular junctions by endocytotic mechanisms prior to spermiation(4). We then demonstrate the hormonal regulation of predicted miRNA target proteins, and validate novel inhibitory miRNA interactions with Pten, nWASP, Eps15 and Picalm by luciferase knockdown in vitro. We hypothesise that hormonally suppressed miRNAs inhibit TBC function, and subsequently, endocytosis of intercellular junctions. In conclusion, we have demonstrated that hormonal suppression in the testis stimulates the expression of a subset of Sertoli cell miRNAs that are likely regulators of cell adhesion protein networks involved in spermiation. (1) Saito K, O’Donnell L, McLachlan RI, Robertson DM 2000 Spermiation failure is a major contributor to early spermatogenic suppression caused by hormone withdrawal in adult rats. Endocrinology 141: 2779–2.(2) O’Donnell L, Stanton PG, Bartles JR, Robertson DM 2000 Sertoli cell ectoplasmic specializations in the seminiferous epithelium of the testosterone-suppressed adult rat. Biol Reprod 63: 99–108.(3) Beardsley A, Robertson DM, O’Donnell L 2006 A complex containing alpha6beta1-integrin and phosphorylated focal adhesion kinase between Sertoli cells and elongated spermatids during spermatid release from the seminiferous epithelium. J Endocrinol 190(3): 759–70.(4) Young JS, Guttman JA, Vaid KS, Vogl AW 2009 Tubulobulbar complexes are intercellular podosome-like structures that internalize intact intercellular junctions during epithelial remodeling events in the rat testis. Biol Reprod 80: 162–74.

scholarly journals Cyclic Expression of Endothelin-converting Enzyme-1 Mediates the Functional Regulation of Seminiferous Tubule Contraction

1999 ◽  
Vol 145 (5) ◽  
pp. 1027-1038 ◽  
Author(s):  
Antonella Tripiciano ◽  
Carmelina Peluso ◽  
Anna Rita Morena ◽  
Fioretta Palombi ◽  
Mario Stefanini ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Seminiferous Tubule ◽  
Seminiferous Epithelium ◽  
Seminiferous Tubules ◽  
Converting Enzyme ◽  
Myoid Cells ◽  
Endothelin 1 ◽  
Endothelin Converting Enzyme ◽  
Cyclic Expression

The potent smooth muscle agonist endothelin-1 (ET-1) is involved in the local control of seminiferous tubule contractility, which results in the forward propulsion of tubular fluid and spermatozoa, through its action on peritubular myoid cells. ET-1, known to be produced in the seminiferous epithelium by Sertoli cells, is derived from the inactive intermediate big endothelin-1 (big ET-1) through a specific cleavage operated by the endothelin-converting enzyme (ECE), a membrane-bound metalloprotease with ectoenzymatic activity. The data presented suggest that the timing of seminiferous tubule contractility is controlled locally by the cyclic interplay between different cell types. We have studied the expression of ECE by Sertoli cells and used myoid cell cultures and seminiferous tubule explants to monitor the biological activity of the enzymatic reaction product. Northern blot analysis showed that ECE-1 (and not ECE-2) is specifically expressed in Sertoli cells; competitive enzyme immunoassay of ET production showed that Sertoli cell monolayers are capable of cleaving big ET-1, an activity inhibited by the ECE inhibitor phosphoramidon. Microfluorimetric analysis of intracellular calcium mobilization in single cells showed that myoid cells do not respond to big endothelin, nor to Sertoli cell plain medium, but to the medium conditioned by Sertoli cells in the presence of big ET-1, resulting in cell contraction and desensitization to further ET-1 stimulation; in situ hybridization analysis shows regional differences in ECE expression, suggesting that pulsatile production of endothelin by Sertoli cells (at specific “stages” of the seminiferous epithelium) may regulate the cyclicity of tubular contraction; when viewed in a scanning electron microscope, segments of seminiferous tubules containing the specific stages characterized by high expression of ECE were observed to contract in response to big ET-1, whereas stages with low ECE expression remained virtually unaffected. These data indicate that endothelin-mediated spatiotemporal control of rhythmic tubular contractility might be operated by Sertoli cells through the cyclic expression of ECE-1, which is, in turn, dependent upon the timing of spermatogenesis.

scholarly journals Rictor Regulates Spermatogenesis by Controlling Sertoli Cell Cytoskeletal Organization and Cell Polarity in the Mouse Testis

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4244-4256 ◽  
Author(s):  
Heling Dong ◽  
Zhenguo Chen ◽  
Caixia Wang ◽  
Zhi Xiong ◽  
Wanlu Zhao ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Cell Function ◽  
Regulatory Protein ◽  
Small Gtpase ◽  
Mutant Mice ◽  
Actin Dynamics ◽  
Testicular Development ◽  
Developmental Defects

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.

Wnt5a Regulates Junctional Function of Sertoli cells Through PCP-Mediated Effects on mTORC1 and mTORC2

Endocrinology ◽  
2021 ◽  
Author(s):  
Yan Fu ◽  
Yuexin Wei ◽  
Yu Zhou ◽  
Huan Wu ◽  
Yifan Hong ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Wnt Signaling Pathway ◽  
Seminiferous Epithelium ◽  
Cell Junctions ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Cell Junction ◽  
Specific Expression

Abstract The blood-testis barrier (BTB) and apical ectoplasmic specialization (ES), which are synchronized through the crosstalk of Sertoli cells and Sertoli-germ cells, are required for spermatogenesis and sperm release. Here, we show that Wnt5a, a noncanonical Wnt signaling pathway ligand, is predominately expressed in both the BTB and apical ES and has a specific expression pattern during the seminiferous epithelium cycle. We employed siRNA to knockdown Wnt5a expression in testis and Sertoli cells and then identified elongated spermatids that lost their polarity, and were embedded in the seminiferous epithelium. Moreover, phagosomes were found near the tubule lumen. These defects were due to BTB and apical ES disruption. We also verified that the expression level and/or location of BTB-associated proteins, actin-binding proteins (ABPs) and F-actin was changed after Wnt5a knockdown in vivo and in vitro. Additionally, we demonstrated that Wnt5a regulated actin dynamics through Ror2-mediated mTORC1 and mTORC2. This study clarified the molecular mechanism of Wnt5a in Sertoli cell junctions through the planar cell polarity (PCP) signaling pathway. Our findings could provide an experimental basis for the clinical diagnosis and treatment of male infertility caused by Sertoli cell junction impairment.

scholarly journals Influence of scrotal bipartition on spermatogenesis yield and sertoli cell efficiency in sheep

2016 ◽  
Vol 36 (4) ◽  
pp. 258-262 ◽  
Author(s):  
Ramon T.G.A. Rodrigues ◽  
José R.S. Santos ◽  
Lilianne M.S. Azerêdo ◽  
Ediane F. Rocha ◽  
Maria A.M. Carvalho ◽  
...  
Keyword(s):  
Sertoli Cell ◽  
Analysis Of Variance ◽  
Sertoli Cells ◽  
Statistical Difference ◽  
Seminiferous Epithelium ◽  
Mean Values ◽  
Cell Efficiency ◽  
Biometric Parameters ◽  
The Mean ◽  
Reproductive Indices

Abstract With the objective to assess the effect of scrotal bipartition on spermatogenesis in sheep, the testes were used from 12 crossbred rams of sheep farms in the municipality of Patos, Paraíba, Brazil, distributed into two groups: GI with six rams with scrotal bipartition, and GII with six rams without scrotal bipartition. The testicular biometry was measured and the testes were collected, fixed in Bouin and fragments were processed to obtain histological slides. The spermatogenesis yield and the Sertoli cell efficiency was estimated by counting the cells of the spermatogenetic line at stage one of the seminiferous epithelium cycle and the Sertoli cells. The results were submitted to analysis of variance with the ASSISTAT v.7.6 program and the mean values were compared by the Student-Newman-Keuls test (SNK) at 5% significance. The testicular biometric parameters did not show statistical difference (p>0.05) between the groups. The meiotic, spermatogenetic and Sertoli cell efficiency were higher in bipartitioned rams (p<0.05), while the mitotic yield did not differ (p>0.05) between GI and GII. The results indicated that there is superiority in the spermatogenetic parameters of bi-partitioned rams, suggesting that these sheep present, as reported in goats, indication of better reproductive indices.

scholarly journals Regulation of the blood-testis barrier by coxsackievirus and adenovirus receptor

2012 ◽  
Vol 303 (8) ◽  
pp. C843-C853 ◽  
Author(s):  
Linlin Su ◽  
Dolores D. Mruk ◽  
C. Yan Cheng
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Regulatory Protein ◽  
Integral Membrane Protein ◽  
Permeability Barrier ◽  
Structural Protein ◽  
Coxsackievirus And Adenovirus Receptor ◽  
Adenovirus Receptor ◽  
Blood Testis Barrier

The blood-testis barrier (BTB) divides the seminiferous epithelium into the basal and the adluminal compartment. It restricts paracellular diffusion of molecules between Sertoli cells, confers cell polarity, and creates a unique microenvironment in the adluminal compartment for spermatid development. However, it undergoes restructuring during the epithelial cycle so that preleptotene spermatocytes differentiated from type B spermatogonia residing in the basal compartment can traverse the BTB at stage VIII of the cycle, while the immunological barrier is maintained. Herein, coxsackievirus and adenovirus receptor (CAR), a tight junction (TJ) integral membrane protein in the testis and multiple epithelia and endothelia, was found to act as a regulatory protein at the BTB, besides serving as a structural adhesion protein. RNAi-mediated knockdown of CAR in a Sertoli cell epithelium with an established TJ-permeability barrier that mimicked the BTB in vivo resulted in a disruption of the TJ barrier and an increase in endocytosis of the TJ-protein occludin. Furthermore, such an enhancement in occludin endocytosis was accompanied by a downregulation of Thr-phosphorylation in occludin and an increase in the association of endocytosed occludin with early endosome antigen-1. These findings were confirmed by overexpressing CAR in Sertoli cells, which was found to “tighten” the Sertoli cell TJ barrier, promoting BTB function. These findings support the emerging concept that CAR is not only a structural protein, it is involved in conferring the phosphorylation status of other adhesion proteins at the BTB (e.g., occludin) possibly mediated via its structural interactions with nonreceptor protein kinases, thereby modulating endocytic vesicle-mediated protein trafficking.

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