Dolichol and N-linked oligosaccharide synthesis in the rat testis: interaction between Sertoli and spermatogenic cells, evidence for paracrine effects

1992 ◽  
Vol 70 (6) ◽  
pp. 496-503 ◽  
Author(s):  
Kathleen Creed Page ◽  
Paul B. Mason ◽  
Lynn Lindstrom ◽  
James S. Swan ◽  
Sally E. Nyquist

The relative contribution of the Sertoli cell and the pachytene spermatocyte to dolichol and N-linked oligosaccharide biosynthesis within the seminiferous tubule was investigated. Evidence is presented to show that the interaction between these two cell types affects dolichol and N-linked oligosaccharide biosynthesis. Analysis of the dolichol content of Sertoli cultures confirms earlier data suggesting that the Sertoli cell constitutes the major pool of dolichols within the seminiferous tubule. [14C]Acetate incorporation studies suggest that the Sertoli cell in culture synthesizes dolichol much more rapidly than does the isolated pachytene spermatocyte. This information, in addition to previous data in the literature, infers an interactive effect whereby the presence of the spermatogenic cell in the tubule stimulates dolichol synthesis in the Sertoli cell. The absence of normal Sertoli-spermatocyte interactions in in vitro incubations may also limit dolichol synthesis in the pachytene spermatocyte. The distribution of dolichol kinase between the Sertoli and the pachytene spermatocyte was also examined. The concentration of this enzyme in the Sertoli cell suggests the presence of an active salvage pathway within that cell. The correlation between the appearance of the pachytene spermatocyte and the previously described peak of dolichol kinase activity in the seminiferous tubules of the prepubertal animal implies cell–cell interactions. Radiolabelling studies of N-linked oligosaccharides were conducted using [3H]mannose and concanavalin A affinity chromatography to identify multiantennary, biantennary, and high-mannose oligosaccharide pools. An in vitro bicameral coculture system was used to demonstrate that pachytene spermatocytes stimulate incorporation of [3H]mannose into Sertoli cell oligosaccharides. The presence of spermatocytes also induced a shift of label from the multiantennary oligosaccharide pool to the high-mannose pool in the Sertoli cell. Reciprocal experiments, in which the pachytene spermatocyte oligosaccharide pools were observed, showed no significant changes. These studies show a clear pachytene spermatocyte derived paracrine effect on Sertoli cell glycosylation.Key words: glycoprotein, dolichol, Sertoli, spermatocyte.

2002 ◽  
Vol 282 (6) ◽  
pp. C1492-C1501 ◽  
Author(s):  
R. A. Fenton ◽  
G. J. Cooper ◽  
I. D. Morris ◽  
C. P. Smith

The blood-seminiferous tubule barrier is responsible for maintaining the unique microenvironment conducive to spermatogenesis. A key feature of the blood-testis barrier is selective permeability to solutes and water transport, conferred by the Sertoli cells of the seminiferous tubules (SMTs). Movement of fluid into the lumen of the seminiferous tubule is crucial to spermatogenesis. By Northern analysis, we have shown that 4.0-, 3.3-, 2.8-, and ∼1.7-kb UT-A mRNA transcripts and a 3.8-kb UT-B mRNA transcript are detected within rat testis. Western analysis revealed the expression of both characterized and novel UT-A and UT-B proteins within the testis. Immunolocalization studies determined that UT-A and UT-B protein expression are coordinated with the developmental stage of the SMT. UT-A proteins were detected in Sertoli cell nuclei at all stages of tubule development and in residual bodies of stage VIII tubules. UT-B protein was expressed on Sertoli cell membranes of stage II–III tubules. Using in vitro perfusion, we determined that a phloretin-inhibitable urea pathway exists across the SMTs of rat testis and conclude that UT-B is likely to participate in this pathway.


2010 ◽  
Vol 22 (9) ◽  
pp. 66
Author(s):  
P. K. Nicholls ◽  
P. G. Stanton ◽  
K. L. Walton ◽  
R. I. McLachlan ◽  
L. O'Donnell ◽  
...  

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.


2009 ◽  
Vol 21 (9) ◽  
pp. 32
Author(s):  
S. Danner ◽  
C. Kirchhoff ◽  
R. Ivell

Postmeiotically expressed genes in the testis are essential for the proper progression of spermatogenesis, and yet, aside from the construction of individual transgenic mice using specific promoters to drive reporter plasmids, there are only very limited possibilities for relevant and quantitative analysis of gene promoters. This is due to the special nature of post-meiotic haploid cells, which to date are not represented in any appropriate cell-lines. Here we report the development of novel methodology using isolated and cultured rat seminiferous tubules in a multiwell format, into which promoter-reporter constructs can be introduced by a combination of microinjection and electroporation. Culture conditions were developed which allowed the continued incubation of isolated rat seminiferous tubules for up to 48h without obvious cell death and loss of post-meiotic cells. Transfection of intact seminiferous tubules by microinjection and electroporation was optimized to achieve high expression efficiencies of control plasmids, using either fluorescent protein or luciferase as reporters, thereby allowing both morphological as well as quantitative assessment. Successful transfection was achieved into all cell types except for mature spermatozoa. However, there appeared to be only limited cell-type specificity for the promoters used, even though these had appeared to be specific when used in transgenic animals. We have devised a methodology which allows relatively high throughput analysis of post-meiotic gene promoters into primary cells of intact seminiferous tubules. An apparent lack of cell-type specificity suggests that the gene fragments used do not contain sufficient targeting information, or that the transient episomal expression of the constructs does not encourage appropriate expression specificity. The results also highlight the doubtful interpretation of many studies using heterologous transfection systems to analyse post-meiotically expressed genes.


2018 ◽  
Vol 7 (5) ◽  
pp. 760-770 ◽  
Author(s):  
Oluwajoba O. Akinjo ◽  
Timothy W. Gant ◽  
Emma L. Marczylo

Doxorubicin-induced testicular toxicity involves perturbation of microRNAs within all three of the main testicular cell types, particularly those involved in germ–Sertoli and Sertoli–Sertoli cell junctions.


2017 ◽  
Vol 53 (8) ◽  
pp. 752-758 ◽  
Author(s):  
Maryam Baazm ◽  
Farideh Jalali Mashayekhi ◽  
Saeid Babaie ◽  
Parvindokht Bayat ◽  
Cordian Beyer ◽  
...  

2017 ◽  
Vol 29 (8) ◽  
pp. 1635 ◽  
Author(s):  
A. Dance ◽  
J. Kastelic ◽  
J. Thundathil

Beef and dairy bull calves fed a low-nutrition diet during early life had decreased concentrations of circulating insulin-like growth factor I (IGF-I), delayed increases in testosterone, smaller testes and delayed puberty compared with those fed high-nutrition diets. Although IGF-1 has important roles in Sertoli cell function in rats and mice, this has not been well documented in bulls. The objectives of this study were to: (1) isolate Sertoli cells from bull calves at 8 weeks of age, (2) culture them in vitro and (3) determine the effects of IGF-I, FSH and a combination of both hormones on cell proliferation. For Sertoli cell isolation, minced testicular tissues were treated with collagenase followed by trypsin and hyaluronidase to digest seminiferous tubules and release Sertoli cells. In this study, Sertoli cells were successfully isolated from 8-week-old Holstein bull calves (n = 4) and these cells were cultured for up to 8 days. A combination of IGF-I and FSH increased proliferation (~18%) and therefore cell number (1.5-fold) of prepubertal bovine Sertoli cells in culture, providing clear evidence that IGF-I has a similar role in bovine Sertoli cells as reported in rodents.


1999 ◽  
Vol 145 (5) ◽  
pp. 1027-1038 ◽  
Author(s):  
Antonella Tripiciano ◽  
Carmelina Peluso ◽  
Anna Rita Morena ◽  
Fioretta Palombi ◽  
Mario Stefanini ◽  
...  

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.


Author(s):  
Artem Minin ◽  
Igor Blatov ◽  
Valeria Lebedeva ◽  
Maxim Tuchai ◽  
Varvara Pozdina ◽  
...  

In vitro systems serve as compact and manipulate models to investigate interactions between different cell types. A homogeneous population of cells predictably and uniformly responds to external factors. In a heterogeneous cell population, the effect of external growth factors is perceived in the context of intercellular interactions. Indirect cell co-cultivation allows one to observe the paracrine effects of cells and separately analyze cell populations. The article describes an application of custom-made cell co-cultivation systems based on protein membranes separated from the bottom of the vessel by the 3d printed holder or kept afloat by a magnetic field. Using the proposed co-cultivation system, we analyzed the interaction of A549 cells and fibroblasts, in the presence and absence of growth factors. During co-cultivation of cells, the expression of genes of the activation for epithelial and mesenchymal transitions decreases. The article proposes the application of a newly available system for the co-cultivation of different cell types.


2002 ◽  
Vol 126 (1) ◽  
pp. 64-69
Author(s):  
Manuel Nistal ◽  
María Luisa Riestra ◽  
Ricardo Paniagua

Abstract Objective.—To evaluate seminiferous epithelium lesions in adult cryptorchid testes showing lymphoid infiltrates in seminiferous tubules and interstitium (ie, focal orchitis). Also, to consider the possible role of this lesion in the etiology of tubular atrophy. Methods.—We performed a histopathologic study of the cryptorchid testes and adjacent epididymides removed from 50 adult men who had not been previously treated for cryptorchidism. The study included morphologic and semiquantitative evaluation of seminiferous tubule pathology (according to germ cell numbers), Sertoli cell morphology, tubular lumen dilation, rete testis pattern (normal, hypoplastic, or cystic), and epididymal pattern (normal or epididymal duct hypoplasia). The study also included immunohistochemical evaluation of immune cell markers. The results were compared with clinical and laboratory findings. Results.—Focal lymphoid infiltrates (mainly lymphocytes) in seminiferous tubules and interstitium were found in 22 patients (44%), all of whom had unilateral cryptorchidism. The course of orchitis was asymptomatic, and laboratory data were normal. According to the seminiferous tubule pathology, a variety of histopathologic diagnoses, were made: (1) mixed atrophy consisting of Sertoli cell–only tubules intermingled with tubules showing maturation arrest of spermatogonia (11 testes, 4 of which also showed hyalinized tubules); (2) Sertoli cell–only tubules plus hyalinized tubules (4 testes); (3) Sertoli cell–only tubules (3 testes); (4) intratubular germ cell neoplasia (2 testes, 1 of which also showed hyalinized tubules); (5) complete tubular hyalinization (1 testis); and (6) tubular hyalinization plus some groups of tubules with hypospermatogenesis (all germ cell types were present although in lower numbers, 1 testis). Dysgenetic Sertoli cells, that is, Sertoli cells that had undergone anomalous, incomplete maturation, were observed in all nonhyalinized seminiferous tubules with inflammatory infiltrates. Tubular ectasia was observed in 13 cases. The rete testis was hypoplastic and showed cystic transformation in 18 testes, and the epididymis was hypoplastic in 15 testes. Conclusions.—The causes of these focal inflammatory infiltrates are unknown. It is possible that tubular ectasia and Sertoli cell dysgenesis are involved and that these alterations cause a disruption of the blood-testis barrier and allow antigens to enter the testicular interstitium, giving rise to an autoimmune process.


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