Defective spermatogenesis and testosterone levels in kinase suppressor of Ras1 (KSR1)-deficient mice

2019 ◽  
Vol 31 (8) ◽  
pp. 1369
Author(s):  
Elena Moretti ◽  
Giulia Collodel ◽  
Giuseppe Belmonte ◽  
Daria Noto ◽  
Emanuele Giurisato

The aim of this study was to clarify the role of the protein kinase suppressor of Ras1 (KSR1) in spermatogenesis. Spermatogenesis in ksr1−/− mice was studied in testicular tissue and epididymal spermatozoa by light and transmission electron microscopy and by immunofluorescence using antibodies to ghrelin and 3β-hydroxysteroid dehydrogenase (3β-HSD). Blood testosterone levels were also assessed. ksr1−/− mice showed reduced epididymal sperm concentration and motility as compared with wild-type (wt) mice. Testis tissue from ksr1−/− mice revealed a prevalent spermatogenetic arrest at the spermatocyte stage; the interstitial tissue was hypertrophic and the cytoplasm of the Leydig cells was full of lipid droplets. Ghrelin signal was present in the seminiferous tubules and, particularly, in the interstitial tissue of wt mice; however, in ksr1−/− mice ghrelin expression was very weak in both the interstitial tissue and tubules. On the contrary, the signal of 3β-HSD was weak in the interstitial tissue of wt and strong in ksr1−/− mice. Testosterone levels were significantly increased in the blood of ksr1−/− mice (P<0.05) as compared with wt. The results obtained reveal the importance of the KSR scaffold proteins in the spermatogenetic process. The study of the molecular mechanisms associated with spermatogenetic defects in a mouse model is essential to understand the factors involved in human spermatogenesis.

1974 ◽  
Vol 60 (3) ◽  
pp. 409-419 ◽  
Author(s):  
F. H. de JONG ◽  
A. H. HEY ◽  
H. J. van der MOLEN

SUMMARY Concentrations of oestradiol-17β and testosterone were estimated in testicular tissue from intact and hypophysectomized rats. Within 30 min after intravenous injection of human chorionic gonadotrophin (HCG) or follicle-stimulating hormone (FSH) to intact animals the tissue concentrations of both steroids were not significantly changed. Prolonged s.c. administration of HCG (5 days) caused an increase in the tissue levels of both steroids, which was further increased when the prolonged treatment was followed by an intravenous injection with this trophic hormone. FSH had no influence on tissue concentrations of oestradiol-17β or testosterone in hypophysectomized rats. Assay of separated seminiferous tubules and interstitial tissue indicated that oestradiol-17β and testosterone were mainly localized in the interstitial tissue. Incubations of these constituents showed that oestradiol-17β was produced in the seminiferous tubules, while testosterone was produced in the interstitial compartment.


1974 ◽  
Vol 61 (3) ◽  
pp. 401-410 ◽  
Author(s):  
H. W. A. de BRUIJN ◽  
H. J. van der MOLEN

SUMMARY 17α,20α-Dihydroxy-4-pregnen-3-one is a competitive inhibitor of C17,20-lyase activity in rat testicular tissue in vitro and the significance of this inhibition in vitro was evaluated for testosterone biosynthesis in rat and rabbit testis in vivo. It is concluded that 17α,20α-dihydroxy-4-pregnen-3-one is not involved in the regulation of C17,20-activity in vivo, because it was not possible to detect any 17α,20α-dihydroxy-4-pregnen-3-one in rat and rabbit testicular tissue or in testicular venous blood. If present, the levels are lower than 10 pmol/g testis. Levels of 17α-hydroxyprogester-one are in the order of 50 pmol/g testis. The C17,20-lyase has a higher affinity for 17α-hydroxyprogesterone than for 17α,20α-dihydroxy-4-pregnen-3-one and hence inhibition under in-vivo conditions is not favoured. In rat testes the 20α-hydroxysteroid dehydrogenase activity, which can convert 17α-hydroxyprogesterone to 17α,20α-dihydroxy-4-pregnen-3-one, was found to be mainly (97%) localized in the seminiferous tubules and not at the site of testosterone formation in the interstitial tissue.


2020 ◽  
pp. 1-3
Author(s):  
◽  
◽  
◽  

Objective: In this study we purposed to explore seminiferous tubules via histopathological and electron microscopic methods in testicular biopsy samples obtained TESE and the relationship between the findings and levels of serum FSH, LH, testosterone hormones. Methods: Azoospermia patients were divided into two groups, a positive testicular sperm extraction (TESE(+)) and a negative testicular sperm extraction (TESE(-)). Testicular tissue from biopsy samples were subjected to the light and electron microscopic tissue preparations. Serum hormone levels of patients were determined and analyzed statistically between the groups. Results: Compared the groups, more remarkable damages were detected in the seminiferous tubulus of no sperm group in the light and electron microscopic examinations. Although inflammation and partly tubule degeneration was observed, spermatogenesis and sperm cells were determined in the tubules of sperm pozitive group. In the light and ultrastructural analysis of negative sperm group, macrophages and mast cells in the interstitial tissue, vacuolization of seminiferous tubules, lipid inclusions and Sertoli cell only syndrome were the significant findings. When analyzed serum FSH, LH and testosterone hormones between the groups, FSH and LH hormones were statistically significant while Testosteron hormone was not significant. Conclusion: As a result in the seminiferous tubules of individuals histopathological results revealed that FSH and LH are important indicator of testicular function but Testosteron has not any effect. It was concluded that high levels of these hormones impair spermatogenesis and cause testicular failure.


2014 ◽  
Vol 26 (6) ◽  
pp. 817 ◽  
Author(s):  
Lucía Arregui ◽  
Ina Dobrinski ◽  
Eduardo R. S. Roldan

The use of assisted reproductive techniques for endangered species is a major goal for conservation. One of these techniques, testis tissue xenografting, allows for the development of spermatozoa from animals that die before reaching sexual maturity. To assess the potential use of this technique with endangered species, testis tissue from six Iberian lynxes (one fetus, two perinatal cubs, two 6-month-old and one 2-year-old lynx), two Cuvier’s gazelle fetuses and one 8-month-old Mohor gazelle were transplanted ectopically into nude mice. Tissue from the lynx fetus, perinatal cubs and 2-year-old donors degenerated, whereas spermatogonia were present in 15% of seminiferous tubules more than 70 weeks after grafting in transplanted testis tissue from 6-month-old donors. Seminal vesicle weights (indicative of testosterone production) increased over time in mice transplanted with tissue from 6-month-old lynxes. Progression of spermatogenesis was observed in xenografts from gazelles and was donor age dependent. Tissue from Cuvier’s gazelle fetuses contained spermatocytes 40 weeks after grafting. Finally, round spermatids were found 28 weeks after transplantation in grafts from the 8-month-old Mohor gazelle. This is the first time that xenotransplantation of testicular tissue has been performed with an endangered felid and the first successful xenotransplantation in an endangered species. Our results open important options for the preservation of biological diversity.


2021 ◽  
Author(s):  
Meghan Alice Robinson ◽  
Erin Bedford ◽  
Luke Witherspoon ◽  
Stephanie Willerth ◽  
Ryan Flannigan

Advances in cancer treatments have greatly improved pediatric cancer survival rates, leading to quality of life considerations and in particular fertility restoration. Accordingly, pre-pubertal patients have the option to cryopreserve testicular tissue for experimental restorative therapies, including in vitro spermatogenesis, wherein testicular tissue is engineered in vitro and spermatozoa are collected for in vitro fertilization (IVF). Current in vitro systems have been unable to reliably support the generation of spermatozoa from human testicular tissues, likely due to the inability for the dissociated testicular cells to recreate the native architecture of testicular tissue found in vivo. Recent advances in 3-D bioprinting can place cells into geometries at fine resolutions comparable to microarchitectures found in native tissues, and therefore hold promise as a tool for the development of a biomimetic in vitro system for human spermatogenesis. This study assessed the utility of bioprinting technology to recreate the precise architecture of testicular tissue and corresponding spermatogenesis for the first time. We printed testicular cell-laden hollow microtubules at similar resolutions to seminiferous tubules, and compared the results to testicular organoids. We show that the human testicular cells retain their viability and functionality post-printing, and illustrate an intrinsic ability to reorganize into their native cytoarchitecture. This study provides a proof of concept for the use of 3-D bioprinting technology as a tool to create biomimetic human testicular tissues.


Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Camila Dores ◽  
Ina Dobrinski

De novo formation of testis tissue from single-cell suspensions allows manipulation of different testicular compartments before grafting to study testicular development and the spermatogonial stem cell niche. However, the low percentages of newly formed seminiferous tubules supporting complete spermatogenesis and lack of a defined protocol have limited the use of this bioassay. Low spermatogenic efficiency in de novo formed tissue could result from the scarcity of germ cells in the donor cell suspension, cell damage caused by handling or from hypoxia during tissue formation in the host environment. In this study, we compared different proportions of spermatogonia in the donor cell suspension and the use of Matrigel as a scaffold to support de novo tissue formation and spermatogenesis. Then, we used the system to investigate the role of vascular endothelial growth factor 165 (VEGF165) during testicular morphogenesis on blood vessel and seminiferous tubule formation, and on presence of germ cells in the de novo developed tubules. Our results show that donor cell pellets with 10×106 porcine neonatal testicular cells in Matrigel efficiently formed testis tissue de novo. Contrary to what was expected, the enrichment of the cell suspension with germ cells did not result in higher numbers of tubules supporting spermatogenesis. The addition of VEGF165 did not improve blood vessel or tubule formation, but it enhanced the number of tubules containing spermatogonia. These results indicate that spermatogenic efficiency was improved by the addition of Matrigel, and that VEGF165 may have a protective role supporting germ cell establishment in their niche.


2005 ◽  
Vol 21 (9) ◽  
pp. 249-254 ◽  
Author(s):  
Oğuz Aslan Özen ◽  
Nusret Akpolat ◽  
Ahmet Songur ◽  
İlter Kuş ◽  
İsmail Zararsiz ◽  
...  

One parameter which might provide an insight into the underlying mechanism of the effect of formaldehyde (FA) inhalation on testicular tissue, is the assessment of heat shock protein 70 (Hsp70), which increases promptly in cells exposed to stress caused by chemical toxicity. Thus, following subchronic exposure at cytotoxic concentrations, we studied the immunohistochemical effect of FA inhalation on changes in Hsp70 content in testicular tissue. We used 18 albino Wistar rats divided into three groups, exposed to 0 (control), 5 and 10 ppm FA gas for a total of 91 days, 8 h/day, five days a week. Serum testosterone levels were determined using a chemiluminescent enzyme immunoassay. Testicular tissues were stained with Hematoxylin-Eosine and Hsp70 immunohistochemically performed. Diameters of seminiferous tubules and serum testosterone levels in animals inhaling FA were significantly decreased. In seminiferous epithelium stained for Hsp70, compared to those in the control group, the spermatogenetic cells in the experimental groups demonstrated an obvious increase in immunoreaction spermatides in the adluminal region and especially in the cytoplasm of spermatocytes. Immunoreaction of Hsp70 was detected in the spermatogonias of animals exposed to FA inhalation as opposed to those of the control group. Compared to the control, there was a significant increase in the immunoreactions observed not only in the cytoplasm of primary spermatocytes, but also spermatides in the adluminal region of the seminiferous tubules. In conclusion, FA gas may damage spermatogenetic cells and increase Hsp70 synthesis.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A771-A771
Author(s):  
Geetika Bassi ◽  
Suresh Mishra

Abstract Testosterone, the male sex hormone, plays an important role in the sexual development and fertility. Consequently, its deficiency causes infertility, obesity, osteoporosis and cardiovascular diseases. Leydig cells (LCs) are the testicular interstitial cells responsible for the biosynthesis of testosterone in response to luteinizing hormone (LH) from the pituitary. Cholesterol is the essential substrate for steroidogenesis which is translocated from the cytosol to the mitochondria where it gets converted to pregnenolone (by P450 side chain cleavage enzyme). Subsequently, pregnenolone translocate to endoplasmic reticulum where action of various enzymes results in the biosynthesis of testosterone. Prohibitin-1 (PHB1) is an evolutionary conserved ubiquitously expressed protein with cell compartment and cell-type specific functions. Mitochondrial function of PHB1 has been widely studied but its role in testicular steroidogenesis is unexplored. Recently, we have reported two transgenic mice models of PHB1, PHB-Tg and mutant-PHB-Tg (mPHB-Tg), expressing PHB1 or Y114F (mutant PHB1) respectively under the control of Fabp-4 gene promoter. During phenotypic characterization of these mice models, we observed a drastic size/weight difference in the testis of PHB-Tg and mPHB-Tg when compared with wild type mice. The mPHB-Tg mice testis was significantly smaller than the PHB-Tg and wild type mice. Further analysis of mPHB-Tg testis revealed wider testicular interstitium with LC hyperplasia and elongated seminiferous tubules. Ultrastructure investigation revealed that LCs of mPHB-Tg mice have prominent nucleus with increased number of mitochondria and lipid droplets. In addition, electron microscopic images of mPHB-Tg mice LCs revealed a sign of lipophagy and mitophagy. This prompted us to measure testosterone levels in these mice; surprisingly mPHB-Tg mice showed significantly higher testosterone levels as compared to PHB-Tg and wild type mice. Furthermore, testicular lysates and primary LCs cell lysates from transgenic mice models revealed that overexpression of PHB/mPHB in LCs inversely effect expression levels of steroidogenic acute regulatory protein (StAR). Moreover, co-immunoprecipitation of PHB1 displayed an interaction with StAR, P450scc and LC3 further revealing a key role of PHB1 in cholesterol translocation, testicular steroidogenesis and autophagy. Taken together, this finding suggests that PHB1 plays a multifaceted role in testicular steroidogenesis from determining testis size to the translocation of cholesterol into the mitochondria, in maintaining lipid homeostasis and biosynthesis of testosterone. Implications of our findings are broad because cholesterol translocation to the mitochondria and its subsequent utilization for steroidogenesis is conserved in all steroidogenic tissues.


1990 ◽  
Vol 125 (3) ◽  
pp. 485-NP ◽  
Author(s):  
S. C. Stubbs ◽  
T. B. Hargreave ◽  
F. K. Habib

ABSTRACT In the present study attempts were made to characterize the epidermal growth factor (EGF) receptor on human testicular tissue. A radioligand exchange assay with 125I-labelled EGF was used to detect a high affinity, low capacity, single binding site in the 105 000 g particulate fraction of human testicular tissue. Binding was optimal at 32 °C following a 40-min incubation with a mean ( ± s.d.) dissociation constant of 327 ±59 pmol/l (d.f. 9). The number of binding sites ranged from 0.07 to 0.21 pmol/mg protein. Competition studies with other peptide hormones including LH, FSH, prolactin, insulin-like growth factor-I, fibroblast growth factor and nerve growth factor have confirmed the specificity of EGF for its receptor. The receptor was also found to be heatlabile and sensitive to trypsinization. Cross-linking experiments using disuccinimidyl suberate revealed major binding species at the 125 kDa region and this is thought to represent a proteolysed form of the receptor. Immunohistochemical localization of the receptors demonstrated their presence in the interstitial tissue and not within the seminiferous tubules. The presence of specific EGF binding in the interstitial tissue suggests that EGF may play some role in testicular steroidogenesis. Journal of Endocrinology (1990) 125, 485–492


2010 ◽  
Vol 22 (4) ◽  
pp. 673 ◽  
Author(s):  
Regina M. Turner ◽  
Rahul Rathi ◽  
Ali Honaramooz ◽  
Wenxian Zeng ◽  
Ina Dobrinski

Spermatogenesis from many mammalian species occurs in fragments of normal testis tissue xenografted to mice. Here we apply xenografting to the study of testicular pathology. Using the horse model, we investigated whether exposure to a permissive extratesticular environment in the mouse host would rescue spermatogenesis in cryptorchid testicular tissue or in tissue affected by idiopathic testicular degeneration (ITD). In cryptorchid tissue, where the extratesticular environment is abnormal, xenografting induced spermatogenesis up to meiosis in a subpopulation of seminiferous tubules. Thus, spermatogonia survive and partially retain their potential to differentiate in cryptorchid horse testes. In contrast, the primary defect in equine ITD is hypothesised to be tissue autologous. In support of this, xenografting did not restore spermatogenesis to tissue affected by ITD, thus confirming that the testis itself is primarily diseased. This outcome was not affected by supplementation of exogenous gonadotropins to the mouse host or by reconstitution of a normal reproductive regulatory axis supplied by functional porcine testicular xenografts. These studies demonstrate the usefulness of xenografting for the study of testicular pathology.


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