The effect of germ cell complement on the presence of oxytocin in the interstitial and seminiferous tubule fluid of the rat testis

1994 ◽  
Vol 143 (3) ◽  
pp. 471-478 ◽  
Author(s):  
H D Nicholson ◽  
H M Greenfield ◽  
J Frayne
Keyword(s):  
Heat Treatment ◽  
Germ Cell ◽  
Germ Cells ◽  
Seminiferous Tubule ◽  
Leydig Cells ◽  
Male Rats ◽  
Rat Testis ◽  
Pachytene Spermatocytes ◽  
Tubule Fluid

Abstract In the rat testis oxytocin has been localized to the Leydig cells, and these cells have been shown to produce oxytocin in vitro. The present study was performed to determine whether oxytocin is present in the interstitial fluid (IF) and seminiferous tubule fluid (TF) of the rat and whether concentrations of the peptide vary within the two compartments following germ cell destruction. In order to destroy germ cells adult male rats were anaesthetized and their scrotal regions placed in a water bath at 43 °C for 20 min. Control animals were subjected to anaesthesia alone. Groups of 6 animals were killed 3, 7 and 21 days after heat treatment and their testes removed for histological examination or fluid extraction. IF and TF were separated and the oxytocin content of the fluids measured by radioimmunoassay. Immunoreactive oxytocin was detected in both the IF (100 ±11 pg/ml) and TF (27± 4 pg/ml) of control rats and this immunoreactivity co-eluted with the authentic peptide following HPLC. Three days after heat treatment IF levels of oxytocin were significantly reduced but TF levels of the peptide were significantly increased. These changes were associated with a lack of pachytene spermatocytes in the histological sections. Seven and 21 days after heat treatment the levels of oxytocin in the IF and TF were not significantly different from control levels. Similar changes in IF and TF oxytocin levels were seen in a second experiment when pachytene spermatocytes were removed using the testicular toxicant methoxyacetic acid. To investigate whether oxytocin passes from the IF into the TF, 3H-oxytocin was infused into the testicular arteries of both control and heat-treated rats and the rats killed at regular intervals over the next 24 h. In both groups of animals <5% of the 3H-oxytocin passed from the IF into the TF. These data suggest that the seminiferous tubule as well as the Leydig cells may secrete oxytocin and that this secretion may be influenced by the presence of germ cells, particularly pachytene spermatocytes. Journal of Endocrinology (1994) 143, 471–478

scholarly journals Hepatocyte growth factor modulates in vitro survival and proliferation of germ cells during postnatal testis development

2006 ◽  
Vol 189 (1) ◽  
pp. 137-146 ◽  
Author(s):  
A Catizone ◽  
G Ricci ◽  
J Del Bravo ◽  
M Galdieri
Keyword(s):  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Types ◽  
Tyrosine Kinase Receptor ◽  
Testis Development ◽  
Pachytene Spermatocytes ◽  
Hepatocyte Growth

The hepatocyte growth factor (HGF) is a pleiotropic cytokine that influences mitogenesis, motility and differentiation of many different cell types by its tyrosine kinase receptor c-Met. We previously demonstrated that the c-Met/HGF system is present and functionally active during postnatal testis development. We found also that spermatozoa express c-Met and that HGF has a positive effect on the maintenance of sperm motility. In the present paper, we extend our study on the germ cells at different stages of differentiation during the postnatal development of the testis. We demonstrate that c-met is present in rat spermatogonia, pachytene spermatocytes and round spermatids and that HGF significantly increases spermatogonial proliferation in 8- to 10-day-old pre-pubertal rats. At this age HGF does not affect Sertoli cells and peritubular myoid cells proliferation. In addition, we studied the effect of the factor on germ cell apoptosis and we show that HGF prevents the germ cell apoptotic process. We also studied the effect of HGF on 18- to 20-day-old and 28- to 30-day-old rat testes. At these ages also the factor significantly increases germ cell duplication and decreases the number of apoptotic cells. However, the effect on programmed cell death is higher in the 8- to 10-day-old rats and declines in the older animals. In conclusion, we report that rat germ cells (spermatogonia, pachytene spermatocytes and round spermatids) express c-met and that HGF modulates germ cell proliferating activity and apoptosis in vitro. These data indicate that the c-Met/HGF system is involved in male germ cell homeostasis and, consequently, has a role in male fertility.

scholarly journals Testosterone regulates granzyme K expression in rat testes

2017 ◽  
Vol 51 (4) ◽  
pp. 193-204 ◽  
Author(s):  
Dibyendu Dutta ◽  
In Park ◽  
Hiwot Guililat ◽  
Samuel Sang ◽  
Arpita Talapatra ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cell Apoptosis ◽  
Seminiferous Tubule ◽  
Serine Proteases ◽  
Leydig Cells ◽  
Seminiferous Tubules ◽  
Germ Cell Apoptosis ◽  
Tubule Lumen ◽  
Premature Release

Abstract Objective. Testosterone depletion induces increased germ cell apoptosis in testes. However, limited studies exist on genes that regulate the germ cell apoptosis. Granzymes (GZM) are serine proteases that induce apoptosis in various tissues. Multiple granzymes, including GZMA, GZMB and GZMN, are present in testes. Th us, we investigated which granzyme may be testosterone responsive and possibly may have a role in germ cell apoptosis aft er testosterone depletion. Methods. Ethylene dimethane sulfonate (EDS), a toxicant that selectively ablates the Leydig cells, was injected into rats to withdraw the testosterone. The testosterone depletion effects after 7 days post-EDS were verified by replacing the testosterone exogenously into EDS-treated rats. Serum or testicular testosterone was measured by radioimmunoassay. Using qPCR, mRNAs of granzyme variants in testes were quantified. The germ cell apoptosis was identified by TUNEL assay and the localization of GZMK was by immunohistochemistry. Results. EDS treatment eliminated the Leydig cells and depleted serum and testicular testosterone. At 7 days post-EDS, testis weights were reduced 18% with increased germ cell apoptosis plus elevation GZMK expression. GZMK was not associated with TUNEL-positive cells, but was localized to stripped cytoplasm of spermatids. In addition, apoptotic round spermatids were observed in the caput epididymis. Conclusions. GZMK expression in testes is testosterone dependent. GZMK is located adjacent to germ cells in seminiferous tubules and the presence of apoptotic round spermatids in the epididymis suggest its role in the degradation of microtubules in ectoplasmic specializations. Thus, overexpression of GZMK may indirectly regulate germ cell apoptosis by premature release of round spermatids from seminiferous tubule lumen.

scholarly journals Hedgehog signalling promotes germ cell survival in the rat testis

Reproduction ◽  
2011 ◽  
Vol 142 (5) ◽  
pp. 711-721 ◽  
Author(s):  
Juho-Antti Mäkelä ◽  
Vuokko Saario ◽  
Sonia Bourguiba-Hachemi ◽  
Mirja Nurmio ◽  
Kirsi Jahnukainen ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Germ Cell ◽  
Germ Cells ◽  
Tyrosine Kinases ◽  
Negative Regulator ◽  
Mrna Levels ◽  
Paracrine Signalling ◽  
Rat Testis ◽  
Germ Cell Differentiation

Hedgehog (Hh) signalling has a crucial role in testis development. Sertoli cell-derived desert hedgehog (DHH) guides the formation of testis cords and differentiation of foetal-type Leydig cells. Dhh mutant mice are infertile due to a block in germ cell differentiation, hypogonadism and hypoandrogenism. Hh signalling pathway components are also expressed in postnatal testis. In the rat testis the transcription factor of the Hh pathway, glioma-associated oncogene homologue (GLI1), is expressed by a wide variety of germ cells. This suggests that Hh signalling is involved in spermatogenesis at many different levels. Our data show that canonical Hh signalling is turned off in early condensing spermatids that strongly express the negative regulator of the pathway, suppressor of fused (SUFU). Most of the Hh pathway specific mRNAs display the highest values in stages II–VI of the rat seminiferous epithelial cycle. The key endocrine regulator of germ cell differentiation, FSH, down-regulates Dhh mRNA levels in vitro. Hh signalling inhibition in vitro leads to massive apoptosis of germ cells. In prepubertal rat testis imatinib mesylate-induced inhibition of tyrosine kinases impinges on Dhh transcript levels and Hh signalling. Our data indicate that Hh signalling is part of the paracrine signalling network in the rat testis. It promotes the survival of germ cells and is suppressed by FSH.

scholarly journals Endogenous EGF maintains Sertoli germ cell anchoring junction integrity and is required for early recovery from acute testicular ischemia/reperfusion injury

Reproduction ◽  
2013 ◽  
Vol 145 (2) ◽  
pp. 177-189 ◽  
Author(s):  
Shun Zhang ◽  
Yi Zeng ◽  
Juan Qu ◽  
Yaning Luo ◽  
Xiaohong Wang ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Intracellular Signaling ◽  
Egf Receptor ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Acute Ischemia ◽  
Early Recovery ◽  
Pachytene Spermatocytes

Administration of exogenous epidermal growth factor (EGF) improves testicular injury after acute ischemia–reperfusion (IR) stress, but the molecular basis is poorly understood. The role of endogenous EGF in testicular recovery and the underlying intracellular signaling pathways involved were herein investigated. In mice, testicular IR injury significantly enhanced the expression level of endogenousEgfat the very beginning of reperfusion. Expression of EGF receptor (Egfr(ErbB1)) was accordingly upregulated 3 h after reperfusion. Deprivation of majority of circulated EGF by sialoadenectomy aggravated testicular detriment (especially in pachytene spermatocytes), enhanced germ cell apoptosis, and thereafter resulted in impaired meiotic differentiation after IR insult. Mechanistically, endogenous EGF signaling appeared to be indispensable for the proper maintenance of Sertoli germ cells anchoring junction dynamics during the early testicular recovery. We also provided thein vitroevidences in a well-established rat Sertoli germ cell co-cultures model that the pro-survival effect of endogenous EGF on germ cells in response to testicular IR insult is mediated, at least in part, via the phosphatidylinositol 3-kinase/pAkt pathway. Collectively, our results suggest that the augment of endogenous EGF during the early testicular recovery may act on top of an endocrinous cascade orchestrating the intimate interactions between Sertoli cells and germ cells and may operate as indispensable defensive mechanism in response to testicular IR stress. Future studies in this field would shed light on this complicated pathogenesis.

scholarly journals Effects of Hexachlorocyclohexane (HCH-γ-Isomer, Lindane) Intoxication on the Proliferation and Apoptosis in Rat Testes

2009 ◽  
Vol 78 (4) ◽  
pp. 615-620 ◽  
Author(s):  
Hayati Yuksel ◽  
Erkan Karadas ◽  
Hikmet Keles ◽  
Hasan Huseyin Demirel
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Male Rats ◽  
Control Group ◽  
High Dose ◽  
Histopathological Changes ◽  
Proliferation And Apoptosis ◽  
Group A ◽  
Higher Doses ◽  
Group 1

In this study, experimentally lindane-induced histopathological changes and proliferation and/or apoptosis in germ cells in the rat testes were investigated. A total of 40 healthy fertile 3-month-old male rats were used. Animals were divided into 4 groups, each containing 10 rats. Group 1 (control) was given only pure olive oil, Groups 2, 3 and 4 were administered lindane at 10, 20 and 40 mg/kg/bw, respectively, by gastric gavage for 30 days. Microscopically, degenerative changes were observed in the lindane-treated groups. For proliferative activity PCNA immunolabelling and for germ cells apoptosis TUNEL methods were performed. Although a strong PCNA positivity in the control group was observed, a gradual decrease was noted in the lindane-treated groups especially at higher doses. Significant increases of apoptosis were seen in the lindane-treated groups compared to the control group. A decrease in testosterone concentrations was observed in lindane-treated groups compared to the control group. The study indicates that high-dose lindane intoxication contributes to the suppression of spermatogenesis through a reduction of germ cell proliferation and an increase of germ cell death in rat testes.

Effects of hypophysectomy and subsequent FSH and testosterone treatment on inhibin production by adult rat testes

1985 ◽  
Vol 105 (1) ◽  
pp. 1-6 ◽  
Author(s):  
C. L. Au ◽  
D. M. Robertson ◽  
D. M. de Kretser
Keyword(s):  
Seminiferous Tubule ◽  
Hormonal Control ◽  
Human Chorionic Gonadotrophin ◽  
Experimental Conditions ◽  
Adult Rats ◽  
Adult Rat ◽  
Fluid Production ◽  
Tubule Fluid

ABSTRACT The hormonal control of inhibin production by adult rat testes was investigated using an in-vitro inhibin bioassay validated for the measurement of inhibin activity in charcoal-treated rat testicular extracts. The effect of hypophysectomy examined at 16 h, 3, 7 and 42 days after surgery showed a decrease in testicular inhibin content and seminiferous tubule fluid production by 7 days and a decrease in inhibin production by 42 days. Serum FSH and LH were suppressed 3 days after surgery. In 30-day chronically hypophysectomized adult rats treated for 3 days with twice daily s.c. injections of (a) human FSH (hFSH, 22 i.u./rat per day), (b) testosterone (5 mg/rat per day), (c) hFSH + testosterone (same doses as a and b), or (d) human chorionic gonadotrophin (hCG, 12 i.u./rat per day), hFSH or hFSH and testosterone stimulated an increase in testicular inhibin content but not in inhibin production or tubule fluid production. Testosterone and hCG had no effect on these parameters. It is concluded that in vivo, FSH alone stimulates an increase in testicular inhibin content. The failure to observe an increase in inhibin production in vivo is attributed to the suppression of seminiferous tubule fluid production under the same experimental conditions. J. Endocr. (1985) 105, 1–6

scholarly journals Ligand–Receptor Interactions Elucidate Sex-Specific Pathways in the Trajectory From Primordial Germ Cells to Gonia During Human Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Arend W. Overeem ◽  
Yolanda W. Chang ◽  
Jeroen Spruit ◽  
Celine M. Roelse ◽  
Susana M. Chuva De Sousa Lopes
Keyword(s):  
Germ Cell ◽  
Signaling Pathways ◽  
Germ Cells ◽  
Tyrosine Kinases ◽  
Intracellular Localization ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Systematic Analysis ◽  
Receptor Interactions

The human germ cell lineage originates from primordial germ cells (PGCs), which are specified at approximately the third week of development. Our understanding of the signaling pathways that control this event has significantly increased in recent years and that has enabled the generation of PGC-like cells (PGCLCs) from pluripotent stem cells in vitro. However, the signaling pathways that drive the transition of PGCs into gonia (prospermatogonia in males or premeiotic oogonia in females) remain unclear, and we are presently unable to mimic this step in vitro in the absence of gonadal tissue. Therefore, we have analyzed single-cell transcriptomics data of human fetal gonads to map the molecular interactions during the sex-specific transition from PGCs to gonia. The CellPhoneDB algorithm was used to identify significant ligand–receptor interactions between germ cells and their sex-specific neighboring gonadal somatic cells, focusing on four major signaling pathways WNT, NOTCH, TGFβ/BMP, and receptor tyrosine kinases (RTK). Subsequently, the expression and intracellular localization of key effectors for these pathways were validated in human fetal gonads by immunostaining. This approach provided a systematic analysis of the signaling environment in developing human gonads and revealed sex-specific signaling pathways during human premeiotic germ cell development. This work serves as a foundation to understand the transition from PGCs to premeiotic oogonia or prospermatogonia and identifies sex-specific signaling pathways that are of interest in the step-by-step reconstitution of human gametogenesis in vitro.

scholarly journals Interactome analyses reveal profound proteasome structural and functional rearrangements throughout mammalian spermatogenesis

2021 ◽  
Author(s):  
Dusan Zivkovic ◽  
Angelique Sanchez Dafun ◽  
Thomas Menneteau ◽  
Adrien Schahl ◽  
Sandrine Lise ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Germ Cell ◽  
Germ Cells ◽  
Protein Assembly ◽  
Homologous Chromosomes ◽  
High Proteolytic Activity ◽  
Complex Processes ◽  
Germ Cell Differentiation ◽  
Mechanism Function

During spermatogenesis, spermatogonia undergo a series of mitotic and meiotic divisions on their path to spermatozoa. To achieve this, a succession of complex processes requiring high proteolytic activity are in part orchestrated by the proteasome. The spermatoproteasome (s20S) is a proteasome subtype specific to the developing gametes, in which the gamete-specific α4s subunit replaces the α4 isoform found in the constitutive proteasome (c20S). Although the s20S is conserved across species and was shown to be crucial for germ cell development, its mechanism, function and structure remain incompletely characterized. Here, we used advanced mass spectrometry (MS) methods to map the composition of proteasome complexes and their interactomes throughout spermatogenesis. We observed that the s20S becomes highly activated as germ cells enter meiosis, mainly through association with proteasome activators PA200 and 19S. Additionally, the proteasome population shifts from predominantly c20S (98%) to predominantly s20S (>82-92%) during differentiation, presumably due to the shift from α4 to α4s expression. We confirmed that s20S, but not c20S, interacts with components of the synaptonemal complex, the multi-protein assembly that connects homologous chromosomes during meiosis. In vitro, s20S preferentially bind to 19S, and displayed higher trypsin- and chymotrypsin-like activities, both with and without PA200 activation. Moreover, using MS methods to monitor protein dynamics, we identified significant differences in domain flexibility between α4 and α4s. We propose that these differences induced by α4s incorporation result in significant changes in the way the s20S interacts with its partners, and dictate its role in germ cell differentiation.

scholarly journals Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis

Reproduction ◽  
2009 ◽  
Vol 138 (4) ◽  
pp. 667-677 ◽  
Author(s):  
Kyle C Caires ◽  
Jeanene de Avila ◽  
Derek J McLean
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Germ Cell ◽  
Cell Survival ◽  
Germ Cells ◽  
Pcr Analysis ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor ◽  
Testis Tissue

Vascular endothelial growth factor-A (VEGFA) is a hypoxia-inducible peptide essential for angiogenesis and targets nonvascular cells in a variety of tissues and cell types. The objective of the current study was to determine the function of VEGF during testis development in bulls. We used an explant tissue culture and treatment approach to test the hypothesis that VEGFA-164 could regulate the biological activity of bovine germ cells. We demonstrate that VEGFA, KDR, and FLT1 proteins are expressed in germ and somatic cells in the bovine testis. Treatment of bovine testis tissue with VEGFA in vitro resulted in significantly more germ cells following 5 days of culture when compared with controls. Quantitative real-time RT-PCR analysis determined that VEGF treatment stimulated an intracellular response that prevents germ cell death in bovine testis tissue explants, as indicated by increased expression of BCL2 relative to BAX and decreased expression of BNIP3 at 3, 6, and 24 h during culture. Blocking VEGF activity in vitro using antisera against KDR and VEGF significantly reduced the number of germ cells in VEGF-treated testis tissue to control levels at 120 h. Testis grafting provided in vivo evidence that bovine testis tissue treated with VEGFA for 5 days in culture contained significantly more differentiating germ cells compared with controls. These findings support the conclusion that VEGF supports germ cell survival and sperm production in bulls.

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