scholarly journals Regulation of GDNF expression in Sertoli cells

Reproduction ◽  
2019 ◽  
Author(s):  
Parag Parekh ◽  
Thomas Xavier Garcia ◽  
Marie-claude Hofmann

Sertoli cells regulate male germ cell proliferation and differentiation and are a critical component of the spermatogonial stem cell (SSC) niche, where homeostasis is maintained by the interplay of several signaling pathways and growth factors. These factors are secreted by Sertoli cells located within the seminiferous epithelium, and by interstitial cells residing between the seminiferous tubules. Sertoli cells and peritubular myoid cells produce glial cell line-derived neurotrophic factor (GDNF), which binds to the RET/GFRA1 receptor complex at the surface of undifferentiated spermatogonia. GDNF is known for its ability to drive SSC self-renewal and proliferation of their direct cell progeny. Even though the effects of GDNF are well studied, our understanding of the regulation its expression is still limited. The purpose of this review is to discuss how GDNF expression in Sertoli cells is modulated within the niche, and how these mechanisms impact germ cell homeostasis.

Reproduction ◽  
2015 ◽  
Vol 149 (3) ◽  
pp. R139-R157 ◽  
Author(s):  
Gurpreet Manku ◽  
Martine Culty

The production of spermatozoa relies on a pool of spermatogonial stem cells (SSCs), formed in infancy from the differentiation of their precursor cells, the gonocytes. Throughout adult life, SSCs will either self-renew or differentiate, in order to maintain a stem cell reserve while providing cells to the spermatogenic cycle. By contrast, gonocytes represent a transient and finite phase of development leading to the formation of SSCs or spermatogonia of the first spermatogenic wave. Gonocyte development involves phases of quiescence, cell proliferation, migration, and differentiation. Spermatogonia, on the other hand, remain located at the basement membrane of the seminiferous tubules throughout their successive phases of proliferation and differentiation. Apoptosis is an integral part of both developmental phases, allowing for the removal of defective cells and the maintenance of proper germ–Sertoli cell ratios. While gonocytes and spermatogonia mitosis are regulated by distinct factors, they both undergo differentiation in response to retinoic acid. In contrast to postpubertal spermatogenesis, the early steps of germ cell development have only recently attracted attention, unveiling genes and pathways regulating SSC self-renewal and proliferation. Yet, less is known on the mechanisms regulating differentiation. The processes leading from gonocytes to spermatogonia have been seldom investigated. While the formation of abnormal gonocytes or SSCs could lead to infertility, defective gonocyte differentiation might be at the origin of testicular germ cell tumors. Thus, it is important to better understand the molecular mechanisms regulating these processes. This review summarizes and compares the present knowledge on the mechanisms regulating mammalian gonocyte and spermatogonial differentiation.


Reproduction ◽  
2015 ◽  
Vol 149 (4) ◽  
pp. R159-R167 ◽  
Author(s):  
Su-Ren Chen ◽  
Yi-Xun Liu

Spermatogenesis is a continuous and productive process supported by the self-renewal and differentiation of spermatogonial stem cells (SSCs), which arise from undifferentiated precursors known as gonocytes and are strictly controlled in a special ‘niche’ microenvironment in the seminiferous tubules. Sertoli cells, the only somatic cell type in the tubules, directly interact with SSCs to control their proliferation and differentiation through the secretion of specific factors. Spermatocyte meiosis is another key step of spermatogenesis, which is regulated by Sertoli cells on the luminal side of the blood–testis barrier through paracrine signaling. In this review, we mainly focus on the role of Sertoli cells in the regulation of SSC self-renewal and spermatocyte meiosis, with particular emphasis on paracrine and endocrine-mediated signaling pathways. Sertoli cell growth factors, such as glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2), as well as Sertoli cell transcription factors, such as ETS variant 5 (ERM; also known as ETV5), nociceptin, neuregulin 1 (NRG1), and androgen receptor (AR), have been identified as the most important upstream factors that regulate SSC self-renewal and spermatocyte meiosis. Other transcription factors and signaling pathways (GDNF–RET–GFRA1 signaling, FGF2–MAP2K1 signaling, CXCL12–CXCR4 signaling, CCL9–CCR1 signaling, FSH–nociceptin/OPRL1, retinoic acid/FSH–NRG/ERBB4, and AR/RB–ARID4A/ARID4B) are also addressed.


2015 ◽  
Vol 29 (4) ◽  
pp. 627-642 ◽  
Author(s):  
Céline Zimmermann ◽  
Isabelle Stévant ◽  
Christelle Borel ◽  
Béatrice Conne ◽  
Jean-Luc Pitetti ◽  
...  

Abstract Sertoli cells (SCs), the only somatic cells within seminiferous tubules, associate intimately with developing germ cells. They not only provide physical and nutritional support but also secrete factors essential to the complex developmental processes of germ cell proliferation and differentiation. The SC transcriptome must therefore adapt rapidly during the different stages of spermatogenesis. We report comprehensive genome-wide expression profiles of pure populations of SCs isolated at 5 distinct stages of the first wave of mouse spermatogenesis, using RNA sequencing technology. We were able to reconstruct about 13 901 high-confidence, nonredundant coding and noncoding transcripts, characterized by complex alternative splicing patterns with more than 45% comprising novel isoforms of known genes. Interestingly, roughly one-fifth (2939) of these genes exhibited a dynamic expression profile reflecting the evolving role of SCs during the progression of spermatogenesis, with stage-specific expression of genes involved in biological processes such as cell cycle regulation, metabolism and energy production, retinoic acid synthesis, and blood-testis barrier biogenesis. Finally, regulatory network analysis identified the transcription factors endothelial PAS domain-containing protein 1 (EPAS1/Hif2α), aryl hydrocarbon receptor nuclear translocator (ARNT/Hif1β), and signal transducer and activator of transcription 1 (STAT1) as potential master regulators driving the SC transcriptional program. Our results highlight the plastic transcriptional landscape of SCs during the progression of spermatogenesis and provide valuable resources to better understand SC function and spermatogenesis and its related disorders, such as male infertility.


2012 ◽  
Vol 209 (5) ◽  
pp. 895-901 ◽  
Author(s):  
Olivier Herault ◽  
Kristin J. Hope ◽  
Eric Deneault ◽  
Nadine Mayotte ◽  
Jalila Chagraoui ◽  
...  

The determinants of normal and leukemic stem cell self-renewal remain poorly characterized. We report that expression of the reactive oxygen species (ROS) scavenger glutathione peroxidase 3 (GPx3) positively correlates with the frequency of leukemia stem cells (LSCs) in Hoxa9+Meis1-induced leukemias. Compared with a leukemia with a low frequency of LSCs, a leukemia with a high frequency of LSCs showed hypomethylation of the Gpx3 promoter region, and expressed high levels of Gpx3 and low levels of ROS. LSCs and normal hematopoietic stem cells (HSCs) engineered to express Gpx3 short hairpin RNA (shRNA) were much less competitive in vivo than control cells. However, progenitor cell proliferation and differentiation was not affected by Gpx3 shRNA. Consistent with this, HSCs overexpressing Gpx3 were significantly more competitive than control cells in long-term repopulation experiments, and overexpression of the self-renewal genes Prdm16 or Hoxb4 boosted Gpx3 expression. In human primary acute myeloid leukemia samples, GPX3 expression level directly correlated with adverse prognostic outcome, revealing a potential novel target for the eradication of LSCs.


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.


2020 ◽  
Author(s):  
Yuncheng Liu ◽  
Feidi Xiao ◽  
Xiang Hu ◽  
Zan Tang ◽  
Zeqin Fu ◽  
...  

Abstract Mesenchymal stem cells (MSC) are a popular candidate in cellular therapy for many diseases. MSCs are well known by their feature of self-renewal and their differentiation potential. NESTIN is a cytoskeletal protein expressed in MSC that functions directly in cell proliferation and differentiation. Here, we demonstrated that adding UltraGRO, a medium supplement, could maintain and partially recover the expression of NESTIN in human umbilical cord derived MSCs (UC-MSCs). Furthermore, the UC-MSCs cultured with UltraGRO showed a better immunomodulation ability in a colitis mouse model compared with those cultured in other types of media. This indicates that the use of novel culture medium benefits the maintenance of NESTIN expression and NESTIN may be one of the vital factors that regulates the performance of MSCs.


2007 ◽  
Vol 19 (1) ◽  
pp. 119
Author(s):  
L. Arregui ◽  
R. Rathi ◽  
W. Zeng ◽  
A. Honaramooz ◽  
M. Gomendio ◽  
...  

Testis tissue grafting presents an option for preservation of genetic material when sperm recovery is not possible. Grafting of testis tissue from sexually immature males to immunodeficient mice results in germ cell differentiation and production of fertilization-competent sperm from different mammalian species (Honaramooz et al. 2002 Nature 418, 778–781). However, the efficiency of testis tissue xenografting from adult donors has not been critically evaluated. Spermatogenesis was arrested at meiosis in grafts from mature horses (Rathi et al. 2006 Reproduction 131, 1091–1098) and hamsters (Schlatt et al. 2002 Reproduction 124, 339–346), and no germ cell differentiation occurred in xenografts of adult human testis tissue (Schlatt et al. 2006 Hum. Reprod. 21, 384–389). The objective of this study was to investigate survival and germ cell differentiation of testis xenografts from sexually mature donors of different species. Small fragments of testis tissue from 10 donor animals of 5 species were grafted under the back skin of immunodeficient, castrated male mice (n = 37, 2–6/donor). Donors were pig (8 months old), goat (18 months old and 4 years old) (n = 2), bull (3 years old), donkey (13 months old), and rhesus monkey (3, 6, 11, and 12 years old). At the time of grafting, donor tissue contained elongated spermatids, albeit to different degrees (>75% of seminiferous tubules in testis tissue from pig, goat, bull, and 6–12-year-old monkeys, and 33 or 66% of tubules in tissue from donkey or 3-year-old monkey, respectively). Grafts were recovered <12 weeks (n = 14 mice), 12–24 weeks (n = 16 mice), and >24 weeks (n = 7 mice) after grafting and classified histologically as completely degenerated (no tubules found), degenerated tubules (only hyalinized seminiferous tubules observed), or according to the most advanced type of germ cell present. Grafts from pig, goat, bull, and 6–12-year-old monkeys contained >60% degenerated tubules or were completely degenerated at all time points analyzed. In contrast, in grafts from the 3-year-old monkey, only 18% of tubules were degenerated, 14% contained Sertoli cells only, 64% contained meiotic, and 4% haploid germ cells at 24 weeks after grafting. Similarly, donkey testis grafts recovered 12–24 weeks after grafting contained <2% degenerated tubules, 46% of tubules had Sertoli cells only, 45% contained meiotic, and 7% haploid germ cells. These results show that survival and differentiation of germ cells in testis grafts from sexually mature mammalian donors is poor. However, better graft survival and maintenance of spermatogenesis occurred in donor tissue from donkey and 3-year-old monkey that were less mature at the time of grafting. Therefore, species and age-related differences appear to exist with regard to germ cell survival and differentiation in xenografts from adult donors. This work was supported by USDA/CSREES 03-35203-13486, NIH/NCRR 5-R01-RR17359-05, the Spanish Ministry of Education, and Science (BES-2004-4112).


2008 ◽  
Vol 20 (1) ◽  
pp. 189
Author(s):  
J. Baldrighi ◽  
W. Averhart ◽  
M. Mello ◽  
J. Ford ◽  
L. Franca ◽  
...  

Currently, swine biotechnologies related to reproduction increase considerably. Investments are made in order to improve the reproductive rates and performance of breeding stock. Understanding the physiology of spermatogenesis will help increase sperm production and improve boar efficiency. Sertoli cells are the only somatic cells present in the seminiferous tubules. Their function is to guarantee proper sperm formation and maturation. Each Sertoli cell is responsible for nursing a finite number of spermatogonia. At puberty, Sertoli cell maturation and lumen formation have occurred within the seminiferous tubules and germ cells have proliferated rapidly followed by the onset of spermatogenesis. At least two hormones are known to play a role in Sertoli cell proliferation and maturation: follicle-stimulating hormone (FSH) and thyroid hormone. FSH secretion has been assumed to be the stimulus for proliferation. The thyroid hormone is responsible for normal postnatal growth and development. Alterations in thyroid activity have frequently been associated with changes in male reproductive functions, since hypothyroidism, induced with 6-N-propyl-2-thiouracil (PTU) soon after birth, is associated with a marked delay in sexual maturation and development. The goal of this study was to report the effect of FSH and PTU on the stages of sperm cell development of young pigs. Six piglets of 1, 7, 14, 25, and 55 days of age were castrated and their testes were sectioned to grafts of 5 mm3. The grafts were then transplanted subcutaneously into the dorsum of 12 castrated nude mice per age group. Two days post-surgery mice were randomly assigned to one of four treatment groups: control, FSH (5 IU rFSH), PTU (0.015% solution), and FSH + PTU. Following 14 days of treatment, testicular tissue pieces were allowed to grow for 2 additional weeks. Tissues were then harvested, immersion-fixed in neutral buffered formalin, and embedded in paraffin. Five-micron-thick sections were stained using hematoxylin and eosin. Slides were evaluated under light microscopy and the oldest germ cell type present in each section was recorded. Germ cell types were recorded as spermatogonium, spermatocyte, early spermatid, and late spermatid. Statistical differences between all groups were detected using paired Student t-tests. There were no differences noted between control groups and those treated with PTU or FSH alone. No effect concerning age of castration on grafts development was observed. There was a slightly significant increase (P = 0.05) in the number of spermatocytes observed in the groups treated with FSH+PTU. These data suggest that there is a potential synergistic effect of FSH and PTU on sperm cell development. Based on these results, further studies need to be performed to completely understand the effect of these two hormones on Sertoli cells.


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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