Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Tumor suppressor gene Rb is required for self-renewal of spermatogonial stem cells in mice.

ABSTRACT: The retinoblastoma tumor suppressor gene Rb is essential for maintaining the quiescence and for regulating the differentiation of somatic stem cells. Inactivation of Rb in somatic stem cells typically leads to their overexpansion, often followed by increased apoptosis, defective terminal differentiation, and tumor formation. However, Rb's roles in germ-line stem cells have not been explored. We conditionally disrupted the Rb gene in mouse germ cells in vivo and discovered unanticipated consequences for GFRa1-protein-expressing A(single) (GFRa1(+) A(s)) spermatogonia, the major source of male germ-line stem cells. Rb-deficient GFRa1(+) A(s) spermatogonia were present at normal density in testes 5 d after birth, but they lacked the capacity for self-renewal, resulting in germ cell depletion by 2 mo of age. Rb deficiency did not affect the proliferative activity of GFRa1(+) A(s) spermatogonia, but their progeny were exclusively transit-amplifying progenitor spermatogonia and did not include GFRa1(+) A(s) spermatogonia. In addition, Rb deficiency caused prolonged proliferation of progenitor spermatogonia, transiently enlarging this population. Despite these defects, Rb deficiency did not block terminal differentiation into functional sperm; offspring were readily obtained from young males whose germ cell pool was not yet depleted. We conclude that Rb is required for self-renewal of germ-line stem cells, but contrary to its critical roles in somatic stem cells, it is dispensable for their proliferative activity and terminal differentiation. Thus, this study identifies an unexpected function for Rb in maintaining the stem cell pool in the male germ line.

SUBMITTER: Hu YC

PROVIDER: S-EPMC3732951 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Bud31-mediated alternative splicing is required for spermatogonial stem cell self-renewal and differentiation.

Project description:Alternative splicing (AS) is tightly regulated during cell differentiation and development. AS events are prevalent in the testis, but the splicing regulation in spermatogenesis remains unclear. Here we report that the spliceosome component Bud31 plays a crucial role during spermatogenesis in mice. Germ cell-specific knockout of Bud31 led to loss of spermatogonia and to male infertility. We further demonstrate that Bud31 is required for both spermatogonial stem cell pool maintenance and the initiation of spermatogenesis. SMART-seq revealed that deletion of Bud31 in germ cells causes widespread exon-skipping and intron retention. Particularly, we identified Cdk2 as one of the direct splicing targets of Bud31, knockout of Bud31 resulted in retention of the first intron of Cdk2, which led to a decrease in Cdk2 expression. Our findings suggest that Bud31-mediated AS within spermatogonial stem cells regulates the self-renewal and differentiation of male germ cells in mammals.

| S-EPMC9883385 | biostudies-literature

Spermatogonial stem cell self-renewal requires ETV5-mediated downstream activation of Brachyury in mice.

Project description:Insight regarding mechanisms controlling gene expression in the spermatogonial stem cell (SSC) will improve our understanding of the processes regulating spermatogenesis and aid in treating problems associated with male infertility. In the present study, we explored the global gene expression profiles of the glial cell line-derived neurotrophic factor (GDNF)-regulated transcription factors Ets (E-twenty-six) variant gene 5 (Etv5); B-cell chronic lymphocytic leukemia (CLL)/lymphoma 6, member B (Bcl6b); and POU domain, class-3 transcription factor 1 (Pou3f1). We reasoned that these three factors may function as a core set of transcription factors, regulating genes responsible for maintaining the SSC population. Using transient siRNA oligonucleotides to individually target Etv5, Bcl6b, and Pou3f1 within mouse SSC cultures, we examined changes to the global gene expression profiles associated with these transcription factors. Only modest overlaps in the target genes regulated by the three factors were noted, but ETV5 was found to be a critical downstream regulator of GDNF signaling that mediated the expression of several known SSC self-renewal related genes, including Bcl6b and LIM homeobox 1 (Lhx1). Notably, ETV5 was identified as a regulator of Brachyury (T) and CXC chemokine receptor, type 4 (Cxcr4), and we showed that ETV5 binding to the Brachyury (T) gene promoter region is associated with an active state of transcription. Moreover, in vivo transplantation of SSCs following silencing of Brachyury (T) significantly reduced the number of donor cell-derived colonies formed within recipient mouse testes. These results suggest Brachyury is of biological importance and functions as part of GDNF/ETV5 signaling to promote self-renewal of mouse SSCs cultured in vitro.

| S-EPMC3223249 | biostudies-literature

ROS amplification drives mouse spermatogonial stem cell self-renewal.

Project description:Reactive oxygen species (ROS) play critical roles in self-renewal division for various stem cell types. However, it remains unclear how ROS signals are integrated with self-renewal machinery. Here, we report that the MAPK14/MAPK7/BCL6B pathway creates a positive feedback loop to drive spermatogonial stem cell (SSC) self-renewal via ROS amplification. The activation of MAPK14 induced MAPK7 phosphorylation in cultured SSCs, and targeted deletion of Mapk14 or Mapk7 resulted in significant SSC deficiency after spermatogonial transplantation. The activation of this signaling pathway not only induced Nox1 but also increased ROS levels. Chemical screening of MAPK7 targets revealed many ROS-dependent spermatogonial transcription factors, of which BCL6B was found to initiate ROS production by increasing Nox1 expression via ETV5-induced nuclear translocation. Because hydrogen peroxide or Nox1 transfection also induced BCL6B nuclear translocation, our results suggest that BCL6B initiates and amplifies ROS signals to activate ROS-dependent spermatogonial transcription factors by forming a positive feedback loop.

| S-EPMC6448598 | biostudies-literature

Myc/Mycn-mediated glycolysis enhances mouse spermatogonial stem cell self-renewal.

Project description:Myc plays critical roles in the self-renewal division of various stem cell types. In spermatogonial stem cells (SSCs), Myc controls SSC fate decisions because Myc overexpression induces enhanced self-renewal division, while depletion of Max, a Myc-binding partner, leads to meiotic induction. However, the mechanism by which Myc acts on SSC fate is unclear. Here we demonstrate a critical link between Myc/Mycn gene activity and glycolysis in SSC self-renewal. In SSCs, Myc/Mycn are regulated by Foxo1, whose deficiency impairs SSC self-renewal. Myc/Mycn-deficient SSCs not only undergo limited self-renewal division but also display diminished glycolytic activity. While inhibition of glycolysis decreased SSC activity, chemical stimulation of glycolysis or transfection of active Akt1 or Pdpk1 (phosphoinositide-dependent protein kinase 1 ) augmented self-renewal division, and long-term SSC cultures were derived from a nonpermissive strain that showed limited self-renewal division. These results suggested that Myc-mediated glycolysis is an important factor that increases the frequency of SSC self-renewal division.

| S-EPMC5204355 | biostudies-literature

Identifying genes important for spermatogonial stem cell self-renewal and survival.

Project description:Spermatogonial stem cells (SSCs) are the foundation for spermatogenesis and, thus, preservation of a species. Because of stem cell rarity, studying their self-renewal is greatly facilitated by in vitro culture of enriched biologically active cell populations. A recently developed culture method identified glial cell line-derived neurotrophic factor (GDNF) as the essential growth factor that supports in vitro self-renewal of SSCs and results in an increase in their number. This system is a good model to study mechanisms of stem cell self-renewal because of the well defined culture conditions, enriched cell population, and available transplantation assay. By withdrawing and replacing GDNF in culture medium, we identified regulated expression of many genes by using microarray analysis. The expression levels of six of these genes were dramatically decreased by GDNF withdrawal and increased by GDNF replacement. To demonstrate the biological significance of the identified GDNF-regulated genes, we examined the importance of the most responsive of the six, bcl6b, a transcriptional repressor. By using siRNA to reduce transcript levels, Bcl6b was shown to be crucial for SSC maintenance in vitro. Moreover, evaluation of Bcl6b-null male testes revealed degeneration and/or absence of active spermatogenesis in 24 +/- 7% of seminiferous tubules. These data suggest that Bcl6b is an important molecule in SSC self-renewal and validate the biological relevance of the GDNF-regulated genes identified through microarray analysis. In addition, comparison of data generated in this study to other stem cell types suggests that self-renewal in SSCs is regulated by distinctly different molecular mechanisms.

| S-EPMC1480440 | biostudies-literature

MicroRNA-21 regulates the self-renewal of mouse spermatogonial stem cells.

Project description:MicroRNAs (miRs) play a key role in the control of gene expression in a wide array of tissue systems, where their functions include the regulation of self-renewal, cellular differentiation, proliferation, and apoptosis. However, the functional importance of individual miRs in controlling spermatogonial stem cell (SSC) homeostasis has not been investigated. Using high-throughput sequencing, we profiled the expression of miRs in the Thy1(+) testis cell population, which is highly enriched for SSCs, and the Thy1(-) cell population, composed primarily of testis somatic cells. In addition, we profiled the global expression of miRs in cultured germ cells, also enriched for SSCs. Our results demonstrate that miR-21, along with miR-34c, -182, -183, and -146a, are preferentially expressed in the Thy1(+) SSC-enriched population, compared with Thy1(-) somatic cells. Importantly, we demonstrate that transient inhibition of miR-21 in SSC-enriched germ cell cultures increased the number of germ cells undergoing apoptosis and significantly reduced the number of donor-derived colonies of spermatogenesis formed from transplanted treated cells in recipient mouse testes, indicating that miR-21 is important in maintaining the SSC population. Moreover, we show that in SSC-enriched germ cell cultures, miR-21 is regulated by the transcription factor ETV5, known to be critical for SSC self-renewal.

| S-EPMC3150879 | biostudies-literature

Self renewal, expansion, and transfection of rat spermatogonial stem cells in culture.

Project description:The use of a transgenic line of rats that express enhanced GFP (EGFP) exclusively in the germ line has allowed a separation of feeder layers and contaminating testis somatic cells from germ cells and the identification of a set of spermatogonial stem cell marker transcripts. With these molecular markers as a guide, we have now devised culture conditions where rat spermatogonial stem cells renew and proliferate in culture with a doubling time between 3 and 4 days. The marker transcripts increase in relative abundance as a function of time in culture, and the stem cells retain competency to colonize and develop into spermatids after transplantation to the testes of recipient rats. The cells also remain euploid after at least 12 passages. Cell lines could be isolated and cryopreserved and, upon subsequent thawing, continue to self renew. Transfection of the spermatogonial stem cells with a plasmid containing the neomycin phosphotransferase (neo) selectable marker resulted in selection of G418-resistant cell lines that effectively colonize recipient testes, suggesting that gene targeting is now feasible in the rat.

| S-EPMC1283987 | biostudies-literature

Conservation of spermatogonial stem cell self-renewal signaling between mouse and rat.

Project description:Self-renewal of spermatogonial stem cells (SSCs) is the foundation for maintenance of spermatogenesis throughout life in males and for continuation of a species. The molecular mechanism underlying stem cell self-renewal is a fundamental question in stem cell biology. Recently, we identified growth factors necessary for self-renewal of mouse SSCs and established a serum-free culture system for their proliferation in vitro. To determine whether the stimulatory signals for SSC replication are conserved among different species, we extended the culture system to rat SSCs. Initially, a method to assess in vitro expansion of SSCs was developed by using flow cytometric analysis, and, subsequently, we found that a combination of glial cell line-derived neurotrophic factor, soluble glial cell line-derived neurotrophic factor-family receptor alpha-1 and basic fibroblast growth factor supports proliferation of rat SSCs. When cultured with the three factors, stem cells proliferated continuously for >7 months, and transplantation of the cultured SSCs to recipient rats generated donor stem cell-derived progeny, demonstrating that the cultured stem cells are normal. The growth factor requirement for replication of rat SSCs is identical to that of mouse; therefore, the signaling factors for SSC self-renewal are conserved in these two species. Because SSCs from many mammals, including human, can replicate in mouse seminiferous tubules after transplantation, the growth factors required for SSC self-renewal may be conserved among many different species. Furthermore, development of a long-term culture system for rat SSCs has established a foundation for germ-line modification of the rat by gene targeting technology.

| S-EPMC1242328 | biostudies-literature

MicroRNA-224 regulates self-renewal of mouse spermatogonial stem cells via targeting DMRT1.

Project description:MicroRNAs (miRs) play a key role in the control of gene expression in a wide array of tissue systems, where their functions include the regulation of self-renewal, cellular differentiation, proliferation and apoptosis. However, the function and mechanisms of individual miRs in regulating spermatogonial stem cell (SSC) homeostasis remain unclear. In the present study, we report for the first time that miR-224 is highly expressed in mouse SSCs. Functional assays using miRNA mimics and inhibitors reveal that miR-224 is essential for differentiation of SSCs. Mechanistically, miR-224 promotes differentiation of SSCs via targeting doublesex and Mab-3-related transcription factor 1 (DMRT1). Moreover, WNT/β-catenin signalling pathway is involved in miR-224-mediated regulation of SSCs self-renewal. We further demonstrate that miR-224 overexpression increases the expression of GFRα1 and PLZF, accompanied by the down-regulation of DMRT1 in mouse testes. Our findings provide novel insights into molecular mechanisms regulating differentiation of SSCs and may have important implications for regulating male reproduction.

| S-EPMC4956939 | biostudies-literature

Growth factors essential for self-renewal and expansion of mouse spermatogonial stem cells.

Project description:Spermatogonial stem cells (SSCs) self-renew and produce large numbers of committed progenitors that are destined to differentiate into spermatozoa throughout life. However, the growth factors essential for self-renewal of SSCs remain unclear. In this study, a serum-free culture system and a transplantation assay for SSCs were used to identify exogenous soluble factors that promote proliferation of SSCs. Mouse pup testis cells were enriched for SSCs by selection with an anti-Thy-1 antibody and cultured on STO (SIM mouse embryo-derived thioguanine and ouabain resistant) feeders in a serum-free defined medium. In the presence of glial cell line-derived neurotrophic factor (GDNF), SSCs from DBA/2J strain mice formed densely packed clumps of cells and continuously proliferated. However, other strains of mice required the addition of soluble GDNF-family receptor alpha-1 and basic fibroblast growth factor to support replication. The functional transplantation assay proved that the clump-forming cells are indeed SSCs. Thus, GDNF-induced cell signaling plays a central role in SSC self-renewal. The number of SSCs in culture doubled every 5.6 days, and the clump-forming cells strongly expressed Oct-4. Under these conditions, SSCs proliferated over 6 months, reconstituted long-term spermatogenesis after transplantation into recipient testes, and restored fertility to infertile recipients. The identification of exogenous factors that allow continuous proliferation of SSCs in vitro establishes the foundation to study the basic biology of SSCs and makes possible germ-line modification by sophisticated technologies. Moreover, the ability to recover, culture indefinitely, and transplant SSCs will make the germ-line of individual males available for periods extending beyond a normal lifetime.

| S-EPMC534530 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data