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

Department of Animal Biology, School of Veterinary Medicine, and Penn Bioinformatics Core, University of Pennsylvania, Philadelphia, PA 19104, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 08/2011; 108(31):12740-5. DOI: 10.1073/pnas.1109987108
Source: PubMed

ABSTRACT 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.

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Available from: Shaun Goodyear, Aug 13, 2015
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    • "Several studies have found that some miRNAs participate in spermatogonia self-renewal and spermatogenesis, including miR-221, miR-21, the miR-449 cluster and miR-34b/c. miR-221 plays a crucial role in maintaining the undifferentiated state of mammalian spermatogonia through repression of KIT expression [Yang et al., 2013]; miR-21 is important in maintaining the spermatogonia population and for spermatogonia self-renewal [Niu et al., 2011]. miR-34c regulates the differentiation of mouse embryonic stem cells into male germ-like cells through RARg and promotes SSC differentiation by targeting Nanos2 [Zhang et al., 2012; Yu et al., 2014]. "
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    ABSTRACT: miRNAs, a type of small RNA, play critical roles in mammalian spermatogenesis. Spermatogonia are the foundation of spermatogenesis and are valuable for the study of spermatogenesis. However, the expression profiling of the miRNAs in spermatogonia of dairy goats remains unclear. CD49f has been one of the surface markers used for spermatogonia enrichment by magnetic activated cell sorting (MACS). Therefore, we used a CD49f microbead antibody to purify CD49f-positive and -negative cells of dairy goat testicular cells by MACS and then analysed the miRNA expression in these cells in depth using Illumina sequencing technology. The results of miRNA expression profiling in purified CD49f-positive and -negative testicular cells showed that 933 miRNAs were upregulated in CD49f-positive cells and 916 miRNAs were upregulated in CD49f-negative cells with a twofold increase, respectively; several miRNAs and marker genes specific for spermatogonial stem cells (SSCs) in testis had a higher expression level in CD49f-positive testicular cells, including miR-221, miR-23a, miR-29b, miR-24, miR-29a, miR-199b, miR-199a, miR-27a, and miR-21 and CD90, Gfra1, and Plzf. The bioinformatics analysis of differently expressed miRNAs indicated that the target genes of these miRNAs in CD49f-positive cells were involved in cell-cycle biological processes and the cell-cycle KEGG pathway. In conclusion, our comparative miRNAome data provide useful miRNA profiling data of dairy goat spermatogonia cells and suggest that CD49f could be used to enrich dairy goat spermatogonia-like cells, including SSCs. © 2014 Wiley Periodicals, Inc.
    Journal of Cellular Biochemistry 10/2014; 115(10). DOI:10.1002/jcb.24835 · 3.37 Impact Factor
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    • "For instance, miR-34C is expressed specifically in mouse pachytene spermatocytes and in round spermatids and might play a role in regulating germ cell development [25]. miR-21 is highly expressed in mouse SSC populations and is important for self-renewal or homeostasis of SSCs [26]. Although SSCs are considered to be readily reprogrammed into gPSCs, the underlying mechanisms are poorly understood. "
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    ABSTRACT: Spermatogonial stem cells (SSCs) play fundamental roles in spermatogenesis. Although a handful of genes have been discovered as key regulators of SSC self-renewal and differentiation, the regulatory network responsible for SSC function remains unclear. In particular, small RNA signatures during mouse spermatogenesis are not yet systematically investigated. Here, using next generation sequencing, we compared small RNA signatures of in vitro expanded SSCs, testis-derived somatic cells (Sertoli cells), developing germ cells, mouse embryonic stem cells (ESCs), and mouse mesenchymal stem cells among mouse embryonic stem cells (ESCs) to address small RNA transition during mouse spermatogenesis. The results manifest that small RNA transition during mouse spermatogenesis displays overall declined expression profiles of miRNAs and endo-siRNAs, in parallel with elevated expression profiles of piRNAs, resulting in the normal biogenesis of sperms. Meanwhile, several novel miRNAs were preferentially expressed in mouse SSCs, and further investigation of their functional annotation will allow insights into the mechanisms involved in the regulation of SSC activities. We also demonstrated the similarity of miRNA signatures between SSCs and ESCs, thereby providing a new clue to understanding the molecular basis underlying the easy conversion of SSCs to ESCs.
    BioMed Research International 07/2014; 2014. DOI:10.1155/2014/154251 · 2.71 Impact Factor
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    • "High-throughput sequencing identified miR-21, along with miR-34c, -182, -183, and -146a, as being preferentially expressed spermatogonial stem cell (SSC)enriched population. The transient inhibition of miR-21 in SSCenriched germ cell cultures increased the number of germ cells undergoing apoptosis and reduced the SSC potency, indicating that miR-21 is important for maintaining the SSC population (Niu et al., 2011). miR-34c is highly expressed in spermatocytes and round spermatids (Romero et al., 2011; Bouhallier et al., 2010; Liang et al., 2012). "
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    ABSTRACT: Spermatogenesis is characterized by meiotic divisions and major morphological changes to produce spermatozoa that are capable of independent movement and fertilization of an egg. Male germ cell differentiation is governed by orchestrated, phase-specific gene expression patterns that are tightly controlled at transcriptional and post-transcriptional level. Post-transcriptional regulation of protein-coding mRNAs becomes prominent during the late steps of spermatogenesis when the compacting sperm nucleus becomes transcriptionally inhibited. Small non-coding RNAs are important regulators of gene expression that mainly function post-transcriptionally to control the properties of their target mRNAs. Male germ cells express several classes of small RNAs, including Dicer-dependent microRNAs (miRNAs) and endogenous small interfering RNAs (endo-siRNAs), as well as Dicer-independent piwi-interacting RNAs (piRNAs). Increasing evidence supports the essential role of small RNA-mediated RNA regulation in normal spermatogenesis and male fertility.
    Molecular and Cellular Endocrinology 04/2013; 382(1). DOI:10.1016/j.mce.2013.04.015 · 4.24 Impact Factor
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