miR‐34c Enhances Mouse Spermatogonial Stem Cells Differentiation by Targeting Nanos2

Abstract

miRNAs are expressed in many mammalian cells, acting specific roles in regulating gene expression or mediating special mRNAs cleavage by targeting their 3'-untranslated region (3'UTR). Some miRNAs are essential and important for animal development. However, it is still unclear what the relationship is between miR-34c and mammalian spermatogonial stem cells (SSCs). We found that a conserved microRNA-34c through its target-Nanos2, regulating SSCs' differentiation in mouse. Immunohistochemistry analysis of Nanos2 and miR-34c FISH results revealed the opposite expression trends between them. Seven bioinformatics websites and programs predicted that miR-34c has interaction sites in Nanos2's 3'UTR. Dual-luciferase reporter vector and mutated dual-luciferase reporter vector analysis validated that they are interacted. After transfection miR-34c mimics into mouse SSCs, or miR-34c lentiviral vector in vitro co-cultivation with seminiferous tubules, and Western blot analysis demonstrated that miR-34c over-expression could suppress Nanos2 expression in post-transcription level. Our experiments identified that miR-34c may promote meiosis process by interacting with Nanos2 leading up-regulation of Stra8 in mouse spermatogonial stem cells.

Mammalian gonocyte and spermatogonia differentiation: recent advances and remaining challenges

“…These data suggested that miR-34 might have an opposite role to miR-21 by promoting differentiation rather than self-renewal. Indeed, the over-expression of miR-34C in mouse PND6 undifferentiated spermatogonia was found to decrease the expression of NANOS2, leading to the upregulation of NANOS3 and STRA8, markers of spermatogonial differentiation, and premeiosis transition, and that of the meiotic marker SCP3 (Yu et al 2014). These results suggest that spermatogonial differentiation requires not only the induction of differentiation factors, but also the removal of functional brakes such as NANOS2, probably responsible for preventing premature differentiation.…”

MicroRNAs and DNA methylation as epigenetic regulators of mitosis, meiosis and spermiogenesis

“…Meanwhile, miR-34c, miR-182, miR-183 and miR-146a have been shown to be preferentially expressed in the SSC (Thy1 C )-enriched population R26 C Yao, Y Liu and others (Niu et al 2011), reflecting potential roles of these miRNAs in mediating self-renewal and maintenance of mouse SSCs. On the other hand, miR-34c has been demonstrated to be involved in the differentiation of mouse SSCs via targeting Nanos2 (Yu et al 2014). Taken together, miR-34 seems to be associated with both division and differentiation of SSCs through targeting different genes.…”

Epigenetic factors in the regulation of prospermatogonia and spermatogonial stem cells

“…C cultured cells, suggesting that miR-34c promotes differentiation in SSC/ SPCs (Yu et al 2014). In addition to miR-34c and miR146, which play roles in differentiation modulation, RA can up-regulate miR-let7s expression through LIN28 inhibition, implicating RA-induced miRNAs in spermatogonial differentiation (Tong et al 2011).…”

“…Several miRNAs are responsible for mouse SSC/SPC maintenance and differentiation, including miR-21, miR-17-92, miR-106b-25, miR221/222, miR-34c, miR-146, miR-let7s, miR-20 and miR-106a (Niu et al 2011, Tong et al 2011, He et al 2013, Huszar & Payne 2013, Yang et al 2013, Chakraborty et al 2014, Wu et al 2014, Yu et al 2014. Compared with THY1 K spermatogonia, miR-21 is highly expressed in THY1 C SSC/SPCs and is regulated by ETV5 in THY1…”