Analysis of MiRNA-17 and MiRNA-146 Expression During Differentiation of Spermatogonial Stem Like Cells Derived from Mouse Bone Marrow Mesenchymal Stem Cells

In vitro derivation of germ cells from different stem cells sources has been challenging in the treatment of male infertility. MicroRNAs (miRNAs) have an essential role in gene expression at post-transcriptional level. The aim of this research was to find more about miRNA-17 and miRNA-146 expression during differentiation of spermatogonial stem cell like cells (SSC like cells) from mouse bone marrow mesenchymal stem cells (BMSCs) through bone morphogenic protein 4 (BMP4) and retinoic acid (RA) induction. BMSCs were treated with BMP4 to produce primordial germ cell like cells (PGC like cells). The cells were differentiated into SSC like cells by an inducer cocktail including RA, leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF). The PGC like cells and SSC like cells were evaluated for pluripotency (Nanog, Oct-4) and germ cell specific gene (Piwil2, Plzf, Dazl, and Stra8) expression, protein expression (Plzf, Stra8), and miRNA-17 and miRNA-146 mRNA expression. Our results showed that BMP4 lead to Dazl up-regulation and Nanog down-regulation expression in PGC like cells. RA up-regulated Stra8 and Piwil2, and down-regulated Nanog and Oct-4. MiRNA-17 and miRNA-146 expression decreased significantly in SSC like cells after RA treatment. This research indicated the aberrant miRNA-17 and miRNA-146 expression in SSC like cells in comparison with SSCs. Down-regulation of the two miRNAs by using RA in the stimulated undifferentiated state could be probably one of the key factors of SSC like cells arrest.