miR-106b enhances human mesenchymal stem cell differentiation to spermatogonial stem cells under germ cell profile genes involved in TGF-b signaling pathways.

Mesenchymal stem cells can be differentiated into tissue-specific cells. MicroRNAs (miRNAs) regulate the translation of mRNAs involved in the growth and development of a variety of cells, including primordial germ cells (PGCs). This study evaluated male germ cell differentiation from human MSCs by miR-106b. The MSCs were obtained from human adipose tissue. The differentiation of MSCs into PGCs was accomplished by transfection of a lentiviral vector expressing miR-106b. MSCs were treated with bone morphogenic factor 4 as a control and also as a putative inducer of PGC differentiation. PGC was differentiated into spermatogonial-like cells by retinoic acid. Moreover, Dazl, Plzf, Stra8, Gfra, and Thy1 gene expressions were investigated using real-time PCR. Our results showed that Dazl, Plzf, and Stra8 genes that were treated with BMP4 and miR-106b did not show any significant difference, meaning that miR-106b, like BMP4, is able to differentiate PGC cells from MSCs. In spermatogonial-like cells, Thy1 was significantly unregulated in both the miR-106b and BMP4 groups. Our findings showed that miR-106b regulates the differentiation of MSCs into PGCs. miR-106b influences on the expression of Dazl, Plzf, and Stra8 genes in PGC and Gfra, Stra8, and Thy1 genes.