Mir-106b Cluster Regulates Primordial Germ Cells Differentiation from Human Mesenchymal Stem Cells

Objective Numerous evidence indicates that microRNAs (miRNAs) are critical regulators in the spermatogenesisprocess. The aim of this study was to investigate Mir-106b cluster regulates primordial germ cells (PGCs) differentiationfrom human mesenchymal stem cells (MSCs). Materials and Methods In this experimental study, samples containing male adipose (n: 9 samples- age: 25-40 years)were obtained from cosmetic surgeries performed for the liposuction in Imam Khomeini Hospital. The differentiationof MSCs into PGCs was accomplished by transfection of a lentivector expressing miR-106b . The transfection of miR-106b was also confirmed by the detection of a clear green fluorescent protein (GFP) signal in MSCs. MSCs weretreated with bone morphogenic factor 4 (BMP4) protein, as a putative inducer of PGCs differentiation, to induce thedifferentiation of MSCs into PGCs (positive control). After 4 days of transfection, the expression of miR-106b , STELLA,and FRAGILIS genes was evaluated by real-time polymerase chain reaction (PCR). Also, the levels of thymocytedifferentiation antigen 1 (Thy1) protein was assessed by the western blot analysis. The cell surface expression of CD90was also determined by immunocytochemistry method. The cytotoxicity of miR-106b was examined in MSCs after 24,48, and 72 hours using the MTT assay. Results MSCs treated with BMP4 or transfected by miR-106b were successfully differentiated into PGCs. The resultsof this study also showed that the expression of miR-106b was significantly increased after 48 hours from transfection.Also, we showed STELLA, FARGILIS , as well as the protein expression of Thy1, was significantly higher in MSCstransfected by lentivector expressing miR-106b in comparison with MSCs treated with BMP4 (P≤0.05). MTT assayshowed miR-106b was no toxic during 72 hours in 1 µg/ml dose, that this amount could elevated germ cells markersignificantly higher than other experimental groups (P≤0.05). Conclusion According to this findings, it appears that miR-106b plays an essential role in the differentiation of MSCsinto PGCs.