Osteogenic differentiation of human induced pluripotent stem cell in the presence of testosterone and 17 β-estradiol in vitro.

Recently, numerous scientific approaches have been explored to treat various diseases using stem cells. In 2006, induced pluripotent stem cell (iPSC) were introduced by Takahashi and Yamanaka and showed the potential of self-renewing and differentiation into all types of targeted cells in vitro. In this investigation, we studied the effect of testosterone (T) individually or in the presence of 17 β-estradiol (E2) on osteogenic differentiation of human iPSC (hiPSC) during 2 wk. The optimal concentrations of sex steroid hormones were examined by MTT assay and acridine orange (AO) staining. The impact of E2 and T either individually or together as a combination was examined by ALP activity; the content of total mineral calcium, by von Kossa and alizarin red staining. Additionally, the expression rate of osteogenic specific markers was studied via real-time RT-PCR and immunocytochemistry analyses at day 14 of differentiation. The obtained results illustrated that the differentiation medium supplemented with T-E2 increased not only the ALP enzyme activity and the content of calcium but also the osteogenic-related gene and protein expressions on the 14th day. Furthermore, the results were confirmed by mineralized matrix staining. In conclusion, these data suggest that T could be used as an effective factor for osteogenic induction of hiPSCs combined with the E2 in bone regeneration.