Differentiation of human menstrual blood-derived endometrial mesenchymal stem cells into oocyte-like cells.

Human endometrial mesenchymal stem cells (EnSCs) derived from menstrual blood are a unique stem cell source. Evidence suggests that EnSCs exhibit a multi-lineage potential and have attracted extensive attention in regenerative medicine. However, the potential of EnSCs to differentiate into germline cells in vitro remains unclear. In this study, EnSCs were induced to differentiate into germ cells in a differentiation medium supplemented with 20% human follicular fluid. Our results demonstrated that EnSCs derived from human menstrual blood form oocyte-like cells and express germ cell markers. The induced cell aggregates contained not only oocyte-like structures but also cells expressing follicle stimulating hormone receptor and luteotropic hormone receptor, and produced estrogen and progesterone regulated by gonodatropin, suggesting that granulosa-like and theca-like cells were also induced. We further found that granulosa cells promote the development of oocyte-like cells and activate the induction of blastocyst-like structures derived from EnSCs. In conclusion, EnSCs may potentially represent an in vitro system for the investigation of human folliculogenesis.