Differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells into germ-like cells in vitro

Recent studies have demonstrated that mesenchymal stem cells could differentiate into germ cells under appropriate conditions. We sought to determine whether human umbilical cord Wharton's jelly-derived mesenchymal stem cells (HUMSCs) could form germ cells in vitro. HUMSCs were induced to differentiate into germ cells in all-trans retinoic acid, testosterone and testicular-cell-conditioned medium prepared from newborn male mouse testes. HUMSCs formed "tadpole-like" cells after induction with different reagents and showed both mRNA and protein expression of germ-cell-specific markers Oct4 (POUF5), Ckit, CD49(f) (alpha6), Stella (DDPA3), and Vasa (DDX4). Our results may provide a new route for reproductive therapy involving HUMSCs and a novel in vitro model to investigate the molecular mechanisms that regulate the development of the mammalian germ lineage.