Wnt and Nodal signaling simultaneously induces definitive endoderm differentiation of mouse embryonic stem cells.

Induced differentiation of definitive endoderm (DE) from embryonic stem cells (ESCs) has been the recent focus of studies investigating regeneration and transplantation of organs of the digestive system. Poor cell survival is the most important challenge to DE differentiation from ESCs. This study aimed to optimize culture conditions to promote the differentiation of mouse ESCs into DE, and to investigate the roles of the Wnt and Nodal signaling pathways in the DE differentiation. The mouse ESCs were treated with or without leukemia inhibitory factor, Wnt3a and Activin A alone or together, and examined the DE differentiation by the DE marker CXCR4 and the ESC marker Oct4. The result showed the optimal induction of differentiation was achieved in cells simultaneously treated with Wnt3a and Activin A. Induction of CXCR4 was also earlier when there was simultaneous activation of Wnt and Nodal signaling compared to the groups treated with only Wnt3a or Activin A alone. These findings provide the basis for the induced differentiation of ESCs for the generation of functional, mature cells of gastrointestinal lineage, which can be potentially used for cell replacement therapy, disease modeling, as well as drug discovery studies.