LAUSR

Significance During pregnancy, extravillous trophoblasts (EVTs) detach from anchoring sites of the placenta, differentiate, and invade the maternal uterus to remodel its vasculature. Failures in this program contribute to placentation defects observed in gestational disorders such as spontaneous pregnancy loss, early-onset preeclampsia, and fetal growth restriction. However, critical regulators and signaling pathways controlling EVT development have been poorly elucidated. In the present study, we demonstrate that transforming growth factor-β (TGF-β) signaling plays a pivotal role in the differentiation program of EVTs. In vitro, loss of Wingless signaling was sufficient for EVT formation in self-renewing trophoblast models, whereas subsequent activation of TGF-β signaling accomplished differentiation into trophoblasts that display some features of in vivo EVTs.