Growth differentiation factor-11 stimulates human extravillous trophoblast cell invasion by upregulating...

Inadequate extravillous trophoblast (EVT) invasion contributes to several pregnancy-related disorders. Growth differentiation factor-11 (GDF-11), a member of the transforming growth factor-β (TGF-β) superfamily, has recently been identified as a positive regulator of EVT invasiveness. N-cadherin, a calcium-dependent cell-cell adhesion molecule, is essential for adherens junction integrity and plays a critical role in EVT motility and invasion. However, whether GDF-11 regulates N-cadherin expression in human EVT cells remains unknown.

The immortalized EVT cell line HTR-8/SVneo and primary human EVT cells were used as in vitro models. N-cadherin expression following GDF-11 treatment was analyzed by RT-qPCR and Western blotting. The involvement of specific signaling pathways was examined using pharmacological inhibitors and siRNA-mediated gene silencing. Cell invasiveness was assessed using Matrigel-coated transwell invasion assays.

GDF-11 treatment upregulated N-cadherin expression in both the immortalized EVT cell line HTR-8/SVneo and primary human EVT cells. Pharmacological inhibition and siRNA knockdown experiments revealed that ALK4 and ALK5 were required for GDF-11-induced N-cadherin expression. Mechanistically, GDF-11 activated both SMAD2 and SMAD3 signaling, but only SMAD3 was necessary for N-cadherin upregulation. GDF-11 also induced the epithelial-mesenchymal transition (EMT)-associated transcription factors Snail and Slug; however, only Slug mediated its stimulatory effect on N-cadherin. Functionally, N-cadherin depletion suppressed both basal and GDF-11-stimulated EVT cell invasion.

These findings identify N-cadherin as a critical downstream effector of GDF-11 signaling, providing mechanistic insight into the role of GDF-11 in placental development and suggesting its potential involvement in pregnancy disorders characterized by impaired trophoblast invasion.