GDF-11 stimulates human extravillous trophoblast cell invasion by upregulating ANGPTL4 expression

Proper regulation of extravillous trophoblast (EVT) cell invasion is critical for normal placental development and function. Growth differentiation factor 11 (GDF-11), a member of the transforming growth factor-β (TGF-β) superfamily, has been shown to promote EVT cell invasion, yet the underlying molecular mechanisms remain largely unclear. In this study, RNA sequencing identified angiopoietin-like 4 (ANGPTL4), a multifunctional secreted protein, as a novel downstream target of GDF-11. In vitro experiments demonstrated that GDF-11 significantly upregulated ANGPTL4 expression in both HTR-8/SVneo cells and primary human EVT cells. Mechanistically, we found that the type I TGF-β receptors ALK4 and ALK5 were essential for mediating the stimulatory effect of GDF-11 on ANGPTL4 expression. Further analysis revealed that SMAD3, but not SMAD2, was the key transcription factor involved in this process. Using both loss- and gain-of-function approaches, we demonstrated that ANGPTL4 was required for GDF-11-induced EVT cell invasion. Importantly, serum levels of GDF-11 were markedly reduced in patients with preeclampsia (PE), a pregnancy disorder associated with shallow trophoblast invasion and poor placentation. Together, our findings uncover a previously unrecognized GDF-11-ANGPTL4 signaling axis that regulates EVT cell invasion and provides new insight into the pathophysiology of PE.