EGFR (Epidermal Growth Factor Receptor) Signaling and the Mitochondria Regulate sFlt-1 (Soluble FMS-Like Tyrosine Kinase-1) Secretion

Preeclampsia is a hypertensive disorder of pregnancy characterized by maternal endothelial dysfunction and end-organ damage. The antiangiogenic factor, sFlt-1 (soluble FMS-like tyrosine kinase-1) has been strongly implicated in the pathogenesis of preeclampsia. sFlt-1 is secreted into the maternal circulation where it antagonizes VEGF (vascular endothelial growth factor) and ultimately disrupts vascular homeostasis. However, the upstream mechanisms regulating release of sFlt-1 are poorly characterized. We investigated the roles of key prosurvival pathways, EGFR (epidermal growth factor receptor) signaling, and the mitochondria, in regulating sFlt-1 production. We initially found that the mRNA and protein of EGFR and downstream adaptor molecules were significantly increased in preeclamptic placental tissue relative to normotensive controls. Inhibiting the EGFR signaling cascade using siRNA (small interfering ribonucleic acid) or small molecule inhibitors significantly reduced sFlt-1 release from primary cy...