Expression of vascular endothelial growth factor receptors 1, 2 and 3 in placentas from normal and complicated pregnancies

Extensive angiogenesis and invasion of the maternal decidua by trophoblasts are essential for the development and function of the placenta, Vascular e ndothelial growth factors (VEGF), placenta growth factor (PIGF) and their r eceptors VEGFR-1/Flt-1, VEGFR-2/KDR and VEGFR-3/Flt4 have important roles i n vasculogenesis and angiogenesis. We have studied the localization of thes e proteins by immunohistochemistry and Western blotting in the placenta and of PIGF in maternal serum, and their association with diabetes, pre-eclamp sia, fetal growth restriction (FGR) and fetal alcohol syndrome (FAS). VEGFR -1 and VEGFR-3 were detected mainly in the syncytiotrophoblastic layer wher eas VEGFR-2 was detected in the vascular endothelial cells of the placenta. VECFR-1, but not the other receptors, showed increased expression in place ntal syncytiotrophoblasts from 50% of patients with severe pre-eclampsia an d FGR when compared with normal placentas. PIGF was undetectable in 38 of 4 4 samples of amniotic fluid of mothers with normal and complicated pregnanc ies. However, maternal serum PICF concentrations were significantly lower i n pre-eclamptic patients and in those with FGR when compared to diabetic wo men or healthy controls, These results suggest that low maternal serum PIGF and increased placental expression of its receptor VEGFR-1 are associated with pre-eclampsia and FGR.