A Tissue-based Proteomic Study of VEGFR2 in Human Term Placentas Revealed its Association with Pyruvate Dehydrogenase and MDMX

VEGFR2 is the main regulator of placental angiogenesis and at term is localized in endothelial cells (EC) of the villous vasculature. VEGFR2 immunoprecipitation (IP) of membrane proteins, extracted from the fetal compartment, isolated 30 proteins that were identified by proteomic analysis. Among them are pyruvate dehydrogenase (PD) component-E2 (DLAT), heterogeneous nuclear ribonucleoproteins, annexins, MDMX and titin. Some of these interactions would involve the “nuclear” VEGFR2 since VEGFR2 and PD translocate to the nucleus. Ingenuity pathway analysis of VEGFR2-IP predicted association of 11 proteins, not MDMX or titin, with tretinoin-mediated signaling (overlap p-value 8X10-7) potentially expanding with the retinoid family the list of proteins and mechanism of the VEGFR2 signaling pathway.