Figure 5

Excess sFlt-1 inhibits VEGF receptor phosphorylation at tyrosine 951. (a) Nitric oxide (NO) release from HUVEC overexpressing chimeric EGF receptor/VEGFR-2 constructs (EGDR) and EGDR with a mutated Y951 (Y951F), following stimulation with EGF (10 ng/ml) for one hour. NO was measured in cell supernatants using a Sievers chemiluminescent NO analyzer and background subtracted. (b) Western blot showing VEGFR-2 and VEGF-2 phosphorylation at tyrosine 951 (p-VEGFR-2 (Y951)) in HUVEC infected with an adenovirus encoding sFlt-1 (sFlt1) or control virus (CMV). β-actin was used as a loading control. (c) Representative immunohistochemical staining for p-VEGFR-2 (Y951) in gestationally-matched normal (pre-term) and preeclamptic (PE) placenta. Data are expressed as mean (± SEM) or representative of three or more independent experiments performed in triplicate.