Background: The aim of this study was to clarify changes in the expression of vascular endothelial growth factor (VEGF) during decidualization by endometrial stromal cells (ESCs) in vitro.
Methods: ESCs were separated by enzymic digestion and filtration, and were cultured with RPMI 1640 in 10% fetal calf serum (FCS) and treated with medroxyprogesterone acetate (MPA) and dibutyryl-cyclic adenosine monophosphate (db-cAMP) to induce decidualization in vitro. The levels of prolactin (PRL) in the culture media were measured by enzyme immunoassay (EIA) and the levels of VEGF were measured by enzyme-linked immunosorbent assay (ELISA). The expression of VEGF mRNA by ESCs and decidualized cells was analyzed by Northern blot analysis.
Results: In treated cells, PRL production was significantly increased due to treatment with both db-cAMP (0.5 mmol/L) and MPA (100 nmol/L). VEGF mRNA expression was detected without any stimulation by ESCs. VEGF production was also significantly greater in cells treated with db-cAMP (0.5 mmol/L) and MPA (1 nmol/L or 100 nmol/L) than in control cells. VEGF mRNA was also increased in association with decidualization in vitro.
Conclusions: VEGF production increased in association with decidualization in this in vitro study. Decidualization of ESCs may play a role in the induction of growth in the human fetus and/or placentation. The mechanism involved may include influencing the production of angiogenic growth factors such as VEGF.