Little is known about the negative regulation of angiogenesis in the ovary. Recent evidence has revealed that estradiol 17β and its metabolites may play an important role in this fine tuning1. In a previous work2, we set up an assay to quantify 2-hydroxyestradiol (2-OHE) and 4-hydroxyestradiol (4-OHE) in follicular fuids. In order to get an insight on the angiogenic effect of 4-OHE and 2-OHE, the objective of this research was to study their possible modulatory role on VEGF-induced endothelial cell growth. To this purpose, we set up a reliable bioassay which allows the study of porcine aortic endothelial cells (AOC) growth on a three dimensional fibrin gel matrix3. AOC were cultured on microcarries beads and then pipetted into a solution of fibrinogen and thrombine; cells were then treated with VEGF (100 ng/ml) in the presence or absence of 4-OHE or 2-OHE (1, 10 and 100 ng/ml) and incubated at 37 °C under humidified atmosphere (5% CO2) for 48 h. Endothelial cell proliferation was measured by means of the public domain NIH program Scion Image Beta (Scion Corporation, MA, USA). A significant (P<0.001) inhibition of AOC growth was induced by both catecholestrogens. No differences have been observed among the different concentration tested (P<0.001). These data suggest that 4-OHE and 2-OHE, the endogenous estradiol metabolites present in the ovarian follicle, can potentially act as physiological antiangiogenesis regulators.
This research was supported by a FIL grant.
1. Basini et al. Steroids 2007 72 660665.
2. Basini et al. Reprod Domest Anim 2007 42 211.
3. Basini et al. Biofactors 2007 29 1118.
03 - 07 May 2008
European Society of Endocrinology