ESTROGENS, PROGESTERONE AND INTEGRIN-FIBRONECTIN INTERACTION DURING PORCINE PLACENTATION

VELEZ, CAROLINA; WILLIAMSON, DELIA; RIESCO, OSCAR; MARTÍN, PAMELA; GARCÍA, MÓNICA; YAFUL, GRACIELA; KONCURAT, MIRTA

Mar del Plata

Congreso; VI Latin American Symposium on Maternal-Fetal Interaction and Placenta and V Latin American Symposium on Reproductive Immunology Meeting 2015; 2015

SLIMP-LASRI

Objective: The aim of this study was to correlate estrogen (E2) and progesterone(P4) concentrations with integrin avb3 expression and itsligand, fibronectin (FN) in the fetal-maternal interface during porcineplacentation.Methods: Placental samples from crossbred females (n ¼ 35) of ± 17, 35,60, 70, 80 and 114 days of gestation (dg) and empty uterus (n¼5) wereused. E2 and P4 levels were determined by chemiluminescence (DiagnosticProducts Corporation, USA). The presence of fibronectin (Abcam, UKand Santa Cruz Biotechnology, USA) and avb3 (Chemicom, USA) wasdetermined by indirect immunoperoxidase using monoclonal primaryantibodies.Results: Increased FN expression was found in trophoblasts at 17, 35 and60 dg, decreasing immunostaining as of 70 dg. A similar pattern of avb3expression was obtained. Staining of both molecules on endometrialluminal epitheliumwas milder. E2 levels showed a peak at 35 and 60 dg infetal placental extracts (HoPF) (2058 pg/ml and 1898 pg/ml, respectively),diminishing and then, increasing significantly from 80 dg (6926 pg/ml). E2levels determined in serum and maternal placental extracts were lowerbut had the same secretion pattern. The highest P4 concentrationwas at 70dg in HoPF (83.25 ng/ml) compared to HoPM (2.66 ng/ml) and serum(22.6ng/ml). Fibronectin and integrin avb3 were strongly expressed in trophoblastsat early and middle gestation, a stage at which E2 had a slightpeak, together with high P4 concentrations in both serum level and inmaternal and fetal extracts. As of 70 dg a significant E2 increase and P4reduction coincided with the decreased avb3 expression and FN introphoblast and endometrial luminal epithelial cells.Conclusion: The results suggest that progesterone would regulate integrinavb3 expression and fibronectin. We postulate that at the end of pregnancy,estrogen high levels would inhibit integrin expression and fibronectinin endometrial epithelium in preparation for placental expulsion.