Progesterone (PR) and Estrogen (ER) receptors function in decidualization: the role of ERK activation

SARAGÜETA, PATRICIA

Fos de Iguazú

Congreso; V SLIMP-IV LASRI; 2013

SLIMP

Progesterone (PR) and Estrogen (ER) receptors function in decidualization: the role of ERK activation. AC Mestre-Citrinovitz1, G Vallejo1, V Kleff 3, E Winterhager2,3, P Saragüeta1 1 IByME ? CONICET 2 Institut für Molekularbiologie - Universität Duisburg-Essen 3 Institut für Anatomie - Universität Duisburg-Essen Background: Although decidua is critical in implantation, the hormonal regulated pathway of decidualization is still elusive. Here we describe progesterone (PR) and estrogen receptors (ER) functions in in-vivo endometrial differentiation and propose a new role for ERK activation. Methods: We injected pregnant rats with oil, PR (ONA) and ER (ICI) antagonists, and their combination at 5 and 6dpc, and analyzed morphology, phERK, desmin, cyclin D3 and PCNA expression on 7dpc implantation sites. Results: The early ONA treatment completely prevented decidua development. The combination with ICI rescued reabsorption, increased phERK levels and decreased differentiation markers desmin and cyclinD3. As compared with oil injected uteri, the treatment with ICI alone did not change morphology or these proteins expression. Conclusions: We have shown that the balance of PR and ER is crucial for decidualization and that ERK is strongly activated when PR and ER are inactivated, suggesting a compensation role for this kinase. Key words: steroid receptors, MAPK, decidualization.