Crosstalk between ERalpha and NFkB transcription factors on E2 induced leptin expression in placental cells.

ANTONIO PÉREZ PÉREZ; VÍCTOR SÁNCHEZ MARGALET; MARIA FERNANDA CAMISAY; CASALE, ROBERTO; MALENA SCHANTON; BERNARDO MASKIN; CECILIA L. VARONE

Congreso; International Federation of Placenta Associations IFPA; 2019

ObjectivesLeptin is a key hormone in placental physiology. It regulates trophoblast proliferation, inhibits apoptosis, stimulates protein synthesis, and regulates fetal growth and development. It plays an important role in reproduction mainly because it has been suggested to have function in the placenta during the gestation, where leptin and leptin receptors expression were detected. Previous results from our lab demonstrated that estradiol (E2) regulates leptin expression involving genomic and non-genomic effects. In the present work, we analysed the crosstalk between estrogen receptor alpha (ER and NFB transcription factors on E2 induced leptin expression in human trophoblast cells. Methods:BeWo cells, cultured and human term placental explants were used. Western blot, immunocytochemistry, co-immunoprecipitation and transfection assays were carried out. Ethical review committee at the Alejandro Posadas National Hospital approved all procedures.Results:We found that E2 treatment significantly enhanced the NFB member p65 expression both in BeWo cells and human term placental explants. Moreover E2 increased IKBphosphorylation and NFB transcriptional activity determined by reporter analysis. We also evaluated the localization of ER and p65 NFB subunit in BeWo cells by immunofluorescence assay. We found that both proteins are located in the cytoplasm and migrate to the nucleus when they are overexpressed. Besides ER and p65 form a complex determined by co-immunoprecipitation, as previously seen. These findings suggest that the transcription factor NFB, might be affecting estradiol leptin induction. Finally through transient transfection analysis we observed that the overexpression of RelA (p65) and HEGO (ERincreases basal transcriptional activity of leptin promoter. Conclusion:These results suggest that leptin expression is tightly regulated and help to comprehend the mechanisms where E2 regulated leptin expression possibly involving the cooperation between ER and NFB transcription factors.