Glucocorticoid receptor characterization and dexamethasone leptin regulation in placental cells

ANA MEZA; JAIME, MARIANA; CASALE, ROBERTO; VARONE CECILIA; ALEJANDRA ERLEJMAN; MALENA SCHANTON

virtual

Congreso; LXV Congreso de la Sociedad Argentina de Investigación Clínica SAIC; 2020

Sociedad Argenitna de Investigación Clínica

Leptin is a key hormone in placental physiology. It regulates trophoblast survival and fetal maternal tolerance by the induction of HLA-G in placental cells. The expression of leptin in trophoblastic cells is regulated by different endogenous signals. Previous results from our lab demonstrated that estradiol (E2) regulates leptin expression. In this study we aimed to characterize glucocorticoid receptor (GR) and analyze the effect of the synthetic glucocorticoid dexamethasone (DEX) on leptin expression in human placental cells. BeWo cells cultured under standard conditions, and human placental explants were used as well. Western blot immunofluorescence and transient transfection analysis were carried out. We analyze (GR) expression in placental explants. Two isoforms of 67 and 56 KDa were characterized and the smaller one was increased after E2 treatment. Neither of them was induced by 100 nM DEX. Besides the incubation with 100 nM DEX significantly diminished leptin expression regardless the presence of E2. Endogenous GR was not able to be detected in BeWo cells. However, overexpression of a recombinant GR-GFP protein in BeWo cells localized in the nucleus and activated MMTV promoter dependent luc transcription after DEX stimulation. These results demonstrated that GR pathway is active in these cells.In conclusion GR protein is expressed in placental cells as 67 and 56 KDa isoforms and probably mediates the regulation of leptin expression by DEX.