Glucocorticoid receptor characterization and dexamethasone leptin regulation in placental cells

MEZA A ; JAIME M; CASALE R; VARONE C; ERLEJMAN AG; SCHANTON M

Virtual

Congreso; LXV Reunión anual de la Sociedad Argentina de Investigación Clínica (SAIC) en el marco de la Reunión Conjunta de Sociedades de Biociencias; 2020

Sociedad Argenitna de Investigación Clínica

Leptin is a key hormone in placental physiology. It regulates trophoblastsurvival and fetal maternal tolerance by the induction of HLA-Gin placental cells. The expression of leptin in trophoblastic cells isregulated by different endogenous signals. Previous results from ourlab demonstrated that estradiol (E2) regulates leptin expression. Inthis study we aimed to characterize glucocorticoid receptor (GR) andanalyze the effect of the synthetic glucocorticoid dexamethasone(DEX) on leptin expression in human placental cells. BeWo cellscultured under standard conditions, and human placental explantswere used as well. Western blot immunofluorescence and transienttransfection analysis were carried out. We analyze (GR) expressionin placental explants. Two isoforms of 67 and 56 KDa were characterizedand the smaller one was increased after E2 treatment.Neither of them was induced by 100 nM DEX. Besides the incubationwith 100 nM DEX significantly diminished leptin expressionregardless the presence of E2. Endogenous GR was not able to bedetected in BeWo cells. However, overexpression of a recombinantGR-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 and56 KDa isoforms and probably mediates the regulation of leptin expressionby DEX.