The decidual cells were seeded onto polystyrene tissue culture dishes that were precoated with 2% type B gelatin (Sigma Chemical Co.). The cultures were grown to confluence in 5% CO2 in air at 37°C, and passaged three times. Fluorescent antibody cell sorting for the presence of CD45 + demonstrated that unpassaged cultures contained 12-15% CD45+ cells, while the passaged cultures were >99% negative for this common leukocyte marker. The latter cell populations were used for the subsequent experimental cell incubations. The cultured cells were vimentin-positive and cytokeratin-negative.
The cultured cells also showed decidualization-related morphological changes and expressed elevated levels of prolactin, tissue factor, and plasminogen activator inhibitor type 1 under the influence of estradiol (E2) plus medroxyprogesterone acetate (MPA).
Experimental Cell Incubations
Confluent decidual cultures, each obtained from an individual specimen, were primed for 7 days in BM supplemented with SCS that contained either vehicle control (0.1% ethanol), 10_8 M E2, 10_7 M MPA (Sigma) or E2 plus 10_7 M MPA with one change of medium.