3,5,3′-Triiodothyronine Down-Regulates Fas and Fas Ligand Expression and Suppresses Caspase-3 and Poly (Adenosine 5′-Diphosphate-Ribose) Polymerase Cleavage and Apoptosis in Early Placental Extravillous Trophoblasts in Vitro

The present study was conducted to determine whether T3 receptor exists in early placental extravillous trophoblasts (EVTs) and evaluate the influence of T3 on Fas/Fas ligand expression, caspase-3, and poly (ADP-ribose) polymerase (PARP) cleavage and apoptosis in cultured early placental EVTs. EVTs with invasive phenotype, isolated from normal placental explants from early pregnancy through preincubation on human fibronectin-coated dishes and exhibited cytokeratin 7 and human placental lactogen immunopositive staining, were cultured in the absence or presence of T3 (10−7 to 10−9 m). The presence of T3 receptor in cultured EVTs was examined by immunocytochemistry, RT-PCR, and Southern blot analysis. Fas sensitivity was determined by treating the cells with an agonistic Fas antibody. Apoptosis was assessed by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling, flow cytometry, and Hoechst nuclear staining. Fas and Fas ligand expression and caspase-3 and PARP cleavage were evalu...