Demonstration of inducible TFPI-2 mRNA synthesis in BeWo and JEG-3 trophoblast cells using a competitive RT-PCR.

ABSTRACT

Tissue factor pathway inhibitor-2 (TFPI-2) displays structural similarities with TFPI-1, the major inhibitor of tissue factor (TF)/, factor VIIa. It is synthesized mostly by syncytiotrophoblast in the placenta, but its physiological functions are not fully understood. We studied the synthesis of TFPI-2 mRNA and that of TFPI-1 and TF in three human trophoblast cell lines, JAR, BeWo, and JEG-3. We first developed specific competitive reverse transcription-polymerase chain reaction (RT-PCR) assays for each gene studied using human umbilical vein endothelial cells (HUVEC). The three trophoblast cell lines strongly synthesized TF mRNA whereas the synthesis of TFPI-1 mRNA was very low. TFPI-2 mRNA was not detected in unstimulated or stimulated JAR cells. In contrast, JEG-3 and, to a lesser extent, BeWo produced significant amounts of TFPI-2 mRNA, which were significantly increased after stimulation with phorbol 12-myristate 13-acetate (PMA). However, tumor necrosis factor-alpha (TNF-alpha) had no effect on this synthesis. JEG-3 and BeWo are thus two cell lines that could be used to study TFPI-2 gene regulation and to investigate the role of TF, TFPI-1, and TFPI-2 during trophoblast differentiation.