Summary
The placenta is a highly vascularized organ with fetal and maternal blood supply.
Syncytiotrophoblasts (STB), which line the placenta villous are possibly involved
in local hemostatic mechanisms.The aim of this study was to evaluate the levels of
tissue factor (TF) and its inhibitors, tissue factor pathway inhibitor (TFPI,TFPI-2),
in STB model within hemostatic and inflammatory environments. Human primary STB cell
cultures were characterized by vascular and hormonal markers. TF and TFPI mRNA expression,
protein levels and activity were determined and compared to human umbilical vein endothelial
cells (HUVEC). High levels of TF were demonstrated in STB cells compared to low levels
in HUVEC. In contrast, STB expressed lower TFPI levels than HUVEC. LPS and TNFα increased
the high constitutive TF in STB, whereas LPS and IL-1α further reduced TFPI levels.
The procoagulant tendency of STB identified by us may reflect the physiological need
for immediate inhibition of hemorrhage in the placental inter-villous spaces in basal
and inflammatory conditions.This hemostatic balance may be critical for normal placental
function and pregnancy outcome.
Keywords
Tissue factor - tissue factor pathway inhibitor (TFPI) - placenta - trophoblast -
inflammation