The Role Of TFPI-2 In Preeclampsia Pathology

ObjectiveThis study aims to detect the TFPI-2 expression in serum and placenta by Time-resolved fluoroimmunoassay and immunochemistry, respectively, and analyize the role of TFPI-2 in biology of BeWo cell line, including invasion, proliferation, apoptosis and differentiation.MethodsWe assessed the plasma TFPI-2 level in non-pregnant, normal pregnant and postpartum women, detected fetal plasma level and expression in placenta, and compared the changes in women with preeclampsia. TR-IMFA and immunohistochemistry were used for plasma and placenta tissue detection, respectively. After transfected TFPI-2 gene expression in BeWo cells, cell functions were assessed, including boyden chamber for invasion, cell counting kit-8 (CCK-8) for proliferation, Hochest staining, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry cycle analysis for apoptosis, and enzyme-linked immunosorbent assay of detection of human chorionic gonadotropin (β-hCG) level for differentiation.ResultsMaternal plasma levels of TFPI-2 in normal pregnant women at 13 weeks of gestation increased 9.3 times as compared with healthy non-pregnant women (149.3±17.1 versus 16.0±3.6ng/ml), reached a maximum level (282.6±17.1ng/ml) at 39 weeks of gestation, and dramatically decreased to nearly a non-pregnant level on the first day of postpartum (32.3±7.1ng/ml); similar change was found in the placental expression. Fetal plasma TFPI-2 was significantly lower than the maternal level at delivery. The maternal plasma TFPI-2 in preeclampsia was significantly lower compared with that in normal pregnancy, coupled with significantly higher placental expression. In BeWo cell line in vitro, increased TFPI-2 expression slightly inhibited the migration and invasiveness (p<0.05); decreased TFPI-2 expression significantly promoted the migration and invasiveness (p<0.05). In each group, cell viability was significantly inhibited in the second day of transfection, and gradually increased in the 4thday to 8thday. Cell viability was significantly reduced along with the expression of TFPI-2 (p<0.05). Also, apoptosis index and TUNEL positive rate increased with the expression of TFPI-2 in parallel (p<0.05). TFPI-2 expression had no significant effect on the secretion ofβ-hCG (p>0.05).Conclusions1. Placenta may be the main source of TFPI-2 during pregnancy.2. TFPI-2 is important for pregnancy maintenance.3. TFPI-2 expression inhibits invasion and proliferation in trophoblast, and induces apoptosis, which provides a clue for preeclampsia pathology.Novelty1. Our study firstly reported the specific function of TFPI-2 in trophoblast cell, including cell invasion, proliferation, apoptosis and differentiation.2. In our study, both clinical research and in vitro cell method, by the approach of immunochemistry, transfection, and so on, were applied for verifying the role of TFPI-2 in the preeclampsia pathogenesis.