Thromboxane and Prostacyclin Production of Trophoblast Cells After Very Low-Density Lipoprotein Incubation

Abstract

Objective: To test the effects of native VLDL (nVLDL) and oxidized VLDL (oxVLDL) on thromboxane and prostacyclin release from syncytiotrophoblasts in an in vitro model.

Study Design: After isolation and Percoll centrifugation, three series of syncytiotrophoblast cell cultures were prepared for determination of thromboxane B₂ (T×B₂) and 6-keto prostaglandin (PG)_lα, the stable metabolites of thromboxane and prostacyclin: a standard cell culture, a cell culture incubated with nVLDL, and a cell culture incubated with ox VLDL. Samples were taken at 2 and 24 h of incubation, and the changes in concentration were compared among cultures.

Results: Production of T×B₂ decreased in the standard cell culture (P = 0.0001), but increased after incubation with nVLDL (P = 0.01) or ox VLDL. Release of 6-keto PG_1α remained largely unchanged in the standard cell culture, but increased in nVLDL (P = 0.02) and oxVLDL incubated cells. Comparisons among cell cultures showed that the production of T×B₂ was significantly higher in cells exposed to nVLDL (P = 0.0002) or oxVLDL (P = 0.0075) than in unstimulated cells. 6-Keto PG_1α production increased significantly in nVLDL incubated cells (P = 0.02), whereas a nonsignificant increase was seen in oxVLDL incubated cells.

Conclusion: Trophoblast cells release thromboxane and prostacyclin after lipid incubation. The release of thromboxane and prostacyclin from syncytiotrophoblasts after incubation with VLDL shows a pattern similar to that described for endothelial cells after addition of sera from preeclamptic patients. This could be interpreted as evidence for a causative role of VLDL in the pathophysiology of pre-eclampsia.

Key Words:

• Trophoblast culture
• Very low-density lipoprotein
• Preeclampsia