Circulating platelet-derived and placenta-derived microparticles expose Flt-1 in preeclampsia

Reprod Sci. 2008 Dec;15(10):1002-10. doi: 10.1177/1933719108324133. Epub 2008 Oct 20.


Background: Flt-1 is secreted by various cells and elevated concentrations are present in preeclampsia affecting vascular function. Microparticles from these cells may expose Flt-1. We evaluated whether Flt-1 is microparticle-associated in preeclampsia, and established the origin of Flt-1-exposing microparticles.

Methods: The concentration of Flt-1 was measured in samples from preeclamptic patients, pregnant and nonpregnant women by enzyme-linked immunosorbent assay. Microparticles were analyzed by flow cytometry. Western blot determined the different forms of Flt-1.

Results: Noncell bound Flt-1 was elevated in preeclampsia compared to controls. A fraction (5%) was associated with microparticles in preeclampsia. Flt-1-exposing microparticles were increased in preeclampsia compared to normotensive pregnancy (p = 0.02). Full-length Flt-1, was identified in microparticles of platelet and placental origin.

Conclusion: Full-length Flt-1 is associated with platelet and placenta-derived microparticles. Possibly, the presentation of Flt-1 on the membrane of a microparticle might alter its function, particularly if it acts in synergism with other exposed vasoactive molecules.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Blood Platelets / metabolism*
  • Cell-Derived Microparticles / metabolism*
  • Female
  • Humans
  • Infant, Newborn
  • Placenta / metabolism*
  • Pre-Eclampsia / blood*
  • Pregnancy
  • Vascular Endothelial Growth Factor Receptor-1 / blood*


  • FLT1 protein, human
  • Vascular Endothelial Growth Factor Receptor-1