The expression of the placental anticoagulant protein, annexin V, by villous trophoblasts: immunolocalization and in vitro regulation. Academic Article uri icon

Overview

abstract

  • We evaluated the histological and ultrastructural localization of the potent anticoagulant protein, annexin V, at the light and electron microscopic levels, using immunohistochemistry and an immunogold method. Annexin V was found to localize to the microvillar surface of the villous syncytiotrophoblasts. Isolated villous-derived trophoblasts were then utilized to evaluate the expression of annexin 1 protein mRNA in response to syncytialization in vitro, as well as to exposure to adenylate cyclase and protein kinase C agonists. Levels of immunoreactive annexin V released into the conditioned media and associated with cell protein were assessed by ELISA while levels of annexin V mRNA were evaluated by Northern analysis. No significant change in either media or cell-associated annexin V concentrations were detected over time in culture or in response to 1.5 mM 8-bromo-cyclic-adenosine-monophosphate (8-b-cAMP) or 0.15 nM phorbol ester myristic acid (PMA). These results indicate that annexin V is ideally positioned to inhibit intervillous thrombosis and maintain the fluidity of the intervillous circulation. Moreover, the absence of trophoblast annexin V regulation by intracellular second messenger regulators suggests that this crucial placental anticoagulant factor is constitutively produced.

publication date

  • September 1, 1994

Research

keywords

  • Annexin A5
  • Trophoblasts

Identity

Scopus Document Identifier

  • 0027933860

Digital Object Identifier (DOI)

  • 10.1016/s0143-4004(05)80407-2

PubMed ID

  • 7824446

Additional Document Info

volume

  • 15

issue

  • 6