Journal of Glycobiology
Open Access

Abstract

The Role of Placental Glycosaminoglycans in the Prevention of Pre-Eclampsia

Tilini Gunatillake, Amy Chui and Joanne M Said

Uncomplicated pregnancies represent a hypercoagulable state. However, placental thrombosis is rare in these pregnancies which suggest that thrombin generation must be tightly regulated. In contrast, pregnancy disorders such as pre-eclampsia (PE) demonstrate an exaggerated increase in pro-coagulant activity contributing to the thrombotic lesions observed in the uteroplacental circulation of these pregnancies. Therefore, the tight haemostatic regulation observed in uncomplicated pregnancies is disrupted in PE-affected pregnancies.

Glycosaminoglycans (GAGs) are abundantly expressed within the placenta. GAGs do not exist in isolation, but are predominately bound to proteins known as proteoglycans (PGs). PGs have important anticoagulant, antiinflammatory and pro-angiogenic properties. Placentae from pregnancies complicated by PE demonstrate a reduction in PG expression. This may be a plausible explanation for the increase in thrombosis observed in this pregnancy complication.

Heparin is a well known pharmacological GAG with biochemical structure similar to the endogenous GAG, heparan sulphate (HS). Recent clinical studies have suggested that antenatal heparin therapy may reduce the likelihood of developing PE and fetal growth restriction (FGR). However, the mechanism by which heparin acts to reduce the likelihood of such pregnancy complications is very poorly understood and is necessary in order to improve the efficacy of this drug before it is to be used as a standard treatment.