25 Low dose aspirin corrects in vitro the placental cell derived sFlt-1/PlGF imbalance characteristic of preeclampsia

Abstract

Introduction Preeclampsia (PE) is a multi-system disorder typically involving pregnancy-induced maternal hypertension and proteinuria presenting in the second half of pregnancy. The placenta is the key organ responsible for the pathogenesis of PE, with altered release of placenta-derived anti- (eg sFlt-1) and pro- (eg PlGF) angiogenic proteins implicated in maternal PE pathophysiological events. Epidemiological data indicate that low-dose aspirin (LDA) commenced before 16 weeks gestation is clinically effective in preventing PE, but its mechanism of action is unclear. We hypothesized that the prophylactic efficacy of LDA treatment may be associated with a corrective effect of LDA on the altered release of placenta-derived angiogenic proteins seen in PE pregnancies. Objective To test this hypothesis, we examined the effects of pregnancy sera from normotensive and PE cases with and without LDA on the in vitro production and release of sFlt-1 and PlGF from a trophoblast-derived cell line (BeWo). Methods The effects of LDA (5 μg/mL) following treatment of BeWo cells in vitro with either PE or normotensive serum on the expression of angiogenic proteins sFlt-1 and PlGF were determined using real-time PCR. The secretion of these angiogenic proteins in the conditioned media was screened with a commercially designed protein array. Candidate protein validation was then performed using an ELISA. All experiments were performed in triplicate at least six independent occasions. A p-value Results Angiogenic profiling at the mRNA level identified significantly increased expression of Flt-1 [Normotensive: 1.04 ± 0.03 vs PE: 2.68 ± 0.07, p Conclusion Increased placental release of the anti-angiogenic protein sFlt-1 and reduced placental release of the pro-angiogenic protein PlGF into the maternal circulation are key contributors to the maternal vascular endothelial cell dysfunction that is central to the development of the maternal syndrome of PE. The ability of LDA to rebalance these key angiogenic proteins in an in vitro trophoblast cell-line model may offer an important mechanistic insight at a molecular level regarding the clinical utility of LDA in preventing PE.