MON-152 Regulation of Angiogenic Biomarkers of Pre-eclampsia in a Placental Trophoblast Model

Abstract Disclosure: H.M. Hooker: None. D. Grammatopoulos: None. Pre-eclampsia (PE) is a multi-system pregnancy disorder and a leading cause of maternal and neonatal morbidity and mortality worldwide. Recent clinical practice for PE incorporates measurement of the ratio between two angiogenic markers, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) in blood. Abnormal levels of sFlt-1 and PlGF are secreted from a dysfunctional placenta in PE into the maternal bloodstream, causing widespread maternal endothelial dysfunction. Whilst use of the ratio is a major advancement in early prediction and risk stratification for women with suspected PE, the biological mechanisms regulating the secretion patterns of these key angiogenic biomarkers remain poorly understood. This study aimed to implement a model of angiogenic biomarker secretion from placental trophoblasts, using the BeWo choriocarcinoma cell line, to examine the effects of potential regulators, focussing on corticotrophin releasing hormone (CRH), a major homeostatic regulator of fetomaternal communication, and glucose availability on the mRNA expression and secretion of sFlt-1 and PlGF. BeWo cells were differentiated into a syncytiotrophoblast-like state using 50μM forskolin for 48hrs, a cyclic AMP pathway activator. Forskolin treatment resulted in a substantial 3- to 4-fold increase in PlGF mRNA expression and Western blot analysis showed increased phosphorylation of cAMP-response element binding protein (CREB), a known PlGF transcription factor, indicating regulation of PlGF via the cAMP pathway. In contrast, a marginal increase in sFlt-1 mRNA was observed in forskolin-treated cells, suggesting no direct sFlt-1 control via cAMP in BeWo cells. Untreated BeWo cells exhibited a 250-fold greater expression of PlGF than sFlt-1, rising to 625-fold in forskolin-treated cells.CRH had little effect on undifferentiated cells but in differentiated cells CRH appears to promote PlGF expression and inhibit sFlt-1 expression. However, dose-response experiments identified that at higher concentrations, CRH effects may be diminished through downregulation of the CRH receptor. Moreover, in differentiated cells, an inverse relationship was observed between glucose availability and expression of PlGF and human chorionic gonadotrophin. In contrast, in both undifferentiated and differentiated cells, increased glucose availability resulted in a small but statistically significant increase in sFlt-1 expression. Overall, we have demonstrated significant PlGF expression in BeWo cells that appears to be under the regulation of placental hormones such as CRH as well as glucose availability. Understanding how these placental regulators affect the secretion of sFlt-1 and PlGF advances current knowledge of the pathogenesis of PE and how known risk factors such as gestational diabetes and high-stress pregnancies affect PE phenotype and sFlt-1/PlGF ratio levels. Presentation: Monday, July 14, 2025