Abstract 129: A Biopolymer-Stabilized VEGF Chimera Reverses Angiogenic Imbalance in vitro in the Reduced Uterine Perfusion Pressure Model of Preeclampsia
Preeclampsia (PE) is a hypertensive disorder that complicates approximately 5-8% of all pregnancies in the U.S. The unknown etiology of PE develops from molecular dysfunction at the maternal-placental interface, where inflammatory, oxidative stress, and anti-angiogenic pathways are initiated. The resulting hypoxic in utero environment contributes to placental ischemia from which the anti-angiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1) is released. A truncated isoform, sFlt-1 consists solely of the extracellular domain of the vascular endothelial growth factor (VEGF) receptor 1, and hence lacks both catalytic and regulatory activities. However, sFlt-1 retains a high affinity for VEGF and sequesters this ligand from binding with fully functional VEGF receptors, thus prevents the activation of angiogenic remodeling pathways. The rodent model of PE, reduced uterine perfusion pressure (RUPP), exhibits the sFlt-1 pathophysiology observed in human PE. In an effort to counteract excessive sFlt-1 production and restore angiogenic balance, we have constructed a VEGF chimera fused to an Elastin-like Polypeptide (ELP) carrier with increased in vivo half-life and stability which retains full VEGF signaling activity. When human umbilical vein vascular endothelial cells (HUVECs) are exposed to serum from normal pregnant or RUPP-treated rats, tube formation on extracellular matrix is inhibited 31% (± 2%) by the RUPP serum. This inhibition is reversed when ELP-VEGF, but not ELP control, is added to the culture medium (p = 0.0007, one-way ANOVA with Bonferroni multiple comparison), suggesting that ELP-VEGF counteracts the anti-angiogenic factors present in RUPP serum. We also characterized the pharmacokinetics, biodistribution, and placental transfer of ELP-VEGF in the pregnant Sprague Dawley rat. These
studies indicate that ELP-delivered VEGF has potential for counteracting the circulating anti-angiogenic factors in maternal plasma.
Author Disclosures: O.C. Logue: None. F. Mahdi: None. E.M. George: None. G.L. Bidwell: B. Research Grant (includes principal investigator, collaborator, or consultant and pending grants as well as grants already received); Modest; Research Grant 13SDG-16490006. F. Ownership Interest (includes any stock, stock option, partnership, membership or other equity position in an entity regardless of the form of the entity, or any option or right to acquire such position, and any rights in any patent or other intellectu; Modest; Leflore Technologies.
This research has received full or partial funding support from the American Heart Association, National Center.
- © 2015 by American Heart Association, Inc.