Long-Term Neurovascular Dysfunction and Altered Placenta-Derived EV miRNA Profiles in a Rat Model with Preeclamptic Features

Objective: Preeclampsia increases long-term cardiovascular, cerebrovascular, and cognitive risk but the underlying mechanisms remain unclear. We examined cerebrovascular function, cognitive performance, and placenta-derived extracellular-vesicle (PD-EV) microRNA profiles in a transgenic rat model with preeclamptic features (TGA-PE) at 2 months after delivery (2M). Methods: Middle cerebral artery (MCA) hemodynamics were assessed by transcranial Doppler (TCD), and cerebral oxygenation was measured by photoacoustic imaging (PAI) in TGA-PE and Sprague-Dawley control rats. Blood pressure was measured using a tail-cuff method. Touchscreen-based cognitive tasks evaluated learning and reward-directed responding, while histological assessment evaluated MCA structure. MicroRNA sequencing was performed on circulating PD-EV, and miRNA target networks were analyzed using KEGG-based NEST-Scoring (Node, Edge, System, Topology). Validation of miR-363-3p was performed in PD-EV, plasma, non-PD-EV, and human brain endothelial cells (HBEC-5i). Results: TGA-PE rats were hypertensive and exhibited lower MCA resistance and pulsatility indexes with unchanged blood flow velocities. Cognitive testing revealed impaired associative learning and reduced motivation to respond on a progressive-ratio schedule. Temporal brain oxygen saturation was higher in TGA-PE rats with unchanged total hemoglobin, lower brain HIF-2, and unchanged VEGF levels. MCA elastin content was reduced in TGA-PE rats without changes in total collagen. PD-EV sequencing identified 29 differentially expressed miRNAs, including reduced miR-363-3p in non-placental EVs and plasma at 2M. Inhibition of miR-363-3p in human cerebral endothelial cell line HBEC-5i upregulated NOX4, p21, and {beta}-galactosidase levels. NEST-Scoring highlighted pathways involving MAPK, Ras, TNF, focal adhesion, cytoskeletal regulation, and cellular senescence. Conclusions: The exposure to experimental preeclampsia resulted in altered MCA flow resistance, cerebral oxygenation, vascular structure and behavioral performance. Although direct mechanistic studies are needed to establish the role of miRNA363-3p in neurovascular health, the increased endothelial oxidative stress and senescence-associated markers in HBEC-5i cells in response to miRNA363-3p inhibition suggest a potential protective role for miRNA363-3p. A novel NEST-Scoring analysis also identified potential pathways for future mechanistic investigations. Overall, the TGA-PE model provides a useful experimental system for investigating candidate mechanisms that may contribute to long-term maternal neurovascular changes following hypertensive pregnancy and sequelae of preeclamptic pathophysiology.