Mapping the Proteomic Landscape of Congenital Aortic Valve Stenosis Using a Notch1;Gata5 Mutant Mouse Model

Congenital aortic valve stenosis (AVS) is a severe form of congenital heart disease, accounting for 3–6% of cases. Characterized by malformed aortic valves that obstruct blood flow, AVS can potentially lead to heart failure or death without timely surgical intervention. Current treatments rely on catheter or surgical interventions, often multiple, due to a limited understanding of its molecular basis. To address this gap, we leveraged our Notch1+/-;Gata5-/- AVS mouse model and performed proteomic analysis of aortic valves at postnatal day 10 using HPLC-MS. Our aim was to identify early molecular changes, clinically relevant biomarkers, and potential therapeutic targets. A healthy aortic valve is composed of three distinct extracellular matrix (ECM) layers with valve interstitial cells (VICs) interspersed within them, and valve endothelial cells lining the surface. VICs play a key role in synthesizing ECM components that preserve valve structure and function. We detected significant alterations in 364 proteins, with ~9% involved in ECM organization, supporting impaired valve remodeling in AVS. Notably, integrin proteins, which are associated with TGF-β signaling and ECM remodeling, were significantly elevated in mutant valves and are linked to VIC activation. The additional finding of dysregulated smooth muscle markers suggests aberrant activation driving maladaptive valve thickening. Network analysis further identified CTNNB1 as a potential upstream regulator, suggesting activation of the Wnt signaling pathway, a possible driver of aberrant ECM synthesis. Together, these findings provide insight into early molecular changes in congenital AVS and identify candidate pathways for biomarker development and therapeutic intervention.