Fibronectin-induced overactivation of α<sub>V</sub>β<sub>3</sub>-PI3K-PIP3-PDK1-ILK signaling drives aortic disease in Marfan syndrome.

Alarcón-Ruiz, Iván; Ruiz-Rodríguez, María Jesús; Martínez-Martínez, Sara; Toral, Marta; Martín-Bermejo, Noelia; Mateos-García, Sergio; Gil-Ruiz, Teresa; Herrero-Galán, Elías et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Thoracic aortic aneurysms and dissections (TAAD), a life-threatening complication of Marfan syndrome (MFS), lack curative therapies. Our previous studies revealed that versican accumulation drives MFS aortopathy through AKT-NO pathway overactivation, but the upstream mechanisms remained unclear. Here, we show that versican-driven fibronectin (FN) accumulation activates an α<sub>V</sub>β<sub>3</sub>-PI3K-PIP3-PDK1-ILK signaling cascade leading to AKT-NOS2 upregulation and aortic disease. FN accumulates in aortas of MFS patients and mice of both sexes and correlates with increased α<sub>V</sub>β<sub>3</sub> integrin and ILK expression. Disrupting FN assembly or inhibiting α<sub>V</sub>β<sub>3</sub>, PI3K, PIP3, PDK1 or ILK prevents FN-induced AKT activation and NOS2 upregulation, restores vascular contractility, and limits aortic dilation in MFS mice. Inhibition of ILK or PDK1, aortic silencing of Ilk, or smooth muscle-specific deletion of Ilk reverses or prevents aortic growth. Together, these findings define a mechanistically integrated FN-α<sub>V</sub>β<sub>3</sub>-PI3K-PIP3-PDK1-ILK-AKT-NOS2 signaling cascade in MFS and support its causative role in human TAAD, highlighting its components as potential targets for therapeutic intervention.