The Efficacy of Antihypertensive Drugs and miR-632 Inhibition on Parietal Remodeling in a Model of Marfan Thoracic Aortic Aneurysm.

BACKGROUND

Marfan syndrome (MFS) is a connective tissue disorder caused by FBN1 mutations, leading to elastic fiber disarray and early thoracic aortic aneurysm (TAA) formation. Currently, pharmacological treatments lack specificity and only delay progression. We previously reported a specific TGFβ-driven miR-632 upregulation in MFS TAA tissues and blood causing smooth muscle cell dedifferentiation and aortic wall degeneration. This study evaluated the effects of three conventional antihypertensive drugs (β-blocker, ACE inhibitor, and sartan) on parietal remodeling, comparing them with a miR-632 inhibitor in an ex vivo TGFβ1-induced model of MFS TAA.

METHODS AND

RESULTS

Using an ex vivo paired experimental framework based on independent biological pools of human TAA tissue, gene expression and Western blot analyses demonstrated that only losartan significantly reduced miR-632 and vascular degeneration markers. Notably, combined treatment with ramipril and carvedilol compromised losartan's efficacy, highlighting the need for careful therapeutic selection. In this ex vivo setting, miR-632 inhibition demonstrated a promising capacity to counteract aortic remodeling, serving as a mechanistic proof-of-concept that warrants further preclinical in vivo validation.

CONCLUSIONS

Our data emphasize that choosing the right treatment in MFS aortopathy requires understanding its specific impact on cellular pathways. Our findings identify losartan as the most effective standard drug in this model, while suggesting miR-632 as a potential future target to stabilize the aortic wall and, prospectively, delay surgery.