Objective:

To investigate vascular cell states in Marfan syndrome and understand aneurysm-associated changes in the aortic wall.

Key Findings:

• Identified 16 cell groups, including seven distinct smooth muscle cell subtypes.
• Altered smooth muscle cell states were more abundant in Marfan tissue.
• Endothelial cells showed signs of endothelial-to-mesenchymal transition.
• Proteomic and transcriptomic data agreed well for broad cell classes but less so for smooth muscle subtypes.

Interpretation:

The study reveals significant heterogeneity in vascular cell states in Marfan syndrome, suggesting that specific markers may indicate either pathogenic remodeling or compensatory responses during aneurysm progression.

Limitations:

• The study primarily focuses on mouse models, which may not fully replicate human Marfan syndrome.
• Some phenotypic differences may not be fully resolved by RNA data alone.

Conclusion:

The newly defined smooth muscle populations warrant further functional studies to clarify their roles in Marfan aneurysm progression.