Vascular Adventitia Calcification and Its Underlying Mechanism

Area of Science:

• Cardiovascular Biology
• Vascular Biology
• Pathology

Background:

• Vascular calcification research has historically focused on the intima and media.
• The adventitia's role in vascular calcification remains under-explored.

Purpose of the Study:

• To investigate the potential for vascular calcification in the adventitia.
• To elucidate the pathogenic mechanisms of adventitial vascular calcification.

Main Methods:

• Examined calcified lesions in ApoE-/- mice on high-fat diets and elderly human subjects using Von Kossa staining.
• Induction of calcification in explant cultured adventitial fibroblasts and medial smooth muscle cells (SMCs) from rats, followed by Alizarin Red S staining.
• Investigated fibroblast to myofibroblast phenotype conversion.

Main Results:

• Calcified lesions were identified in the aorta and coronary artery adventitia of mice.
• Adventitial calcification was also observed in human aorta samples.
• Adventitial fibroblasts were successfully induced to calcify and undergo phenotype conversion; medial SMCs also calcified.

Conclusions:

• Vascular calcification is not limited to the intima and media; it can occur in the adventitia.
• Adventitial calcification may originate from transformed adventitial fibroblasts (myofibroblasts) or SMCs.