Early Aberrant Angiogenesis Due to Elastic Fiber Fragmentation in Aortic Valve Disease

Area of Science:

• Cardiovascular Biology
• Pathology
• Vascular Biology

Background:

• Elastic fiber fragmentation (EFF) is a key feature of aortic valve disease (AVD).
• Neovascularization is typically a late finding associated with inflammation in AVD.
• The relationship between early EFF and aberrant angiogenesis in AVD requires further investigation.

Purpose of the Study:

• To characterize the association between early elastic fiber fragmentation and aberrant angiogenesis in aortic valve disease.
• To investigate the role of EFF in the early stages of AVD progression.
• To analyze the impact of EFF on angiogenesis in syndromic AVD (Williams and Marfan syndromes).

Main Methods:

• Histochemistry, immunohistochemistry, and electron microscopy were used to analyze aortic valve tissue.
• Specimens from early-onset (<40 years) and late-onset (≥40 years) non-syndromic AVD patients were examined.
• Aortic valve tissue from patients with Williams syndrome and Marfan syndrome was also analyzed.

Main Results:

• Early-onset AVD showed angiogenesis without inflammation or atherosclerosis.
• Neovessels in early-onset AVD were surrounded by specific elastic fiber components (increased emilin-1, decreased fibulin-5).
• Angiogenesis was observed in Williams syndrome but not Marfan syndrome aortic valves, with distinct EFF patterns.

Conclusions:

• Aberrant angiogenesis occurs in early-onset AVD independently of inflammation, suggesting a role for elastic fiber fragmentation.
• The distinct elastic fiber changes in early AVD and syndromic cases provide insights into disease mechanisms.
• Understanding these mechanisms could lead to novel pharmacological treatments for AVD.