Change in elastin structure in human aortic connective tissue diseases.

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Connective Tissue Diseases

Background:

• Aortic connective tissue diseases, including Marfan syndrome and aneurysms, have complex biochemical underpinnings.
• Understanding the role of elastin and its cross-linking is crucial for elucidating disease pathogenesis.

Purpose of the Study:

• To investigate the biochemical changes in aortic connective tissue, focusing on elastin and its cross-linking components.
• To compare these components in patients with aortic diseases versus control subjects.

Main Methods:

• Quantification of glycoprotein, collagen, and elastin content in aortic tissue.
• Analysis of intramolecular (isodesmosine) and intermolecular (cystine, histidinoalanine) cross-linking components.
• Measurement of serum elastase and elastase-like activities.

Main Results:

• Decreased aortic elastin and isodesmosine content were observed in disease states.
• An increased ratio of cysteine residues in the elastin fraction and decreased histidinoalanine were noted.
• Increased immunoreactive elastin and elevated serum elastase activity suggest elastin degradation susceptibility.

Conclusions:

• Defects in elastin's intra- and inter-molecular cross-linking may compromise aortic structural integrity.
• A molecular defect in fibillin or other glycoproteins could lead to deficient elastin-associated microfibrils and inadequate cross-linking.
• These alterations render the aorta more susceptible to proteolytic enzymes and disease progression.