Antiangiogenic plasma activity in patients with systemic sclerosis

Area of Science:

• Vascular Biology
• Immunology
• Rheumatology

Background:

• Systemic sclerosis (SSc) is a connective tissue disease characterized by vascular abnormalities and poor wound healing.
• Aberrant microvasculature and impaired wound healing are key features of SSc.

Purpose of the Study:

• To investigate the presence and role of antiangiogenic factors in patients with SSc.
• To determine if SSc plasma affects endothelial cell function.

Main Methods:

• Plasma samples from 30 SSc patients and 10 controls were analyzed.
• Endothelial cell migration and vascular structure formation assays were performed.
• Levels of angiostatin and its production mechanisms were assessed.

Main Results:

• SSc plasma significantly reduced endothelial cell migration and tube formation compared to control plasma.
• SSc plasma exhibited 2.9-fold higher levels of angiostatin (plasminogen kringle 1-3 fragments).
• Granzyme B and other proteases in T cell granules were identified as key mediators in cleaving plasminogen into angiostatin.

Conclusions:

• Elevated angiostatin levels in SSc patients contribute to the inhibition of proangiogenic processes.
• The interaction between plasminogen conformation, granzyme B, and proteases leads to increased antiangiogenic angiostatin.
• Increased angiostatin production is a potential mechanism underlying vascular defects in systemic sclerosis.