Targeting pathogenic VWF/ADAMTS13 dysregulation attenuates CTEPH progression.

Area of Science:

• Cardiovascular Biology
• Hematology
• Pulmonary Hypertension Research

Background:

• Chronic thromboembolic pulmonary hypertension (CTEPH) involves persistent thrombosis and vascular remodeling, but underlying molecular mechanisms are unclear.
• Elevated von Willebrand factor (VWF) and reduced ADAMTS13 are observed in CTEPH patients, suggesting a role for this axis.
• The direct contribution of VWF/ADAMTS13 dysregulation to CTEPH pathogenesis requires elucidation.

Purpose of the Study:

• To investigate the causative role of VWF-ADAMTS13 axis dysregulation in the progression of chronic thromboembolic pulmonary hypertension (CTEPH).
• To explore the mechanistic links between VWF-ADAMTS13 imbalance, thrombosis, and vascular remodeling in CTEPH.
• To evaluate the therapeutic potential of modulating the VWF-ADAMTS13 pathway in CTEPH.

Main Methods:

• Established rat models of CTEPH to study VWF and ADAMTS13 dynamics.
• Utilized genetic manipulation (Adamts13 deficiency, Vwf ablation) and recombinant ADAMTS13 treatment.
• Assessed thrombus formation, endothelial VWF deposition, platelet recruitment, vascular remodeling, and pulmonary hemodynamics.

Main Results:

• CTEPH rats exhibited persistent VWF-rich thrombi, increased endothelial VWF, and reduced ADAMTS13 expression/activity.
• Genetic Adamts13 deficiency exacerbated thrombosis and mortality; Vwf ablation reduced thrombosis, remodeling, and improved hemodynamics.
• Recombinant ADAMTS13 treatment decreased UL-VWF, suppressed platelet activation, and prevented thrombosis and remodeling in CTEPH rats.

Conclusions:

• VWF-ADAMTS13 axis dysregulation is a key driver of pulmonary thrombosis and vascular remodeling in CTEPH.
• Ultra-large VWF (UL-VWF) accumulation promotes platelet recruitment and release of pro-remodeling mediators.
• Targeting the VWF-ADAMTS13 pathway, via recombinant ADAMTS13 or VWF inhibition, represents a promising therapeutic strategy for CTEPH.