A Conotoxin-Derived Peptide Selectively Inhibits PAR-1 Mediated Thrombosis and Neutrophil Extracellular Traps Formation Without Affecting Hemostasis

Thrombosis is the key driver for ischemic events including stroke, which is the leading cause of global mortality. However, current antithrombotic therapies carry substantial bleeding risks. Targeting protease-activated receptor-1 (PAR-1), a thrombin-activated receptor central to thrombus growth, represents a promising antithrombotic strategy for safer intervention. Here, we mined the venom gland transcriptome of Conus spp., applied in silico Furin cleavage prediction, synthesized and screened the antiPAR-1 activity of a series of conotoxin-derived peptides. Among them, Cb-26 exhibited the strongest but reversible activity in inhibiting PAR-1 mediated platelet activation and aggregation in vitro. Crucially, Cb-26 inhibited platelet adhesion, neutrophil extracellular traps formation and thrombus growth under shear conditions in whole blood from healthy donors. In murine models, Cb-26 significantly delayed carotid occlusion and reduced cerebral infarct size in photochemical-induced ischemic stroke, without affecting blood coagulation and bleeding time. These results suggest that Cb-26 is a selective and reversible PAR-1 antagonist, and represents a promising antithrombotic candidate without apparent bleeding side effect.