Brain-derived microvesicles induce activation of aspirin-treated platelets via the PLC/PKC pathway

Aspirin (Asp) therapy reduces the risk of arterial thrombotic events. However, aspirin-related adverse effects, particularly cerebral hemorrhage with its high mortality and disability rates, remain a significant concern. Interestingly, long-term antiplatelet therapy does not appear to exacerbate bleeding severity in patients with hemorrhagic cerebrovascular disease, suggesting potential compensatory mechanisms inducing platelet activation post-hemorrhage. Brain-derived microvesicles (BDMVs) have been implicated in platelet activation, although the underlying molecular mechanisms are unclear. This study employed flow cytometry (FCM), ELISA, and hopping probe ion conductance microscopy (HPICM) to demonstrate that BDMVs significantly activate and induce morphological changes in aspirin-treated platelets. We discovered the presence of cyclooxygenase-1 (COX-1) on BDMVs. Then, the phosphorylated proteomics was used to analyze the effect of BDMVs on aspirin-treated platelet quantitatively and validate the involvement of several signaling molecules. Biological validation showed that BDMVs increased phospholipase C (PLC), protein kinase C (PKC) and Akt phosphorylation. We also used PLC inhibitor U73122 to treat BDMV-intervened platelet and found reduced phosphorylation of the downstream signaling molecule PKC. These findings suggest that COX-1 within BDMVs may partially counteract the inhibitory effect of aspirin on platelets. Furthermore, BDMVs, combined with arachidonic acid (AA), activate aspirin-treated platelets and suggest the involvement of the PLC/PKC pathway. This study provides a theoretical basis for the early treatment of patients with clinical aspirin-related cerebral hemorrhage.