Popis: |
Platelets play a crucial role on hemostasis and are also involved in cardiovascular diseases, such as heart attack and stroke. Artesunate has been reported to possess multiple biological activities, including antitumor and anti-inflammatory activities. However, its effect on platelet activation remains unclear. Thus, we explored the detailed mechanisms underlying its antiplatelet effect. For the in vitro study, the data indicated that artesunate inhibited platelet aggregation induced by collagen, but not thrombin or U46619, indicating that artesunate may selectively inhibit collagen-mediated platelet activation Artesunate also blocked glycoprotein VI (GPVI) downstream signaling, including Syk, PLCγ2, PKC, Akt, and MAPKs. Moreover, artesunate could compete with collagen for binding to collagen receptor and bind to human recombinant GPVI with a high affinity (KD = 44 nM), indicating that it may directly interfere with GPVI. Artesunate also reduced collagen-induced granule release, calcium mobilization, and GPIIbIIIa activation. For the in vivo study, artesunate markedly prevented pulmonary thrombosis and delayed platelet thrombus formation in mesenteric veins and arteries but had minimal effects on hemostasis. In conclusion, we for the first time demonstrated that artesunate acts as a GPVI antagonist and effectively prevents platelet activation and thrombus formation with minimal risk of bleeding, highlighting its therapeutic potential in cardiovascular diseases. |