Liu Xueqing, Yan Yan, Bao Li, Chen Beidong, Zhao Yanyang, Qi Ruomei
The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China.
The Key Laboratory of Geriatrics, Beijing Hospital & Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China.
Thromb Res. 2014 Nov;134(5):1066-73. doi: 10.1016/j.thromres.2014.08.025. Epub 2014 Sep 6.
Atherosclerosis is a chronic vascular inflammatory disease. Platelets play a critic role in the initiation of vascular inflammation in atherosclerosis. In the present study, we investigated the effects of ginkgolide B on the inhibition of platelet release and the potential mechanisms.
Experiments were performed in freshly human platelets. Platelet aggregation and ATP release were measured with a Lumi-aggregometer. Thrombin (0.5 U/ml) was used to induce platelet activation. Protein expression and phosphorylation was examined by Western blotting.
The results showed that ginkgolide B significantly suppressed ATP release by 50.8% in thrombin-activated platelets. Ginkgolide B completely abolished the expression of platelet factor 4 (PF4) and CD40 Ligand (CD40L). Moreover, ginkgolide B fully attenuated the phosphorylation of Syk and p38MAPK. Similarly, R788 (a syk inhibitor) and SB203580 (a p38 MAPK inhibitor) inhibited the expression PF4 and CD40L, respectively. Furthermore, the combination of low concentrations of ginkgolide B and R788 or SB203580 has synergistic inhibition on the expression of PF4 and CD40L. Ginkgolide B partially reduced calcium efflux by 52.7% in thrombin-stimulated platelets.
Ginkgolide B potently inhibited the expression of PF4 and CD40L in thrombin-activated platelets. Ginkgolide B partially decreased ATP release and Ca(2+) efflux. The mechanism might be associated with the inhibition of Syk and p38 MAPK phosphorylation. These results demonstrated that ginkgolide B might be a promising drug on inhibiting platelet function and reducing inflammation in atherosclerosis.
动脉粥样硬化是一种慢性血管炎症性疾病。血小板在动脉粥样硬化血管炎症的起始过程中起关键作用。在本研究中，我们探究了银杏内酯B对抑制血小板释放的作用及其潜在机制。
实验在新鲜人血小板中进行。用全血血小板聚集仪测量血小板聚集和ATP释放。用凝血酶（0.5 U/ml）诱导血小板活化。通过蛋白质印迹法检测蛋白质表达和磷酸化情况。
结果显示，银杏内酯B可使凝血酶激活的血小板中ATP释放显著减少50.8%。银杏内酯B完全消除了血小板因子4（PF4）和CD40配体（CD40L）的表达。此外，银杏内酯B完全减弱了Syk和p38丝裂原活化蛋白激酶（p38MAPK）的磷酸化。同样，R788（一种Syk抑制剂）和SB203580（一种p38 MAPK抑制剂）分别抑制了PF4和CD40L的表达。此外，低浓度的银杏内酯B与R788或SB203580联合使用对PF4和CD40L的表达具有协同抑制作用。银杏内酯B使凝血酶刺激的血小板中钙外流部分减少了52.7%。
银杏内酯B能有效抑制凝血酶激活的血小板中PF4和CD40L的表达。银杏内酯B可部分减少ATP释放和Ca(2+)外流。其机制可能与抑制Syk和p38 MAPK磷酸化有关。这些结果表明，银杏内酯B可能是一种有前景的药物，可用于抑制血小板功能并减轻动脉粥样硬化中的炎症反应。
