银杏内酯B抑制血小板CD40Ligand表达的分子机制研究

目的探讨银杏内酯B(ginkgolide B)对活化血小板CD40 Ligand(CD40L)的影响以及相关的分子机制。方法取正常人血分离血小板,用不同浓度银杏内酯B孵育血小板5 min,然后用胶原(collagen)刺激血小板活化。用Westernblot分析PI3K表达,Akt磷酸化,CD40L的变化。结果①用collagen刺激血小板聚集,银杏内酯B(0.2、0.4、0.6 g.L-1)预处理血小板5 min,血小板聚集率明显降低,聚集率分别为77%,60%和48%。②Western blot结果显示胶原刺激血小板活化后CD40L表达明显增加,银杏内酯B以剂量依赖方式抑制了CD40L表达。③银杏内酯B对胶原刺激的血小板PI3K表达无明显影响。④collagen刺激血小板活化后Akt的磷酸化增加,银杏内酯B抑制了Akt磷酸化。结论银杏内酯B能够有效抑制collagen诱导的血小板聚集以及CD40L的表达,并明显抑制了Akt磷酸化,表明银杏内酯B能够通过PI3K/Akt信号传导通路抑制血小板活化。

Inhibitory effects of ginkgolide B on CD40 Ligand expression in collagen-induced platelet activation

Aim To investigate the effects of ginkgolide B on the CD40Ligand(CD40L) expression in collagen-induced platelet activation and the related mechanism.Methods Anti-coagulated blood was collected from health donor.Platelets were isolated through centrifugation.Platelets were pre-incubated by the various concentrations of ginkgolide B for 5 min,then platelets were stimulated by collagen.Protein expression was detected by Western blot.Results 1.10 mg·L-1 of collagen induced platelet aggregation,and 0.2 g·L-1,0.4 g·L-1 and 0.6 g·L-1 of ginkgolide B potently inhibited platelet aggregation in a dose-dependent manner.2.The expression of CD40L was increased in collagen-induced platelet activation.Ginkgolide B significantly attenuated the increase of CD40L expression in activated platelets.3.Ginkgolide B had no effect on PI3K expression in collagen-induced platelet activation.4.Ginkgolide B obviously abolished Akt phosphorylation in activated platelets.Conclusions Ginkgolide B can effectively inhibit the platelet aggregation and CD40L expression in collagen-induced platelet activation.Ginkgolide B significantly decreases Akt phosphorylation.These findings suggest that the effect of ginkgolide B on inhibition of CD40 expression is associated with PI3K/Akt pathway.