线粒体对血小板凋亡和活化的调控作用

Regulation of Mitochondria on Platelet Apoptosis and Activation

目的:探讨线粒体对血小板凋亡和活化的调控作用,以及血小板凋亡和活化的关系。方法:从健康志愿者外周静脉血中分离血小板,选择对血小板线粒体功能具有保护作用的环孢菌素A、可穿膜螯合血小板内钙离子的BAPTA、降低细胞内活性氧水平的抗氧化剂NAC分别与洗涤血小板共同孵育,借助流式细胞术、血小板聚集仪检测不同干预后血小板线粒体功能的变化和血小板活化指标的改变。结果:蛋白激酶抑制剂H89、星形孢菌素、钙离子载体A23187导致血小板线粒体异常,而环孢菌素A有效逆转了其引起的血小板线粒体膜电位的下降。NAC相应地可以逆转血小板线粒体损伤,完全逆转H89诱导的血小板皱缩和磷脂酰丝氨酸外翻。BAPTA、前列腺素E1、乙酰水杨酸等抑制剂都不会逆转血小板线粒体膜电位下降的现象。结论:线粒体功能对血小板凋亡和活化具有重要影响,线粒体功能异常引起血小板内氧化还原状态失衡,从而导致血小板发生凋亡,血小板发生凋亡和活化是各自独立的信号过程。

Objective: To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation. Methods: Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A(CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for co-incubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions. Results: H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential. Conclusion: Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.