流体剪应力作用下VWF-A1A2A3介导的血小板P-选择素的原位表达

目的 探讨流体剪应力（fluid shear stress, FSS）对VWF-A1A2A3介导的血小板表面P-选择素表达的影响。方法 利用平行平板流动腔实验系统，以CD62P：FITC作为血小板表面P-选择素表达的指示剂，采用荧光显微镜观察分析在不同FSS条件（0、1、2 Pa）下，血小板经由VWF-A1A2A3特异介导黏附后P-选择素表达随时间的变化过程，提取特征参数。结果 FSS扣动了血小板激活并产生P-选择素表达的扳机，激活比率受FSS大小和持续时间的正向调节，在1 Pa和2 Pa时的最高激活比率分别为9.42%和14.59%；P-选择素表达水平随FSS作用时间的延长先提高后降低，呈现一个“双相”的变化过程，最佳作用时间为7.5 min；P-选择素表达的荧光峰值随剪应力的增加而上升。结论 血小板P-选择素表达受FSS和VWF-A1A2A3的协同调控，表达水平与力信号的持续时间相关。
Objective To investigate the effect of fluid shear stress (FSS) on VWF-A1A2A3-mediated expression of platelet surface P-selectin. Methods Using a parallel plate flow chamber system and mouse anti-human CD62P: FITC as the indicator of P-selectin expression, the alteration of platelet P-selectin expression level with increasing exposure time under different FSS conditions (0, 1, 2 Pa) specifically mediated by VWF-A1A2A3 was observed and analyzed by fluorescence microscope to obtain the activation characteristics. Results FSS triggered platelet activation and P-selectin expression. The activation ratio of platelet was positively regulated by FSS and their exposure time, reaching the maximum value, 9.42% and 14.59% under FSS of 1 Pa and 2 Pa, respectively. The level of P-selectin expression exhibited two-phase tendency with the shear stress-exposure time increasing, uplifted at first, then decreased, with the best action time at 7.5 min. The fluorescence peak intensity increased when FSS was enhanced. Conclusions The level of platelet P-selectin expression is co-regulated by VWF-A1A2A3 and FSS, and is closely related to force-signaling exposure time.