国家自然科学(11432006,11672109,11272125,31170887)通信作者: 吴建华,教授,Tel: 020-39380608,E-mail: firstname.lastname@example.org
Institute of Biomechanics,School of Bioscience and Bioengineering,South China University of Technology
The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
目的 在流体剪切力条件下,探究力学微环境对嗜中性粒细胞在活化血小板上滚动黏附的影响。方法 实验在平行平板流动腔中进行。流动腔底板通过吸附vWF-A1而功能化,黏附于功能化底板的血小板通过灌注PBS施加10 dyn/cm2的壁面流体剪切力刺激,力学刺激时间分别为0.0、2.5和7.5 min。利用高速摄像机观察和记录在0.5 dyn/cm2剪切力条件下白细胞在活化血小板上的滚动黏附行为,提取黏附事件数、细胞拴缚停留时间及滚动速度等参数。结果 中性粒细胞能特异性的结合到vWF-A1介导的稳定黏附于流动腔底部的血小板之上；白细胞在血小板上的拴缚停留时间不依赖于力学刺激,但力学刺激会显著促进白细胞在血小板上的黏附,降低白细胞在血小板上的滚动速度。结论 力学刺激血小板将显著提高血小板捕获循环白细胞的能力,促进白细胞在血小板上的滚动黏附。
Objective To investigate effects of wall shear stress on rolling adhesion of neutrophils on immobilized platelets under flows. Methods Experiments were performed with the parallel plate flow chamber technology. Platelets was adhered to the functionalized flow chamber bottom which had been coated with vWF-A1 first, and then was washed with PBS under wall shear stress of 10 dyn/cm2 for different time (0 min, 2.5 min, 7.5 min). A high-speed camera was used to observe and record the rolling adhesion events of neutrophils on immobilized platelets under wall shear stress of 0.5 dyn/cm2, and the adhesion parameters such as the number of adhesion events, the tether lifetime of cells, and rolling velocity. Results Neutrophils can specifically bind to the immobilized platelets on vWF-A1-coated bottom of the flow chamber. Preloading of wall shear stress on the immobilized platelets has no effects on the tether lifetime of neutrophils on the platelets, but up-regulates the adhesive ratio of neutrophils on the platelets and makes the rolling of neutrophils on the platelets slow down. Conclusions Preloading of wall shear stress on the immobilized platelets will significantly make the circulating neutrophils to be captured easily and promote the rolling adhesion of neutrophils on platelets.