Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran; Australian Centre for Blood Diseases, Monash University, Melbourne, Victoria 3004, Australia.
Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran.
Thromb Res. 2018 Mar;163:153-161. doi: 10.1016/j.thromres.2018.01.048. Epub 2018 Feb 1.
Platelets storage lesion is mainly orchestrated by platelet activating signals during storage. Reactive oxygen species (ROS) are being considered as important signaling molecules modulating platelet function while their production has also been shown to be augmented by platelet activation. This study investigated to what extent endogenous ROS generation during platelet storage could be correlated with platelet receptor shedding, microvesiculation and adhesive function. 10 PRP-platelet concentrates were subjected to flow cytometry analysis to examine the generation of intraplatelet ROS on days 1, 5 and 7 after storage. In 5 day-stored platelets considering 40% of ROS generation as a cutoff point, samples were divided into two groups of those with higher or lower levels of ROS. The expression of adhesion receptors (GPVI, GPIbα), the amount of microparticles and phosphatidylserine exposure in each group were then examined by flow cytometry. Platelet receptor shedding and adhesion to collagen matrix were respectively measured by western blotting and microscopic assays. Our data showed lowered expression of GPIbα (p < 0.05) and GPVI in samples with ROS > 40% than those with ROS ≤ 40%, whereas receptors shedding and microvesiculation were (p < 0.05) elevated in platelets with higher levels of ROS. Functionally, we observed significantly (p < 0.05) lower levels of platelet adhesion to collagen matrix in samples with ROS generation more than 40%. Taken together, we showed correlations between intraplatelet ROS generation and either platelet receptors or microparticle shedding as well as platelet adhesive capacity to collagen. These findings suggest that augmented ROS generation during storage might be relevant to down-regulation of platelet adhesive function.
血小板储存损伤主要由储存过程中的血小板激活信号调控。活性氧(ROS)被认为是调节血小板功能的重要信号分子,但其产生也被证明可被血小板激活所增强。本研究旨在探讨血小板储存过程中内源性 ROS 生成与血小板受体脱落、微泡形成和黏附功能之间的相关性。将 10 份富含血小板的血浆(PRP)血小板浓缩物进行流式细胞术分析,以检测储存后第 1、5 和 7 天血小板内 ROS 的生成情况。在储存 5 天的血小板中,将 40%的 ROS 生成作为临界点,将样本分为 ROS 生成水平较高和较低的两组。然后通过流式细胞术检测两组的黏附受体(GPVI、GPIbα)表达、微颗粒数量和血小板膜磷脂酰丝氨酸暴露情况。通过 Western blot 和显微镜检测分别测量血小板受体脱落和黏附到胶原基质的情况。我们的数据显示,ROS>40%的样本中 GPIbα(p<0.05)和 GPVI 的表达水平降低,而 ROS 水平较高的血小板中受体脱落和微泡形成增加(p<0.05)。功能上,我们观察到 ROS 生成超过 40%的样本中血小板黏附到胶原基质的水平显著降低(p<0.05)。总之,我们发现血小板内 ROS 生成与血小板受体或微颗粒脱落以及血小板黏附到胶原的能力之间存在相关性。这些发现表明储存过程中 ROS 生成增加可能与血小板黏附功能下调有关。