LPS enhances platelets aggregation via TLR4, which is related to mitochondria damage caused by intracellular ROS, but not extracellular ROS
LPS enhances platelets aggregation via TLR4, which is related to mitochondria damage caused by intracellular ROS, but not extracellular ROS
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LPS通过TLR4增强血小板聚集，这与细胞内ROS引起的线粒体损伤有关，但与细胞外ROS无关
DOI：
10.1016/j.cellimm.2018.04.002
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发表时间：
2018-06-01
影响因子：
4.3
通讯作者：
Chen, Fangping
中科院分区：
文献类型：
--
作者：
Feng, Guo;Yang, Xinyu;Chen, Fangping
血小板是有助于止血和免疫的重要细胞。细菌脂多糖 (LPS) 主要通过刺激 Toll 样受体 4 (TLR4) 发挥作用，介导血小板活化和败血症。然而，脓毒症中这些参与者之间的相互关系仍然未知。我们发现脓毒症患者全血中的血小板聚集比健康献血者的全血增强。下面的研究使用从健康献血者全血中分离的PRP来滤除不相关细胞的干扰。结果显示，LPS 攻击的 PRP 模型中的最大聚集率 (MAR) 显着高于对照组，并且施用特定的 TLR4 抑制剂 TAK242 降低了该模型中的 MAR。 LPS 促进 P-选择素表达和细胞内 ROS 产生，TAK242 和 N-乙酰基-L-半胱氨酸 (NAC) 均可抑制 LPS 诱导的 P-选择素和细胞内 ROS 增加。 H2O2 给药部分增加了 P-选择素的表达，但对细胞内 ROS 几乎没有影响，认为它增加了线粒体损伤。在体内，与对照组相比，LPS 增加了细胞内 ROS 和 CD62P，而 TAK242 可以阻止这种影响。此外，通过LPS-TLR4途径的血小板聚集参与AKT、PKC和p38磷酸化，但不参与cGMP/cAMP途径。总之，本研究表明，细胞内ROS，而不是细胞外ROS，如H2O2，通过LPS/TLR4途径在促进血小板聚集中发挥着至关重要的作用，并且该过程参与AKT、PKC和p38磷酸化，但不参与cGMP/cAMP途径。该结果有助于理解细胞内ROS和LPS-TLR4通路在血小板聚集中的作用。
Platelet is an important cell contributing to hemostasis and immunity. Bacterial lipopolysaccharide (LPS), mainly functioning by stimulating toll-like receptor 4 (TLR4), mediates platelet activation and sepsis. However, the inter-relationship between these players in sepsis remains unknown. We found that the aggregation of platelets was enhanced in complete blood of sepsis patients than that of healthy donors. PRP isolated from complete blood of healthy donors was used in the following study to filter out the interference of irrelevant cells. The results shown that the maximum aggregation rate (MAR) was significantly higher in LPS-challenged PRP model than that of controls, and administration of the specific TLR4 inhibitor, TAK242, reduced the MAR in this model. LPS promoted P-selectin expression and intracellular ROS production, and both TAK242 and N-acetyl-L-cysteine (NAC) could depressed the LPS-induced increase of P-selectin and intracellular ROS. H2O2 administration increased P-selectin expression partially but had little effect on intracellular ROS, thought it increased mitochondrial damage. In vivo, LPS increased both intracellular ROS and CD62P comparing with that of controls, effects that were prevented by TAK242. Furthermore, platelet aggregation through LPS-TLR4 pathway was involved in AKT, PKC and p38 phosphorylation but not cGMP/cAMP pathway. In conclusion, this study shows that intracellular ROS, not extracellular ROS such as H2O2, plays a crucial role in facilitating platelet aggregation via LPS/TLR4 pathway, and this process was involved in AKT, PKC and p38 phosphorylation but not cGMP/cAMP pathway. The results would helpful for understanding the role of intracellular ROS and LPS-TLR4 pathway in platelet aggregation.