School of Pharmacy, University of Reading, Reading RG6 6UB, UK.
Mediators Inflamm. 2017;2017:9605894. doi: 10.1155/2017/9605894. Epub 2017 Oct 17.
Platelets are anucleated blood cells that participate in a wide range of physiological and pathological functions. Their major role is mediating haemostasis and thrombosis. In addition to these classic functions, platelets have emerged as important players in the innate immune system. In particular, they interact with leukocytes, secrete pro- and anti-inflammatory factors, and express a wide range of inflammatory receptors including Toll-like receptors (TLRs), for example, Toll-like receptor 4 (TLR4). TLR4, which is the most extensively studied TLR in nucleated cells, recognises lipopolysaccharides (LPS) that are compounds of the outer surface of Gram-negative bacteria. Unlike other TLRs, TLR4 is able to signal through both the MyD88-dependent and MyD88-independent signalling pathways. Notably, despite both pathways culminating in the activation of transcription factors, TLR4 has a prominent functional impact on platelet activity, haemostasis, and thrombosis. In this review, we summarise the current knowledge on TLR4 signalling in platelets, critically discuss its impact on platelet function, and highlight the open questions in this area.
血小板是无核的血细胞，参与广泛的生理和病理功能。它们的主要作用是调节止血和血栓形成。除了这些经典功能外，血小板已成为先天免疫系统的重要参与者。特别是，它们与白细胞相互作用，分泌促炎和抗炎因子，并表达广泛的炎症受体，包括 Toll 样受体（TLR），例如 Toll 样受体 4（TLR4）。TLR4 是核细胞中研究最广泛的 TLR，可识别革兰氏阴性细菌外表面的脂多糖（LPS）化合物。与其他 TLR 不同，TLR4 能够通过 MyD88 依赖性和 MyD88 非依赖性信号通路进行信号传递。值得注意的是，尽管两条信号通路都最终导致转录因子的激活，但 TLR4 对血小板活性、止血和血栓形成有显著的功能影响。在这篇综述中，我们总结了目前关于血小板中 TLR4 信号的知识，批判性地讨论了它对血小板功能的影响，并强调了该领域的悬而未决的问题。
