Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China.
Bloodworks Research Institute, Seattle, WA.
Blood. 2021 Dec 23;138(25):2714-2726. doi: 10.1182/blood.2021011310.
Severe traumatic brain injury (TBI) often causes an acute systemic hypercoagulable state that rapidly develops into consumptive coagulopathy. We have recently demonstrated that TBI-induced coagulopathy (TBI-IC) is initiated and disseminated by brain-derived extracellular vesicles (BDEVs) and propagated by extracellular vesicles (EVs) from endothelial cells and platelets. Here, we present results from a study designed to test the hypothesis that anticoagulation targeting anionic phospholipid-expressing EVs prevents TBI-IC and improves the outcomes of mice subjected to severe TBI. We evaluated the effects of a fusion protein (ANV-6L15) for improving the outcomes of TBI in mouse models combined with in vitro experiments. ANV-6L15 combines the phosphatidylserine (PS)-binding annexin V (ANV) with a peptide anticoagulant modified to preferentially target extrinsic coagulation. We found that ANV-6L15 reduced intracranial hematoma by 70.2%, improved neurological function, and reduced death by 56.8% in mice subjected to fluid percussion injury at 1.9 atm. It protected the TBI mice by preventing vascular leakage, tissue edema, and the TBI-induced hypercoagulable state. We further showed that the extrinsic tenase complex was formed on the surfaces of circulating EVs, with the highest level found on BDEVs. The phospholipidomic analysis detected the highest levels of PS on BDEVs, as compared with EVs from endothelial cells and platelets (79.1, 15.2, and 3.5 nM/mg of protein, respectively). These findings demonstrate that TBI-IC results from a trauma-induced hypercoagulable state and may be treated by anticoagulation targeting on the anionic phospholipid-expressing membrane of EVs from the brain and other cells.
严重创伤性脑损伤（TBI）常导致急性全身性高凝状态，迅速发展为消耗性凝血病。我们最近证明，TBI 诱导的凝血病（TBI-IC）是由脑源性细胞外囊泡（BDEVs）引发和传播的，由内皮细胞和血小板来源的细胞外囊泡（EVs）传播。在这里，我们介绍了一项旨在检验以下假设的研究结果，即针对表达阴离子磷脂的 EV 进行抗凝治疗可预防 TBI-IC 并改善严重 TBI 小鼠的预后。我们评估了融合蛋白（ANV-6L15）在结合体外实验的情况下改善 TBI 预后的效果。ANV-6L15 将结合 PS 的膜联蛋白 V（ANV）与一种肽类抗凝剂结合，该抗凝剂经过修饰，可优先靶向外源性凝血。我们发现，在 1.9 大气压的流体冲击损伤模型中，ANV-6L15 可使颅内血肿减少 70.2%，神经功能改善，并使死亡率降低 56.8%。它通过防止血管渗漏、组织水肿和 TBI 诱导的高凝状态来保护 TBI 小鼠。我们进一步表明，外源性凝血酶原复合物形成于循环 EV 的表面，其中 BDEVs 上的复合物最多。磷脂组学分析发现 BDEVs 上 PS 的水平最高，而内皮细胞和血小板来源的 EVs 上的 PS 水平分别为 79.1、15.2 和 3.5 nM/mg 蛋白。这些发现表明，TBI-IC 是由创伤引起的高凝状态引起的，可通过针对脑和其他细胞来源的 EV 上表达阴离子磷脂的膜进行抗凝治疗来治疗。
