McVey Mark J, Kim Michael, Tabuchi Arata, Srbely Victoria, Japtok Lukasz, Arenz Christoph, Rotstein Ori, Kleuser Burkhard, Semple John W, Kuebler Wolfgang M
Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada.
Departments of Anesthesia and Physiology, University of Toronto, and Department of Anesthesia and Pain Medicine Sickkids Hospital, Toronto, Ontario, Canada.
Am J Physiol Lung Cell Mol Physiol. 2017 May 1;312(5):L625-L637. doi: 10.1152/ajplung.00317.2016. Epub 2017 Mar 10.
Pulmonary complications from stored blood products are the leading cause of mortality related to transfusion. Transfusion-related acute lung injury is mediated by antibodies or bioactive mediators, yet underlying mechanisms are incompletely understood. Sphingolipids such as ceramide regulate lung injury, and their composition changes as a function of time in stored blood. Here, we tested the hypothesis that aged platelets may induce lung injury via a sphingolipid-mediated mechanism. To assess this hypothesis, a two-hit mouse model was devised. Recipient mice were treated with 2 mg/kg intraperitoneal lipopolysaccharide (priming) 2 h before transfusion of 10 ml/kg stored (1-5 days) platelets treated with or without addition of acid sphingomyelinase inhibitor ARC39 or platelets from acid sphingomyelinase-deficient mice, which both reduce ceramide formation. Transfused mice were examined for signs of pulmonary neutrophil accumulation, endothelial barrier dysfunction, and histological evidence of lung injury. Sphingolipid profiles in stored platelets were analyzed by mass spectrophotometry. Transfusion of aged platelets into primed mice induced characteristic features of lung injury, which increased in severity as a function of storage time. Ceramide accumulated in platelets during storage, but this was attenuated by ARC39 or in acid sphingomyelinase-deficient platelets. Compared with wild-type platelets, transfusion of ARC39-treated or acid sphingomyelinase-deficient aged platelets alleviated lung injury. Aged platelets elicit lung injury in primed recipient mice, which can be alleviated by pharmacological inhibition or genetic deletion of acid sphingomyelinase. Interventions targeting sphingolipid formation represent a promising strategy to increase the safety and longevity of stored blood products.
储存血液制品引起的肺部并发症是输血相关死亡的主要原因。输血相关急性肺损伤由抗体或生物活性介质介导，但其潜在机制尚未完全明确。鞘脂如神经酰胺可调节肺损伤，且其组成会随储存血液的时间而变化。在此，我们检验了衰老血小板可能通过鞘脂介导机制诱导肺损伤的假说。为评估该假说，设计了一种双打击小鼠模型。在输注10 ml/kg储存（1 - 5天）的血小板前2小时，给受体小鼠腹腔注射2 mg/kg脂多糖（预激），所输注的血小板添加或未添加酸性鞘磷脂酶抑制剂ARC39，或来自酸性鞘磷脂酶缺陷小鼠的血小板，这两种情况均可减少神经酰胺的形成。对输注后的小鼠进行检查，观察肺部中性粒细胞聚集、内皮屏障功能障碍的迹象以及肺损伤的组织学证据。通过质谱分析法分析储存血小板中的鞘脂谱。将衰老血小板输注到预激小鼠体内可诱导肺损伤的特征性表现，且损伤严重程度随储存时间增加。储存过程中血小板内神经酰胺会蓄积，但ARC39或在酸性鞘磷脂酶缺陷的血小板中这种蓄积会减弱。与野生型血小板相比，输注ARC39处理的或酸性鞘磷脂酶缺陷的衰老血小板可减轻肺损伤。衰老血小板在预激的受体小鼠中引发肺损伤，通过药理学抑制或基因敲除酸性鞘磷脂酶可减轻这种损伤。针对鞘脂形成的干预措施是提高储存血液制品安全性和延长其保存期限的一种有前景的策略。
