Alpha-Defensins in perioperative thrombosis

围手术期血栓形成中的α-防御素

• 批准号: 8885365
• 负责人: Abd Alroof HIGAZI
• 金额: $ 40万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-02 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8885365
• 关键词: Address; Adherence; Animals; Anticoagulants; Attenuated; Biological Markers; Bone Marrow; Bone Marrow Transplantation; Carotid Arteries; Clinical; Coagulation Process; Colchicine; Complex; Cytolysis; Cytoplasmic Granules; Data; Defensins; Deposition; Disease; Dose; Embolism; Enzymes; Equilibrium; Femoral vein; Fibrin; Fibrinogen; Fibrinolysis; Genetic; Hemorrhage; Hemostatic function; Human; In Vitro; Individual; Infection; Infection prevention; Inflammation; Investigation; Link; Lung; Measures; Mediator of activation protein; Medical; Methods; Modeling; Mus; Natural Immunity; Neutrophil Activation; Operative Surgical Procedures; Oral; Outcome; Patients; Peptides; Perioperative; Permeability; Plasma; Platelet Activation; Play; Populations at Risk; Postoperative Period; Prevention; Prevention Guidelines; Process; Property; Proteins; Publishing; Rattus; Resistance; Risk; Risk Estimate; Risk Factors; Risk Reduction; Role; Scanning Electron Microscopy; Structure; Thromboembolism; Thrombosis; Thrombus; Transgenic Mice; Transplantation; Venous; Venous Thrombosis; Wound Healing; alpha-Defensins; antimicrobial peptide; bariatric surgery; base; biophysical analysis; biophysical techniques; crosslink; effective intervention; in vivo; inhibitor/antagonist; injured; insight; knock-down; man; meetings; neutrophil; novel; novel strategies; polymerization; prevent; prophylactic; public health relevance; reconstitution; research study; small hairpin RNA

 DESCRIPTION (provided by applicant): Surgery increases the risk of thrombosis but prevention and management of thromboembolic disease in the perioperative period is complicated by the risk of hemorrhage. Neutrophils (PMNs) play a vital role in wound healing, but their contribution to perioperative thrombosis and implications for thromboprophylaxis are now emerging. Adherence of PMNs to wounds and to the vasculature generates a unique localized sequestrum enriched in enzymes and antimicrobial peptides protected from plasma inhibitors that contribute to innate immunity in part through the orderly formation and dissolution of fibrin. We posit that post-operative and persistent inflammation disrupt this balance, predisposing to thrombosis by promoting formation and persistence of fibrin. We have previously observed that a-defensins (a-def), antimicrobial peptides that constitute 5% of total human PMN protein that are released upon activation, promote clotting and inhibit fibrinolysis. The absence of a-def in murine PMNs has hindered a better understanding of how these peptides contribute to thromboembolic disease in the perioperative setting. Using a novel transgenic mouse that expresses PMN a-def (Def++), we show that a-def circulates in a complex with fibrinogen and promotes polymerization and retraction of fibrin in vitro, deposits in the vasculature, induces occlusive arterial and venous thrombosis, and inhibits lysis of pulmonary emboli in vivo. These pathogenic properties can be transferred to wild type animals by transplanting bone marrow from Def++ mice and can be prevented and reversed by immunodepleting PMNs or by inhibiting a-def release using colchicine. We now propose an integrated approach to understanding the mechanism and implications of PMN a-def on perioperative thrombosis by examining: a) The biophysical effects of a-def on clot formation and structure; b) The mechanism of accelerated thrombosis and impaired fibrinolysis in Def++ mice and the salutary effect of blocking a-def release; and c) The utility of a-def expression as a biomarker for risk of venous thromboembolism post- surgery. These studies will provide insight into an unappreciated contribution of PMN a-def to arterial and venous thrombosis, identify novel genetic and protein biomarkers of patients at risk for surgery related thrombosis and provide evidence for the use of a safe and effective intervention to prevent thrombosis in the perioperative period.

 描述（由申请人提供）：手术增加了血栓形成的风险，但围手术期血栓栓塞性疾病的预防和管理因出血风险而变得复杂。中性粒细胞（PMNs）在伤口愈合中起着至关重要的作用，但它们对围手术期血栓形成的作用和对血栓预防的意义正在显现。中性粒细胞粘附于伤口和脉管系统产生独特的局部死骨，其富含酶和抗微生物肽，免受血浆抑制剂的保护，这些酶和抗微生物肽通过有序的形成和溶解部分地促进先天免疫 纤维蛋白。我们认为，术后和持续的炎症破坏了这种平衡，通过促进纤维蛋白的形成和持续而诱发血栓形成。我们以前已经观察到，α-防御素（a-def），抗菌肽，占总的人PMN蛋白的5%，激活后释放，促进凝血和抑制纤维蛋白溶解。在小鼠中性粒细胞中缺乏α-def阻碍了更好地理解这些肽如何在围手术期引起血栓栓塞性疾病。使用一种新的转基因小鼠，表达中性粒细胞α-def（Def++），我们表明，α-def循环在一个复杂的纤维蛋白原和促进聚合和收缩的纤维蛋白在体外，沉积在血管系统中，诱导闭塞性动脉和静脉血栓形成，并抑制溶解的肺栓塞在体内。这些致病特性可以通过移植来自Def++小鼠的骨髓转移到野生型动物，并且可以通过免疫耗竭PMN或通过使用秋水仙素抑制a-def释放来预防和逆转。我们现在提出了一个综合的方法来理解PMN的a-def对围手术期血栓形成的机制和意义，通过检查：a）a-def对凝块形成和结构的生物物理作用; B）Def++小鼠中加速血栓形成和受损纤溶的机制以及阻断a-def释放的有益作用;和c）a-def表达作为手术后静脉血栓栓塞风险的生物标志物的效用。这些研究将深入了解PMN a-def对动脉和静脉血栓形成的未被重视的贡献，确定具有手术相关血栓形成风险的患者的新型遗传和蛋白质生物标志物，并为使用安全有效的干预措施预防围手术期血栓形成提供证据。