Role of glycosaminoglycans (GAGs) in deep vein thrombus formation and resolution

项目摘要 静脉血栓栓塞疾病是心血管疾病死亡的第三大常见原因。 疾病尽管在标准抗凝治疗中增加了导管定向溶栓，但复发性 深静脉血栓形成（DVT）和随后的血栓后综合征（PTS），其中体征和症状 的DVT持续存在或恶化，血栓消退，仍造成长期残疾。更好地理解 深静脉血栓形成和解决的基本机制是必要的。 为了形成DVT，必须发生内皮细胞（EC）损伤。最近，EC糖萼（eGCX）， 糖蛋白、蛋白聚糖和相关糖胺聚糖（GAG）的膜结合网已经出现， 作为能够调节血管舒张、炎症、增殖的多功能表面层， 凝血途径3种最主要的eGCX GAG，硫酸乙酰肝素（HS）、硫酸软骨素（CS）和 透明质酸（HA）与抗凝血酶、肝素辅因子II和非- 循环因子Xi（FXi）。这些关键凝血成分的GAG结合表明， 目前尚不清楚GAG在血栓形成和消退中的作用， 机械调查。 该提案的目标是阐明eGCX调节DVT形成的机制作用， 分辨率我的假设是，受损的eGCX将通过增加血小板EC来促进DVT的形成。 相互作用并通过释放非循环FXI激活内源性凝血途径。而且 受损的eGCX将通过增加炎性（M1）单核细胞浸润到血栓中而损害DVT的消退 和静脉壁。在目标1中，我将确定eGCX GAG在血小板活化和血栓形成中的作用。 在野生型CD 1小鼠中使用腔静脉收缩DVT模型。在目标2中，我将确定eGCX GAG的作用 导致血栓形成后静脉壁改变。这项研究将潜在地确定相关的治疗靶点， 直接影响DVT的形成和解决，为介入研究铺平道路，并支持 开发选择性、安全性和有效的抗血栓药物的基本原理。这些研究报告将 在俄勒冈州的主要学术医疗中心，俄勒冈州健康与科学大学， 生物医学工程系和血管外科系在Monica Hinds博士的共同指导下， PhD和Dr. Khanh Nguyen，MD。PI由资深科学家和医生组成的导师团队提供支持 具有血管病理生理学、血栓形成和血管外科方面的专业知识。职业发展活动 包括小鼠手术、体外和体内分析技术以及凝血和血管 病理生理学，以及沟通和领导技能的培训。该培训旨在支持 PI的职业目标是成为一名医生-科学家，其长期职业目标是领导一个富有成效的 转化血管病理生理学实验室与紧密整合的血管外科实践。

PROJECT SUMMARY Venous thromboembolism disorders represent the third most common cause of death from cardiovascular disease. Despite the addition of catheter directed thrombolysis to standard anticoagulation therapy, recurrent deep vein thrombosis (DVT) and subsequent post-thrombotic-syndrome (PTS), where the signs and symptoms of DVT persist or worsen with thrombus resolution, still cause long term disability. Thus, a better understanding of the basic mechanisms of DVT formation and resolution is needed. In order for a DVT to form, endothelial cell (EC) injury must occur. Recently, the EC glycocalyx (eGCX), a membrane bound mesh of glycoproteins, proteoglycans, and associated glycosaminoglycans (GAGs), has come into focus as a multifunctional surface layer capable of regulating vasodilation, inflammation, proliferation, and coagulation pathways. The 3 most prominent eGCX GAGs, heparan sulfate (HS), chondroitin sulfate (CS), and hyaluronan (HA), have been associated with binding sites for anti-thrombin, heparin cofactor II, and non- circulating factor XI (FXI). GAG binding of these critical coagulation components suggests an ambiguous and currently unclarified role for GAGs in thrombus formation and resolution, warranting further mechanistic investigation. The goal of this proposal is to elucidate the mechanistic role by which the eGCX regulates DVT formation and resolution. My hypothesis maintains that an injured eGCX will bolster DVT formation by increasing platelet-EC interactions and activating the intrinsic clotting pathway, via release of non-circulating FXI. Furthermore, the injured eGCX will impair DVT resolution by increasing inflammatory (M1) monocyte infiltration into the thrombus and the vein wall. In Aim 1, I will determine the role of eGCX GAGs in platelet activation and thrombus formation using a caval constriction DVT model in wildtype CD1 mice. In Aim 2, I will determine the role of eGCX GAGs in causing post-thrombotic vein wall changes. This study will potentially identify relevant therapeutic targets that directly affect DVT formation and resolution, paving the way for interventional studies and supporting the rationale for the development of selective, safe, and effective antithrombotic agents. These studies will be performed at Oregon's primary academic medical center, the Oregon Health and Science University in the Departments of Biomedical Engineering and Vascular Surgery under the co-mentorship of Dr. Monica Hinds, PhD and Dr. Khanh Nguyen, MD. The PI is supported by a mentorship team of senior scientists and physicians with expertise in vascular pathophysiology, thrombosis, and vascular surgery. Career development activities include training in mouse surgery, in vitro and in vivo analysis techniques, and coagulation and vascular pathophysiology, as well as training in communication and leadership skills. This training is designed to support the PI's career goals of becoming a physician-scientist with a long-term career goal of leading a productive and translational vascular pathophysiology laboratory with a tightly integrated vascular surgery practice.