Thromboregulation in Occlusive Vascular Diseases

描述（由申请人提供）：中风和冠状动脉疾病（CAD）的发病率和死亡率可能是美国最严重的公共卫生问题。缺血性中风和冠状动脉闭塞都是动脉粥样硬化和炎症的并发症，最终导致血小板活化、募集和血管闭塞--这是对血液流动性控制的破坏。由于缺乏新的方法，卒中和CAD治疗方式的进展已达到平台期。本提案的广泛、长期目标和具体目的是通过本文所述的体外和离体研究使胞外酶CD 39/NTPDase 1获得临床成果。我们最近对CD 39的研究表明，它构成了血液流动性（血栓调节）的主要控制系统。CD 39具有独特的作用模式，从而抑制血小板活化和募集，在流体相中起作用。这通过血栓前ADP的代谢缺失发生，ADP是血小板诱导的血管闭塞中的最终共同介质。因此，CD 39的作用机制与目前用于治疗中风和CAD的治疗方式完全不同。如先前发表的，我们在3种动物模型中用可溶性形式的CD 39（solCD 39）成功治疗中风，表明其安全性和有效性。大量的初步分子生物学数据表明，不同的CD 39选择性剪接变体的表达调节CD 39的表达，组装成富含胆固醇的结构域，以及酶和生物活性。这增强了我们对酶的作用机制及其调节的理解。将在隐源性和动脉粥样硬化血栓性卒中患者中研究CD 39。因此，我们将评估正常人和隐源性和动脉粥样硬化血栓性中风患者中CD 39变体表达的概况。在我们的隐源性和动脉粥样硬化血栓形成患者和对照组中，将使用一系列血小板激动剂和凝血参数（包括循环组织因子），在其用药状态下评价血小板反应性和血小板活化标志物。这还包括白细胞-血小板聚集体（重点是单核细胞-血小板聚集体）和血管细胞衍生微粒的表征。我们预计，我们的研究将提供新的治疗机会，CD 39在预防和管理中风和CAD。在这项申请中，我们已经开发了一个临界质量的患者和研究人员，以进一步了解血小板驱动的心血管疾病的发病机制和治疗，并开发CD 39作为下一代抗血栓药物的原型。因此，本次修订申报是一项基础广泛的多学科、分子和临床重点申请。公共卫生相关性：脑血管闭塞（中风）是由过度的血小板反应性和募集引起的，导致广泛的发病率和死亡率。这种反应性可以被酶CD 39中和。这项研究的相关性在于，它提供了一种新的和安全的方法来管理中风，没有令人满意的治疗。我们预期本文提出的研究将导致制定人可溶性腺苷三磷酸双磷酸酶如solCD 39的临床试验。

DESCRIPTION (provided by applicant): Morbidity and mortality from stroke and coronary artery disease (CAD) are probably the most critical public health problems in the US. Both ischemic stroke and coronary occlusion are complications of atherosclerosis and inflammation which culminate in platelet activation, recruitment and vascular occlusion - a breach of the control of blood fluidity. Advances in therapeutic modalities for stroke and CAD have reached a plateau with an absence of novel approaches. The broad, long term objectives and specific aims of this proposal are to bring the ecto-enzyme CD39/NTPDase1 to clinical fruition via the in vitro and ex vivo studies described herein. Our recent studies of CD39 have demonstrated that it constitutes the main control system for blood fluidity (thromboregulation). CD39 has a unique mode of action whereby it inhibits platelet activation and recruitment, acting in the fluid phase. This occurs via metabolic deletion of prothrombotic ADP, the final common mediator in platelet-induced vascular occlusion. Thus the mechanism of action of CD39 is radically different from currently available therapeutic modalities for treatment of stroke and CAD. Our successful treatment of stroke with the soluble form of CD39 (solCD39) in 3 animal models, as previously published, suggests its safety and efficacy. Extensive preliminary molecular biology data indicate that expression of different CD39 alternative splice variants regulates CD39 expression, assembly into cholesterol-rich domains, and enzymatic and biological activity. This enhances our comprehension of the mechanisms of action of the enzyme, and its regulation. CD39 will be studied in cryptogenic and atherothrombotic stroke patients. Thus, we will evaluate the profile of CD39 variant expression in normals and patients with cryptogenic and atherothrombotic stroke. Platelet reactivity and markers of platelet activation will be evaluated in our cryptogenic and atherothrombotic patients and controls using a spectrum of platelet agonists and coagulation parameters, including circulating tissue factor, in the setting of their medication status. This also includes characterization of leukocyte-platelet aggregates (with emphasis on monocyte-platelet aggregates) and vascular cell-derived microparticles. We anticipate that our research will afford novel therapeutic opportunities for CD39 in prophylaxis and management of stroke and CAD. In this application we have developed a critical mass of patients and investigators in order to further our comprehension of the pathogenesis and treatment of platelet-driven cardiovascular diseases and to develop CD39 as the prototype of the next generation of antithrombotic agents. Thus, this revised submission is a broadly based multidisciplinary, molecularly and clinically focused application. PUBLIC HEALTH RELEVANCE: Vascular occlusion in the brain (stroke) is initiated by excessive blood platelet reactivity and recruitment, leading to extensive morbidity and mortality. This reactivity can be neutralized by the enzyme CD39. The relevance of this research is that it is provides a new and safe approach to the management of stroke for which there is no satisfactory treatment. We anticipate that the research proposed herein will lead to formulation of a clinical trial of a human soluble apyrase such as solCD39.