PDI inhibition to prevent thrombosis in humans

项目总结(见说明)： 血栓性疾病的治疗依赖于对血小板或凝血因子的药物靶向。蛋白二硫键异构酶(PDI)由血小板和内皮细胞激活后分泌，定位于膜表面。鉴于PDI在体内调节血小板聚集和纤维蛋白生成方面的作用，我们建议评估PDI作为抗血栓靶点。最近，高通量化合物筛选发现，槲皮素-3-芦丁糖苷和相关的黄酮类化合物是体外PDI氧化还原酶活性和体内几种动物模型血栓形成的有效抑制物。 几项大型流行病学研究表明，富含槲皮素的饮食可以减少人类的心血管事件。鉴于槲皮素是一种广泛使用的营养补充剂，本项目的目的是研究在高凝状态下的抗血栓活性，以此作为验证PDI作为药理靶点的手段。本项目的具体目的是：(1)评价与抗坏血酸联合使用的槲皮素或异槲皮素的药代动力学和药效学，以及研究在以内皮激活(即抗磷脂抗体)为特征的血栓形成状态下，槲皮素是否能降低d-二聚体水平；(2)确定槲皮素是否能预防高循环组织因子患者(即癌症患者)的血栓形成；以及(3)研究是否可以预防血栓形成。 一种以病理性血小板激活为特征的疾病的血栓并发症(即肝素引起的血小板减少伴血栓形成)。通过在这些不同的高凝条件下研究槲皮素，我们的目标是将最近的实验室观察直接转化为后期临床试验。

PROJECT SUMMARY (See instructions): The management of thrombotic disorders relies on the pharmacological targeting of either platelets or clotting factors. Protein disulfide isomerase (PDI) is secreted by platelets and endothelial cells following activation and localizes to the membrane surface. Given the role of PDI in regulating both platelet accumulation and fibrin generation in vivo, we propose to evaluate PDI as an antithrombotic target. A high throughput compound screen recently identified quercetin-3-rutinoside and related flavonoids as potent inhibitors of PDI oxidoreductase activity in vitro and thrombosis formation in vivo in several animal models. Several large epidemiologic studies have shown that quercetin-rich diets reduce cardiovascular events in humans. Considering that quercetin is a widely available nutritional supplement, the goal of this project is to investigate the antithrombotic activity of quercetin in hypercoagulable conditions as a means of validating PDI as a pharmacologic target. The specific aims of this project are (1) to evaluate pharmacokinetics and pharmacodynamics of quercetin or isoquercetin with ascorbic acid as well as to investigate whether quercetin is reduces d-dimer levels in thrombotic condition characterized by endothelial activation (i.e. antiphospholipid antibodies); (2) to determine if quercetin prevents thrombosis in patients with high circulating tissue factor (i.e. cancer patients); and lastly, (3) to investigate whether quercetin can prevent thrombotic complications in a disorder characterized by pathologic platelet activation (i.e. heparin induced thrombocytopenia with thrombosis). By investigating quercetin in these different hypercoagulable conditions, we aim to translate recent laboratory observations directly into later stage clinical trials.