Modulating Fibrinolysis Dynamics by Leveraging Multivalent Avidity to Control Enzyme Activity

通过利用多价亲和力控制酶活性来调节纤维蛋白溶解动力学

• 批准号: 10635496
• 负责人: Nathan J Alves
• 金额: $ 47.26万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10635496
• 关键词: Active Sites; Acute; Address; Affect; Affinity; Alteplase; Antiplasmin; Avidity; Binding; Binding Proteins; Biological Assay; Blood Vessels; Blood coagulation; Bypass; Catheters; Characteristics; Clinic; Coagulation Process; Complex; Cytolysis; Data; Deep Vein Thrombosis; Diagnosis; Digestion; Enzyme Inhibition; Enzyme-Linked Immunosorbent Assay; Enzymes; Fibrin; Fibrinolysis; Fibrinolytic Agents; Future; Goals; Hemorrhage; Hemostatic function; Homo; Human; In Vitro; Infusion procedures; Injury; Intervention; Intracranial Hemorrhages; Ischemic Stroke; Knowledge; Kringles; Label; Lead; Length; Link; Molecular; Myocardial Infarction; Pathogenicity; Patients; Persons; Pharmacologic Substance; Plasmin; Plasmin Inhibitor; Plasminogen; Predictive Factor; Proteins; Pulmonary Embolism; Recurrence; Research; Risk; Safety; Scheme; Serpins; Standardization; Surface; System; Therapeutic; Therapeutic Intervention; Thermodynamics; Thrombolytic Therapy; Time; Translating; Translations; Whole Blood; active control; alpha 2-Glucoproteins; clinical translation; enzyme activity; enzyme substrate; experimental study; genetic regulatory protein; improved; in vivo; inhibitor; limb ischemia; mouse model; nanoparticle; novel; novel strategies; standard of care; translational potential; venous thromboembolism

PROJECT SUMMARY Blood clots kill more humans than any other single pathogenic cause. A new or recurrent diagnosis of venous thromboembolism (VTE), which encompasses both pulmonary embolism (PE) and deep vein thrombosis (DVT), affects >900,000 people each year in the US alone. Current PE standard of care includes the delivery of acute clot digesting enzymes such as recombinant tissue Plasminogen Activator (tPA), administered IV or by catheter. All currently FDA cleared clot digesting enzymes rely on activation of the patient’s endogenous plasminogen converting nearly all of it to active clot digesting plasmin. This widespread activation massively depletes plasmin regulatory proteins, causing unchecked digestion of both pathogenic and beneficial blood clots resulting in a 5-10% rate of major bleeding complications, including intracranial hemorrhage. Due to safety concerns and contraindications nearly 50% of patients that would benefit from active clot digesting interventions are not eligible to receive the current therapy. Direct infusion of exogenous active plasmin to digest blood clots is limited due to the nearly instantaneous inactivation by circulating α2-antiplasmin (serpin protein) and α2-macroglobulin (steric inhibitor). To address the current limitations of plasmin infusion as a direct fibrinolytic therapeutic intervention, a novel clot digesting delivery strategy leveraging multivalent enzymatic control is necessary. Preliminary data demonstrates that reversible competitive inhibitors can be used to deliver active plasmin with reduced inactivation from regulatory proteins in-vitro while still allowing efficient clot digestion; however, there is critical need to determine the underlying characteristics responsible for protection and delivery of plasmin as a direct fibrinolytic in-vivo. This proposal will identify critical relationships that contribute to multivalent control of active enzymes in-vivo for the novel clinical translation of therapeutic interventions to digest blood clots with an improved safety profile. Aim 1: Determine how homo- and hetero-multivalent inhibitors impact inhibition of plasmin and its interactions with regulatory proteins in- vitro; Aim 2: Evaluate the impact of reversible multivalent enzyme inhibition on clot digestion efficiency of standardized ex-vivo blood clots under shear; and, Aim 3: Examine the impact of multivalent inhibitor delivered plasmin on clot targeting and digestion in-vivo. Overall, these experiments will identify key multivalent enzyme delivery principles and provide lead compounds to be further developed. A safer direct fibrinolytic therapeutic will have expanded indications for use that include: ischemic stroke, myocardial infarction, limb ischemia, PE, DVT, and occluded vascular catheters.

项目概要 血栓导致的死亡人数比任何其他单一致病原因都多。新的或复发的静脉诊断 血栓栓塞 (VTE)，包括肺栓塞 (PE) 和深静脉血栓形成 (DVT)，仅在美国每年就影响超过 900,000 人。当前的 PE 护理标准包括分娩 急性凝块消化酶，例如重组组织纤溶酶原激活剂 (tPA)，静脉注射或 通过导管。目前 FDA 批准的所有凝块消化酶都依赖于患者内源性的激活 纤溶酶原几乎将其全部转化为活性凝块消化纤溶酶。这种广泛的激活大规模 消耗纤溶酶调节蛋白，导致致病性和有益血液的不受控制的消化 血栓导致 5-10% 的严重出血并发症，包括颅内出血。由于 安全问题和禁忌症 近 50% 的患者将从主动血栓消化中受益 干预措施不符合接受当前治疗的条件。直接输注外源性活性纤溶酶 由于循环中的 α2-抗纤溶酶（丝氨酸蛋白酶抑制剂）几乎瞬时失活，消化血凝块受到限制。 蛋白质）和 α2-巨球蛋白（空间抑制剂）。解决目前纤溶酶输注的局限性 直接纤溶治疗干预，一种利用多价的新型凝块消化递送策略 酶控制是必要的。初步数据表明可逆竞争性抑制剂可以 用于递送活性纤溶酶，减少体外调节蛋白的失活，同时仍然允许 高效的凝块消化；然而，迫切需要确定造成这种情况的根本特征 用于保护和递送纤溶酶作为体内直接纤溶剂。该提案将确定关键 有助于体内活性酶多价控制的关系，以实现新的临床转化 消化血栓的治疗干预措施具有改进的安全性。目标 1：确定如何同质化 和异多价抑制剂影响纤溶酶的抑制及其与调节蛋白的相互作用 体外；目标 2：评估可逆多价酶抑制对凝块消化效率的影响 剪切下的标准化离体血凝块；目标 3：检查多价抑制剂的影响 在体内凝块靶向和消化上递送纤溶酶。总的来说，这些实验将确定关键 多价酶递送原理并提供了有待进一步开发的先导化合物。更安全的直达 纤溶治疗将扩大使用适应症，包括：缺血性中风、心肌病 梗塞、肢体缺血、PE、DVT 和血管导管闭塞。