Recombinant annexin A2 plus tPA for combination stroke therapy

重组膜联蛋白 A2 加 tPA 用于中风联合治疗

基本信息

批准号：
8103811
负责人：
XIAOYING WANG
金额：
$ 37.28万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8103811
关键词：
ANXA2 gene Adhesives Adverse effects Aftercare Angiogenic Factor Angiography Attenuated Biological Assay Biological Markers Blood - brain barrier anatomy Blood Vessels Blood Volume Blood flow Brain Brain Infarction Cerebral Ischemia Cerebrovascular Circulation Cerebrum Coagulation Process Collagen Type IV Combined Modality Therapy Complex Core-Binding Factor Critical Care Cytolysis Data Development Diffusion Dose Edema Emergency treatment Enzymes Evans blue stain Evolution Excision Extracellular Matrix Degradation Extravasation FDA approved Fibrin fragment D Fibrin split products Fibrinolytic Agents Gel Gelatinase B Generations Hematoxylin and Eosin Staining Method Hemorrhage Hypercapnia Hyperoxia In Situ Infarction Infiltration Inflammation Injury Intervention Ischemic Stroke Laminin Lead Lesion Magnetic Resonance Imaging Maps Measurement Measures Mediating Microglia Molecular Myelin Basic Proteins Neurological outcome Outcome Patients Perfusion Plasma Plasmin Plasminogen Proteins Proteolysis Rattus Recombinants Recovery Relative (related person)Reperfusion Therapy Risk Saline Stroke Testing Therapeutic Tight Junctions Time Tissues Translating Translational Research Vascular Endothelial Growth Factors Vasodilator Agents Western Blotting base behavior test brain tissue claudin-1 protein density functional outcomes hemodynamics improved indexing insight intravenous administration mortality multidisciplinary neurotoxicity novel public health relevance research study response stroke therapy thrombolysis vasoconstriction white matter

项目摘要

DESCRIPTION (provided by applicant): Intravenous administration of recombinant tPA remains the only FDA-approved and the most beneficial proven intervention for emergency treatment of stroke. However, short treatment time window, hemorrhagic transformation, poor thrombolytic perfusion rate, and neurotoxicity comprise the major limitations to the application. In this proposal, we hypothesize that recombinant Annexin A2 protein (rA2) will lower the required dose of tPA for reperfusion, while enhancing thrombolytic efficacy, and attenuating intracerebral hemorrhagic transformation. By doing so, it will prolong therapeutic time windows and improve long-term outcomes. The molecular basis for our idea is that annexin A2 accelerates the generation of clot-dissolving plasmin by assembling a fibrinolytic complex with tPA and the plasmin precursor plasminogen. Our pilot data are promising. We now propose three aims to investigate the mechanisms involved in this new combination therapy. In Aim 1, we will study thrombolytic efficacy of rA2 plus low dose tPA combination treated at 4 hrs after focal embolic stroke in rats with MR angiography to determine recanalization and reocclusion, MRI CBF to map cerebral blood flow; and MRI measurements of cerebral blood volume (CBV), microvascular volume (MVV), and vessel size index (VSI) to quantify vascular responses to thrombolytic agents and vasodilators. In Aim 2, we will investigate effects of rA2 plus low dose tPA combination therapy on neurovascular matrix proteolysis and BBB leakage treated at 4 hrs after focal embolic stroke of rats. The development of brain infarction, edema and hemorrhagic transformation will be measured and correlated with temporal profiles of MMP-9 activity, proteolytic degradation of extracellular matrix components and BBB leakage. In Aim 3, we will assess long term outcomes of rA2 plus low dose tPA combination treated at 4 hrs after stroke. Rats will be followed over 4 weeks with a battery of behavioral tests. At the end, brains are removed for H&E lesion size measurement, cerebral vessel density and tissue recovery factors VEGF, Ang-1 expression will be examined. Low-dose tPA plus rA2 will be compared with rA2 alone, low-dose and high-dose tPA alone, and vehicle saline control. If successful, these proposed experiments should provide new insight of how rA2 plus low dose tPA improve tPA stroke treatment and may ultimately yield a novel combination approach to optimize tPA-based thrombolytic stroke therapy. We believe our proposal should be directly relevant for PA-07-233, "Multidisciplinary Translational Research in Critical Care" (R01). PUBLIC HEALTH RELEVANCE: Intravenous administration of tPA is the only FDA-approved emergency treatment for ischemic stroke. Mainly because the risk of brain bleeding, only 2-5% stroke patients receive tPA in USA. Here we propose a new combination therapy of annexin A2 plus tPA, it will generate more beneficial thrombolytic enzyme plasmin with much lower tPA dose. By doing so, the combination will enhance clot lysis for blood flow restorage and reduce the risk of bleeding. These effects should prolong treatment window and improve long-term outcomes.

描述（由申请人提供）：静脉注射重组 tPA 仍然是唯一经 FDA 批准且经证实最有益的中风紧急治疗干预措施。然而，治疗时间窗短、出血转化、溶栓灌注率差和神经毒性是其应用的主要限制。在本提案中，我们假设重组膜联蛋白 A2 蛋白 (rA2) 将降低再灌注所需的 tPA 剂量，同时增强溶栓功效，并减轻脑内出血转化。通过这样做，它将延长治疗时间窗口并改善长期结果。我们的想法的分子基础是膜联蛋白 A2 通过与 tPA 和纤溶酶前体纤溶酶原组装纤溶复合物来加速溶解血栓的纤溶酶的产生。我们的试点数据很有希望。我们现在提出三个目标来研究这种新的联合疗法所涉及的机制。在目标 1 中，我们将研究大鼠局灶性栓塞性卒中后 4 小时使用 rA2 加低剂量 tPA 联合治疗的溶栓效果，通过 MR 血管造影确定再通和再闭塞，通过 MRI CBF 绘制脑血流图；脑血容量 (CBV)、微血管容量 (MVV) 和血管尺寸指数 (VSI) 的 MRI 测量，以量化血管对溶栓剂和血管扩张剂的反应。在目标 2 中，我们将研究 rA2 加低剂量 tPA 联合治疗对大鼠局灶性栓塞性卒中后 4 小时治疗的神经血管基质蛋白水解和 BBB 渗漏的影响。将测量脑梗塞、水肿和出血性转化的发展，并将其与 MMP-9 活性的时间曲线、细胞外基质成分的蛋白水解降解和 BBB 渗漏相关联。在目标 3 中，我们将评估中风后 4 小时时 rA2 加低剂量 tPA 组合治疗的长期结果。将对大鼠进行为期 4 周的跟踪，进行一系列行为测试。最后，取出大脑进行H&E病灶大小测量，检查脑血管密度和组织恢复因子VEGF、Ang-1表达。将低剂量 tPA 加 rA2 与单独的 rA2、单独的低剂量和高剂量 tPA 以及赋形剂盐水对照进行比较。如果成功，这些拟议的实验将为 rA2 加低剂量 tPA 如何改善 tPA 中风治疗提供新的见解，并可能最终产生一种新的组合方法来优化基于 tPA 的溶栓中风治疗。我们相信我们的提案应该与 PA-07-233“重症监护的多学科转化研究”(R01) 直接相关。公共卫生相关性：静脉注射 tPA 是 FDA 批准的唯一治疗缺血性中风的紧急治疗方法。主要是因为脑出血的风险，在美国只有2-5%的中风患者接受tPA。在这里，我们提出了一种新的膜联蛋白 A2 加 tPA 的联合疗法，它将以低得多的 tPA 剂量产生更有益的溶栓酶纤溶酶。通过这样做，该组合将增强血栓溶解以恢复血流并降低出血风险。这些作用应该会延长治疗窗口并改善长期结果。