Vascular Injury and Recovery in Diabetic Ischemic Stroke

糖尿病缺血性中风的血管损伤和恢复

• 批准号: 8848660
• 负责人: ADVIYE ERGUL
• 金额: $ 2.59万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8848660
• 关键词: Acute; Address; Affect; Alteplase; Animal Model; Animals; Attenuated; Blood Vessels; Brain; Cerebrovascular Circulation; Cerebrum; Clinical; Data; Deposition; Development; Diabetes Mellitus; Endothelial Cells; Generations; Goals; Health; Hemorrhage; Human; Hypoxia; In Vitro; Infarction; Inflammation; Injury; Iron; Iron Chelation; Ischemic Stroke; Knowledge; Mechanics; Mediating; Modeling; Molecular; Neurologic; Neuronal Plasticity; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Outcome; Pathologic Neovascularization; Pathology; Patients; Pattern; Population; Prevention; Process; Recovery; Recovery of Function; Reperfusion Injury; Reperfusion Therapy; Research; Risk; Role; Severities; Signal Transduction; Stroke; TLR4 gene; Testing; Vascular Diseases; base; brain repair; density; diabetic; diabetic patient; diabetic rat; experience; functional outcomes; high risk; improved; in vivo Model; iron chelation therapy; novel; novel therapeutics; public health relevance; repaired; restoration; stroke recovery; therapeutic target; toll-like receptor 4; translational study

DESCRIPTION (provided by applicant): More than 7% of the US population who have diabetes are at a 2 to 6-fold higher risk for having ischemic stroke and suffer from unfavorable stroke outcome and poor recovery. Reperfusion therapy with tissue plasminogen activator (tPA) is the only therapy for ischemic stroke; however, this treatment increases the risk of bleeding into the brain (hemorrhagic transformation, HT), especially in diabetics. A critical barrier to progress in the development of new therapeutic strategies, as well as the proper use of tPA in high-risk populations, is the lack of understanding on how bleeding influences the repair and recovery after stroke. Our goal is to identify new targets for prevention and treatment of stroke i patients with preexisting vascular disease and develop new neurovascular protection strategies. Our objective is to address this critical barrier and clinical problem by defining the impact and mechanisms by which HT impairs neurovascular repair after ischemic stroke in diabetes. Our central hypothesis is that bleeding into the brain, petechial OR space- occupying, impairs neurovascular restoration and worsens outcome in diabetes via the activation of toll like receptor (TLR)-4 by excess iron, a novel damage associated molecular pattern (DAMP). This hypothesis will be tested in 3 Specific Aims: 1. Test the hypothesis that petechial nonspace-occupying HT impairs neurovascular restorative repair and worsens neurological deficits in diabetes. We will determine the extent to which HT impairs neurovascular repair and functional outcome in multiple models of stroke and diabetes; 2. Test the hypothesis that iron deposition resulting from greater HT in diabetes impairs neurovascular plasticity and worsens outcome of ischemic stroke. We will determine the role of iron on neurovascular restoration and functional outcome after embolic stroke in Type 2 diabetes; and 3. Test the hypothesis that HT stimulates TLR4 signaling/inflammation worsening repair and recovery after diabetic ischemic stroke. We will determine the mechanisms by which HT impairs functional recovery after embolic stroke in Type 2 diabetes. The outcomes of our translational studies include: 1) demonstrating that any bleeding into the brain is detrimental by impairing vascular and neuronal repair (this challenges the existing paradigm that only space-occupying HT worsens outcomes); 2) generating new and important data related to mechanisms of how diabetes attenuates neuronal and endothelial repair processes by using combinations of animal models of diabetes or stroke to recapitulate the clinical condition, and 3) identification of iron as a new DAMP and show that iron chelation and/or downstream TLR4 inhibition are promising therapeutic targets in stroke treatment/recovery. This project will have a significant positive impact on stroke research and human health because it will 1) identify neurovascular protection and restoration strategies to improve stroke outcomes, 2) advance our knowledge of the role of the cerebral vasculature in stroke repair, and 3) provide specific information on stroke recovery in diabetes which occurs in more than 30% of the 800,000 annual stroke victims.

描述（由申请人提供）：超过 7% 的美国糖尿病患者患缺血性中风的风险高出 2 至 6 倍，并且中风结果不佳且恢复不佳。使用组织纤溶酶原激活剂（tPA）进行再灌注治疗是治疗缺血性中风的唯一方法；然而，这种治疗会增加大脑出血（出血性转化，HT）的风险，尤其是糖尿病患者。阻碍新治疗策略开发以及在高危人群中正确使用 tPA 的一个关键障碍是缺乏对出血如何影响中风后修复和恢复的了解。我们的目标是确定预防和治疗患有血管疾病的中风患者的新目标，并开发新的神经血管保护策略。我们的目标是通过明确 HT 损害糖尿病缺血性中风后神经血管修复的影响和机制来解决这一关键障碍和临床问题。我们的中心假设是，过量铁（一种新的损伤相关分子模式（DAMP））激活 Toll 样受体（TLR）-4，导致大脑出血（瘀点或占位）损害神经血管恢复并恶化糖尿病的预后。该假设将在 3 个具体目标中得到检验： 1. 检验以下假设：瘀点非占位性 HT 会损害神经血管的恢复性修复并加重糖尿病患者的神经功能缺损。我们将确定 HT 在多种中风和糖尿病模型中损害神经血管修复和功能结果的程度； 2. 检验以下假设：糖尿病中较高的 HT 导致铁沉积会损害神经血管可塑性并使缺血性中风的结果恶化。我们将确定铁对 2 型糖尿病栓塞性中风后神经血管恢复和功能结果的作用； 3. 检验 HT 刺激 TLR4 信号/炎症从而恶化糖尿病缺血性中风后修复和恢复的假设。我们将确定 HT 损害 2 型糖尿病栓塞性中风后功能恢复的机制。我们的转化研究的结果包括：1）证明任何进入大脑的出血都会损害血管和神经元的修复（这挑战了现有的范式，即只有占位性 HT 才会恶化结果）； 2) 通过使用糖尿病或中风动物模型的组合来概括临床状况，生成与糖尿病如何减弱神经元和内皮修复过程的机制相关的新的重要数据，以及 3) 将铁鉴定为新的 DAMP 并表明铁螯合和/或下游 TLR4 抑制是中风治疗/恢复中有希望的治疗靶点。该项目将对中风研究和人类健康产生重大积极影响，因为它将 1) 确定神经血管保护和恢复策略以改善中风结果，2) 增进我们对脑血管系统在中风修复中作用的认识，3) 提供有关糖尿病患者中风康复的具体信息，每年 800,000 名中风患者中，有 30% 以上患有糖尿病。