Defining the Spatiotemporal Underpinnings of Neutrophil Recruitment, Microvascular Flow, and Oxygenation in Ischemic Stroke

定义缺血性中风中中性粒细胞募集、微血管血流和氧合的时空基础

• 批准号: 10449713
• 负责人: Neil Avadhoot Nadkarni
• 金额: $ 27.61万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10449713
• 关键词: Acceleration; Address; Adhesions; Angiography; Antibodies; Area; Atherosclerosis; Autopsy; Beds; Biology; Blocking Antibodies; Blood Pressure; Blood Vessels; Blood flow; Brain; Brain Hypoxia; Brain Infarction; Brain region; CD31 Antigens; Cancer Biology; Cell Adhesion Molecules; Cerebrovascular system; Cessation of life; Clinical; Clinical Research; Clinical Trials; Confocal Microscopy; Data; Disease; Endothelium; Environmental sludge; Extravasation; Feedback; Goals; Heterogeneity; Histopathology; Hour; Human; Imaging Techniques; Impairment; In Situ; Infarction; Infiltration; Inflammation; Inflammatory Infiltrate; Invaded; Investigation; Ischemia; Ischemic Penumbra; Ischemic Stroke; Knowledge; Lesion; Leukocytes; Link; Location; Magnetic Resonance Imaging; Measures; Mechanics; Mentorship; Microcirculation; Microscopy; Middle Cerebral Artery Occlusion; Molecular; Mus; Neurological outcome; Neutrophil Infiltration; Obstruction; Optical Coherence Tomography; Outcome; Oxygen; Pathologic; Pathology; Patients; Pattern; Perfusion; Physiological; Physiology; Population; Positioning Attribute; Property; Reperfusion Injury; Reperfusion Therapy; Research; Resolution; Risk; Stroke; Surface; Techniques; Testing; Therapeutic; Therapeutic Index; Thrombectomy; Time; Tissues; Toxic effect; Transgenic Mice; Visible Radiation; animal imaging; cerebral microvasculature; cerebrovascular; cytotoxicity; disability; improved; in vivo; insight; meter; migration; mouse model; multidisciplinary; multimodality; neuroinflammation; neutrophil; novel; novel therapeutics; post stroke; postcapillary venule; pre-clinical; preclinical study; programs; recruit; response; spatiotemporal; stroke model; stroke outcome; stroke patient; stroke therapy; success

Project Summary: While mechanical thrombectomy has advanced the treatment of large vessel occlusion (LVO) stroke, over 50% of patients still suffer from significant disability or death. Ischemia/reperfusion injury (I/RI), the result of restoring blood flow to deeply ischemic tissue, accelerates recruitment of polymorphonuclear neutrophils (PMNs). PMNs exert poor outcomes in two ways. First, PMNs physically obstruct cerebral microvessels in the stroke bed despite macrovascular reperfusion – a condition known as microvascular ‘no-reflow’. Second, PMNs exert toxic effects regionally once recruited at postcapillary venules and extravasated into the infarcted brain. Accordingly, preclinical studies that block PMN recruitment have had success in reducing stroke burden and improving neurologic outcome. Unfortunately, these preclinical studies have not been successful in human trials. These translational roadblocks may be addressed by investigating the spatiotemporal determinants of PMN recruitment as it relates to the in vivo cerebrovasculature during stroke. Using a mouse stroke model to simulate the LVO population and novel histopathological and imaging techniques, my preliminary data have found that PMN recruitment throughout I/RI is non-uniform up to 72 hours after infarction. PMNs were also found to progress cortically to subcortically throughout I/RI over the course of 72 hours, with partial restriction to the cortical surface by administration of an antibody that blocks transendothelial migration (TEM). These results support the concept of stroke microenvironments – highly regionalized areas within an infarct where inflammation and impaired microcirculation interface with each other. I hypothesize that these stroke microenvironments within an infarct are due to feedback loops between 1) microvascular flow and oxygenation; and 2) PMN recruitment. To test this hypothesis, I will investigate two aims: 1) Defining and physiologically manipulating the stroke microenvironment 2) Determine how PMN infiltration and position regulates I/RI over time. I will test these aims using techniques of multimodal in vivo animal imaging, advanced microscopy, and targeted manipulation of both leukocyte biology and stroke physiology. These studies will ultimately be used to identify molecular similarities of PMNs in particularly toxic stroke microenvironments, facilitating the investigation and creation of novel leukocyte-based therapies. To complete these long-term goals, I will incorporate a multidisciplinary mentorship team and short-term goals of developing expertise in live-animal imaging, advanced microscopy, and leukocyte biology. With this K08 proposal, I will build a unique translational stroke program that defines the interplay of stroke physiology and pathology to develop more precise and translatable therapies for stroke patients.

项目摘要：虽然机械取栓术促进了大血管闭塞的治疗 在左心室(LVO)卒中患者中，仍有超过50%的患者存在严重残疾或死亡。缺血/再灌注损伤 (I/RI)是深度缺血组织恢复血流的结果，加速了中性粒细胞的募集 中性粒细胞(PMN)。PMN在两个方面造成了糟糕的结果。首先，PMN在物理上造成了障碍 尽管大血管再灌注，卒中床上的脑微血管--一种称为微血管的情况 “无回流”。第二，中性粒细胞一旦聚集在毛细血管后小静脉并渗出，就会在局部产生毒性作用。 进入脑梗塞的大脑。因此，阻止PMN招募的临床前研究已经成功地减少了 中风负担和改善神经预后。不幸的是，这些临床前研究并没有 在人体试验中取得了成功。这些翻译障碍可以通过研究时空关系来解决 卒中期间PMN募集与体内脑血管系统相关的决定因素。使用鼠标 模拟LVO人群的卒中模型和新的组织病理学和成像技术，我的初步研究 数据发现，在脑梗塞后72小时，PMN在整个I/RI期间的募集是不均匀的。PMN是 在72小时的过程中，还发现在I/RI期间从皮质进展到皮质下，但有部分限制 通过注射一种抗体来阻止跨内皮细胞迁移(TEM)，将其转移到皮质表面。这些 结果支持卒中微环境的概念--梗死区内高度区域化的区域 炎症和微循环受损相互作用。我推测这些中风 脑梗塞内的微环境是由于1)微血管流动和氧合之间的反馈循环所致； 2)PMN招募。为了验证这一假设，我将调查两个目的：1)定义和生理上的 操纵卒中微环境2)确定PMN渗透和位置如何调节I/RI 时间到了。我将使用多模式活体动物成像、高级显微镜和 白细胞生物学和中风生理学的靶向操作。这些研究最终将被用来 确定在特别有毒的卒中微环境中PMN的分子相似性，为研究提供便利 以及创造新的基于白细胞的疗法。为了完成这些长期目标，我将纳入一个 多学科指导团队和发展活体动物成像专业知识的短期目标，高级 显微镜和白细胞生物学。有了这个K08提案，我将构建一个独特的翻译笔划程序 明确中风生理学和病理学的相互作用，以开发更精确和可翻译的治疗方法 中风患者。