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：机械取栓技术推进了大血管闭塞的治疗 (LVO) 中风，超过 50% 的患者仍然遭受严重残疾或死亡。缺血/再灌注损伤 (I/RI) 是恢复深度缺血组织血流的结果，加速多形核的募集 中性粒细胞（PMN）。 PMN 通过两种方式产生不良结果。首先，PMN 会物理阻碍 尽管存在大血管再灌注，但中风床上的脑微血管仍然存在——这种情况称为微血管 “无回流焊”。其次，PMN 一旦在毛细血管后微静脉中募集并外渗，就会产生局部毒性作用 进入梗塞的大脑。因此，阻止 PMN 募集的临床前研究已成功减少 中风负担和改善神经系统结果。不幸的是，这些临床前研究尚未得到证实。 在人体试验中取得成功。这些翻译障碍可以通过研究时空来解决 PMN 募集的决定因素，因为它与中风期间的体内脑血管系统有关。使用鼠标 模拟 LVO 群体的中风模型以及新颖的组织病理学和成像技术，我的初步研究 数据发现，梗死后 72 小时内，整个 I/RI 中的 PMN 募集并不均匀。 PMN 是 还发现在 72 小时的整个 I/RI 过程中，皮质向皮质下进展，但有部分限制 通过施用阻断跨内皮迁移（TEM）的抗体到达皮质表面。这些 结果支持中风微环境的概念——梗塞内高度区域化的区域，其中 炎症和微循环受损是相互影响的。我假设这些中风 梗塞内的微环境是由于以下因素之间的反馈回路造成的：1) 微血管流动和氧合； 2) PMN 招募。为了检验这个假设，我将研究两个目标：1）定义和生理学 操纵中风微环境 2) 确定 PMN 浸润和位置如何调节 I/RI 时间。我将使用多模式体内动物成像、先进显微镜技术和技术来测试这些目标 白细胞生物学和中风生理学的有针对性的操纵。这些研究最终将用于 识别中性粒细胞在特别有毒的中风微环境中的分子相似性，促进研究 并创建新的基于白细胞的疗法。为了完成这些长期目标，我将纳入 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 显微镜学和白细胞生物学。通过这个 K08 提案，我将构建一个独特的平移中风程序， 定义中风生理学和病理学的相互作用，以开发更精确和可转化的治疗方法 中风患者。