LRP1 as a novel regulator of CXCR4 in adult neural stem cells and post-stroke response

LRP1 作为成体神经干细胞和中风后反应中 CXCR4 的新型调节剂

基本信息

批准号：
10701231
负责人：
Naomi Ledene Sayre
金额：
$ 36.74万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-15 至 2028-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10701231
关键词：
Ablation Acute Address Adult Affect Animals Automobile Driving Brain Brain Injuries C-terminal Cell Differentiation process Cell Nucleus Cell membrane Cells Clinical Cues Data Defect Disease Finding by Cause Future Genetic Transcription Glucose Home Impairment In Vitro Intervention Ischemia Ischemic Stroke Knock-out Knockout Mice LDL-Receptor Related Protein 1 Laboratories Learning Lesion Ligands Lipoprotein Receptor Malignant Neoplasms Measures Mediating Membrane Membrane Proteins Memory impairment Messenger RNA Methods Middle Cerebral Artery Occlusion Modeling Mus Neuroglia Neurologic Oxygen Pathway interactions Patients Process Production Proliferating Protein C Proteins Recovery Regulation Research Role Signal Transduction Signaling Protein Site Stem cell transplant Stroke Surgical Models Survivors Tertiary Protein Structure Testing Therapeutic Therapeutic Effect Time Tissues Transcriptional Regulation United States Up-Regulation brain repair burden of illness cell motility chemokine receptor chromatin immunoprecipitation deprivation disability experience extracellular functional disability healing improved in vivo insight ischemic lesion migration motor deficit motor impairment motor recovery mouse model nerve stem cell nestin protein neuroblast neuroprotection new therapeutic target news novel post stroke protein expression receptor receptor binding red fluorescent protein repaired response self-renewal stem cell biology stem cell function stem cell migration stem cell proliferation stem cell survival stroke outcome stroke recovery subventricular zone therapeutic target trafficking transcription factor virtual

项目摘要

Project Summary/Abstract The good news is that increasingly, patients who experience an ischemic stroke survive. Unfortunately, survivors are rarely unscathed — stroke is the leading cause of long-term disability in the U.S. Interventions are limited in part due to a lack of insight into secondary processes post-stroke. Neural stem cells (NSCs) have demonstrated therapeutic benefit in stroke recovery. But key questions remain that if answered, could enhance clinical use. NSCs normally migrate to the lesion, secrete pro-reparative factors, differentiate, and reduce secondary damage. Central to these benefits is the ability of NSCs to send and respond to specific environmental cues. Our data show NSC function is influenced by low-density lipoprotein receptor-related protein (LRP1), a multifunctional receptor that modulates cell signaling via multiple mechanisms. Despite an expansive role in signal modulation, the importance of LRP1 in NSC biology is virtually unstudied. We knocked-out LRP1 in adult NSCs and subjected mice to middle-cerebral artery occlusion. We found LRP1-KO in NSCs ablated migration to ischemic lesions. We also discovered that functional impairment and lesion size were reduced. This observation is somewhat paradoxical-physical localization of NSCs to lesions is often considered important to neuroprotective efficacy. We also found that LRP1-KO ablates expression of CXCR4, a chemokine receptor which is essential for migration to ischemic lesions. Thus, we seek to better understand how impaired LRP1 expression in NSCs is neuroprotective, and similarly to understand the mechanisms underlying LRP1 regulation of CXCR4. Our overall hypothesis is that LRP1 promotes NSC migration toward ischemic lesions through CXCR4 regulation, yet also limits the endogenous NSC-neuroprotective response. Our data suggest that LRP1 is a major driver of NSC response to signals. This proposal investigates LRP1, CXCR4, and NSC function in stroke using surgical models, in vivo, and in vitro approaches. We utilize a Nestin-CreERt2 mouse model to direct knock-out of LRP1 and/or CXCR4 in NSCs and to track these cells with expression of red fluorescent protein. Aim 1 tests the hypothesis that NSC-mediated neuroprotection is due to loss of LRP1, which promotes recovery independent of effects on CXCR4 by measuring post-stroke outcomes after rescuing expression of CXCR4 in mice with LRP1-KO in NSCs, or ablating LRP1 in mice with CXCR4-KO in NSCs. Aim 2 tests the hypothesis that loss of LRP1 (or CXCR4) is neuroprotective by enhancing post-stroke NSC neuroprotective response by interrogating the effect on NSC post-stroke response and survival, both in vivo and in vitro. Aim 3 tests the mechanism by which LRP1 regulates CXCR4 expression by rescuing LRP1 with domain-specific constructs and elucidating the effect on transcription, signaling, trafficking, and degradation of CXCR4. Data from these studies will define the value of NSC-LRP1 as a therapeutic target, identify discrete mechanisms of LRP1-mediated neuroprotection, and define the mechanism by which LRP1 regulates CXCR4 expression.

项目摘要/摘要好消息是，经历缺血性中风的患者越来越生存。不幸的是，幸存者很少毫发无损 - 中风是美国长期残疾的主要原因。部分是由于对中风后对次要过程缺乏见解。神经干细胞（NSC）已证明中风恢复中的治疗益处。但是，如果回答得出的话，仍然可以增强临床用途。 NSC通常会迁移到病变，秘密促贡献因素，区分和减少次要损害。这些好处的核心是NSC发送和响应特定环境线索的能力。我们的数据显示NSC功能受低密度脂蛋白受体相关蛋白（LRP1）的影响，一种多功能接收器通过多种机制调节细胞信号。尽管在信号调制中发挥了额外的作用，但 LRP1在NSC生物学中的重要性几乎没有研究。我们在成人NSC中敲出了LRP1，并受到了小鼠到中脑动脉阻塞。我们在NSC的消融迁移到缺血性病变中发现了LRP1-KO。我们还发现功能障碍和病变大小降低。这个观察有点 NSC在病变上的矛盾的物理定位通常被认为对神经保护效率很重要。我们还发现，LRP1-KO消融了CXCR4的表达，CXCR4是一种趋化因子接收器，对迁移到缺血性病变。那就是，我们试图更好地了解NSC中LRP1表达的受损是如何神经保护性，类似地了解CXCR4的LRP1调节机制。我们的整体假设是LRP1通过CXCR4调节促进NSC迁移到缺血性病变，但也限制了内源性NSC神经保护反应。我们的数据表明LRP1是主要驱动程序 NSC对信号的响应。该提案研究了使用手术的LRP1，CXCR4和NSC功能模型，体内和体外方法。我们利用Nestin-Creert2鼠标模型直接敲除LRP1 和/或CXCR4在NSC中，并以红色荧光蛋白的表达跟踪这些细胞。 AIM 1测试 NSC介导的神经保护是由于LRP1的丧失引起的，该假设促进了恢复通过测量在挽救CXCR4表达后的势后结果，独立于对CXCR4的影响 NSC中使用LRP1-KO的小鼠，或在NSC中用CXCR4-KO烧杯LRP1。 AIM 2检验假设 LRP1（或CXCR4）的损失是通过增强中风后NSC神经保护作用的神经保护性的通过在体内和体外询问对NSC势后反应和生存的影响的反应。目标3 测试LRP1通过用特定域特异性挽救LRP1来调节CXCR4表达的机制构建并阐明CXCR4的转录，信号传导，运输和降解的影响。数据从这些研究中将定义NSC-LRP1作为治疗靶标的价值，确定离散机制 LRP1介导的神经保护作用，并定义LRP1调节CXCR4表达的机制。