MicroRNAs, Mitochondria and the Blood-Brain Barrier - Therapeutic Targets for Stroke

MicroRNA、线粒体和血脑屏障——中风的治疗靶点

• 批准号: 10587899
• 负责人: Xuefang Sophie Ren
• 金额: $ 45.34万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 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 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10587899
• 关键词: Acute; Affect; Autopsy; Bioenergetics; Blood - brain barrier anatomy; Brain; Brain Injuries; Cell Survival; Cognitive deficits; Complex; Data; Databases; Development; Disease; EF Hand Motifs; Elderly; Electron Transport; Endothelial Cells; Endothelium; Filament; Functional disorder; Genes; Glucose; Goals; Hemorrhage; Human; Impairment; In Vitro; Infarction; Integral Membrane Protein; Ischemia; Ischemic Stroke; Knock-out; Knockout Mice; Leucine Zippers; Magnetic Resonance Imaging; Maintenance; Measures; Mediating; Membrane Potentials; Messenger RNA; MicroRNAs; Middle Cerebral Artery Occlusion; Mitochondria; Mitochondrial Membrane Protein; Modeling; Molecular; Motor; Mouse Strains; Mus; Oxidative Phosphorylation; Oxygen; Persons; Plasma; Play; Production; Proteins; Recovery of Function; Research; Role; Sampling; Stroke; Structure; Testing; Therapeutic; Transfection; Translational Repression; Vascular Cell Adhesion Molecule-1; aged; aging brain; blood-brain barrier disruption; blood-brain barrier permeabilization; brain tissue; cell age; cerebrovascular; cognitive testing; comparison control; deprivation; effective therapy; experimental study; functional outcomes; human old age (65+); improved; improved outcome; in vitro Model; in vivo; in vivo Model; inhibitor; mitochondrial membrane; motor function improvement; nanoparticle; nanoparticle delivery; novel; novel therapeutics; overexpression; pre-clinical; sex; stroke model; stroke outcome; stroke patient; therapeutic target

Project Summary/Abstract Stroke is a debilitating disease, affecting >15 million people worldwide annually, the majority of which are over 65 years old. Developing effective treatments for older stroke patients remains a pressing need. Stroke causes disruption of the blood-brain barrier (BBB) to brain damage, hemorrhagic transformation (HT), and worse functional outcomes. We have discovered that mitochondrial energy production in cerebrovascular endothelial cells (CECs) plays a central role in maintenance of BBB integrity both in in vivo and in vitro models. We have found altered levels of several microRNAs (miRNAs) in plasma and primary CECs (pCECs) from aged stroke mice. Specifically, expression of miR-34a is upregulated in both the plasma and pCECs from aged stroke mice compared with sham controls. Notably, miR-34a is also upregulated in plasma from stroke patients compared to healthy controls. Overexpression of miR-34a in murine CECs (mCECs) increases BBB permeability, compromises mitochondrial oxidative phosphorylation (OxPhos), and reduces mitochondrial membrane potential (ΔΨm) while decreasing the levels of several mitochondrial related genes; Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) in human CECs (hCECs) and LETM domain containing 1 (LETMD1) in mCECs. Importantly, our preliminary data show that LETM1 is significantly reduced in CECs in autopsy samples from stroke patients compared with controls. Additionally, we have shown that global knockout of miR-34a (miR- 34a–/–) reduces infarct size and conversely, overexpression of miR-34a (miR-34aTG) increases infarct size in mice. Similarly, systemic delivery of antagomiR-34a (a miR-34a inhibitor) reduces infarct size and improves long-term functional recovery in stroke mice. Although our findings provide compelling evidence that miR-34a plays an important role in stroke pathophysiology, the mechanism by which endothelial miR-34a mediates brain damage is unknown, especially in aged models of stroke. The objective of this proposal is to investigate if endothelial specific miR-34a affects stroke outcomes in the aged brain. We hypothesize that endothelial miR-34a regulates BBB permeability, ischemic damage, hemorrhagic transformation, and stroke-induced deficits by inhibiting translation of LETM1 and LETMD1 leading to impaired mitochondrial bioenergetics in CECs. Aim 1 will test if endothelial specific knockout of miR-34a improves acute and long-term stroke outcomes in aged mice of both sexes. Aim 2 will identify a mechanism by which miR-34a inhibits translation of LETM1 and LETMD1 leading to impaired mitochondrial function in CECs following stroke. Aim 3 will determine the therapeutic potential of nanoparticle delivery of endothelial cell targeted miR-34a antagomir in aged stroke mice of both sexes. Our studies will elucidate the role of endothelial miR-34a in stroke. Understanding the preclinical effects of endothelial specific antagomiR-34a treatment is an important step in the development of novel therapies for elderly stroke patients.

项目摘要/摘要 中风是一种使人衰弱的疾病，每年在全球范围内影响> 1500万人，其中大多数已经结束 65岁。为老年人患者开发有效的治疗方法仍然是紧迫的需求。中风原因 血脑屏障（BBB）破坏脑损伤，出血转化（HT），更糟的 功能结果。我们发现脑血管内皮的线粒体能量产生 细胞（CEC）在体内和体外模型中维持BBB完整性方面都起着核心作用。我们有 发现从老年人中风的血浆和原代CEC（PCEC）中的几种microRNA（miRNA）的水平改变了 小鼠。特别是，在老年卒中小鼠的血浆和PCEC中，miR-34a的表达均已更新 与假对照相比。值得注意的是，中风患者的血浆中也更新了miR-34a 进行健康控制。 miR-34a在鼠CEC（MCEC）中的过表达增加了BBB的渗透性， 损害线粒体氧化物磷酸化（OXPHOS），并降低线粒体膜电位 （Δψm）同时降低了几个线粒体相关基因的水平；亮氨酸拉链 - 含有含有亮氨酸 人CEC（HCEC）中的跨膜蛋白1（LETM1）和含有1（LETMD1）的LETM域中 MCEC。重要的是，我们的初步数据表明，尸检样品中CEC的LETM1大大降低 与对照组相比，中风患者。此外，我们已经证明了miR-34a的全球敲除（mir- 34a - /–）降低了梗塞大小，相反，miR-34a（miR-34ATG）的过表达增加了小鼠的梗死大小。 同样，Antagomir-34a（miR-34a抑制剂）的全身递送减小了梗塞的大小并改善了长期 中风小鼠的功能恢复。尽管我们的发现提供了令人信服的证据，即miR-34a扮演 中风病理生理学的重要作用，内皮miR-34a介导脑损伤的机制 是未知的，尤其是在衰老的中风模型中。该提议的目的是调查内皮是否 特定的miR-34a会影响老年大脑的中风结果。我们假设内皮miR-34a调节 BBB渗透性，缺血性损害，出血转化和中风引起的缺陷 LETM1和LETMD1的翻译导致CEC中的线粒体生物能力受损。 AIM 1将测试是否 miR-34a的内皮特异性敲除可改善两者的急性和长期中风结果 性别。 AIM 2将确定miR-34a抑制LETM1和LETMD1翻译的机制 中风后CEC中的线粒体功能受损。 AIM 3将确定 两性男女老年人中风小鼠的内皮细胞的纳米颗粒递送。我们的 研究将阐明内皮miR-34a在中风中的作用。了解内皮的临床前效应 特定的Antagomir-34a治疗是开发新型中风疗法的重要步骤 患者。