Role of Astrocytic miR-20a-3p as a Potential Therapeutic for Ischemic Stroke

星形细胞 miR-20a-3p 作为缺血性中风的潜在治疗药物的作用

• 批准号: 10611836
• 负责人: Taylor Branyan
• 金额: $ 3.53万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10611836
• 关键词: Adenoviruses; Affect; Age; Aging; Animal Model; Apoptotic; Astrocytes; Attenuated; Behavioral Assay; Bioinformatics; Biological Assay; Cell Hypoxia; Cell Survival; Cells; Chromatin; Corpus striatum structure; Culture Media; Data; Development; Disease; Down-Regulation; Drug Delivery Systems; Enzyme-Linked Immunosorbent Assay; Epigenetic Process; Estrogen Replacements; Estrogens; Exhibits; Female; Gene Proteins; Gene Transfer; Gene Transfer Techniques; Genes; Genetic Transcription; Genome; Glial Fibrillary Acidic Protein; Glutamates; Goals; Hour; Human; Hypoxia; Impairment; In Vitro; Infarction; Inflammation Mediators; Inflammatory; Injections; Ischemic Stroke; Link; Mediating; Menopause; MicroRNAs; Middle Cerebral Artery Occlusion; Mitochondria; Modeling; Modernization; Modification; Neuroprotective Agents; Oligonucleotides; Organelles; Outcome; Ovarian hormone; Perimenopause; Peripheral; Population; Premenopause; Production; Proteins; Quantitative Reverse Transcriptase PCR; RNA; Rattus; Recombinant adeno-associated virus (rAAV); Recovery; Research; Risk; Role; Scientist; Sensorimotor functions; Severities; Stroke; Supplementation; System; Testing; Therapeutic; Time; Woman; Women' s Group; age related; brain cell; career; clinically relevant; cytokine; experience; extracellular vesicles; histone methylation; improved; in silico; in vivo; insight; member; men; middle age; neuroprotection; neurotoxic; novel therapeutics; post stroke; pre-clinical research; promoter; reproductive; senescence; sex; stroke incidence; stroke model; stroke outcome; stroke risk; therapeutic development; therapeutic target; translational potential

Project Summary The goal of this project is to test a therapeutic compound that has the potential to improve stroke outcomes in older females. It is critical to focus on this demographic because studies show that after menopause, women have greater risk and severity of ischemic stroke. Previous studies from the sponsor's lab have shown that reproductively senescent (acyclic) (RS) female rats have larger infarct and worse sensorimotor impairments than younger females. Moreover, estrogen replacement to RS females exacerbates stroke impairment. Thus this animal model replicates key features of stroke-related consequences seen in the human population, resulting in a model with translational potential, in which neurotherapeutic compounds can be tested. Prior research from the sponsor's lab has shown that astrocytes from reproductively senescent (RS) female rats exhibit age-related changes that contribute to poorer recovery after stroke. This includes a reduced capacity for glutamate clearance, decreased secretion of trophic factors, and increased release of inflammatory cytokines, compared to younger females. Furthermore, these aging astrocytes also display reduced histone methylation of the H3K4 chromatin region, resulting in less transcription of several genes including the microRNA mir-17-92 cluster. MicroRNAs have recently gained popularity as potential therapeutics for a variety of conditions, including ischemic stroke. Preliminary data for this proposal shows that miR-20a-3p, a member of the mir-17-92 cluster is dramatically down regulated in astrocytes of middle-aged females. Furthermore, iv injection of miR-20a-3p mimics four hours after middle cerebral artery occlusion (MCAo) decreased infarct volume and attenuated sensorimotor impairment in middle-aged females, suggesting that the miR-20a-3p could be mechanistically linked to stroke outcomes. This raises the intriguing possibility that in younger females, endogenous astrocyte-derived miR- 20a-3p may be `distributed' to other cells to improve stroke outcomes. This hypothesis will be tested in the following aims: Aim 1 will determine whether miR-20a-3p alters the composition of astrocytice extracellular vesicles (EVs) and that miR-20a-3p modified EVs will confer neuroprotection. Astrocytes have been shown to release neuroprotective factors, organelles and RNA translational machinery through EVs after stroke. In silico analysis predicts that miR-20a-3p may regulate inflammatory mediators and mitochondrial genes. Thus, miR- 20a-3p could drastically change the composition of the EVs. In aim 2, replication-deficient adenovirus constructs will be used to increase miR-20a-3p levels only in astrocytes and determine whether this recapitulates the neuroprotective effect of iv miR-20a-3p. Using clinically relevant stroke models, a battery of behavioral assays, and modern gene transfer techniques, this proposal will critically examine whether modification of the aging astrocyte will promote neuroprotection.

项目概要 该项目的目标是测试一种治疗化合物，该化合物有可能改善中风结果 年长的女性。关注这一人群至关重要，因为研究表明，绝经后，女性 缺血性中风的风险和严重程度更高。申办者实验室之前的研究表明 生殖衰老（无环）（RS）雌性大鼠梗死面积更大，感觉运动障碍更严重 比年轻女性。此外，对RS雌性进行雌激素替代会加剧中风损伤。因此 该动物模型复制了人类中风相关后果的关键特征， 产生具有转化潜力的模型，可以在其中测试神经治疗化合物。 赞助商实验室之前的研究表明，来自生殖性衰老（RS）雌性大鼠的星形胶质细胞 表现出与年龄相关的变化，导致中风后恢复较差。这包括减少容量 谷氨酸清除率，营养因子分泌减少，炎症细胞因子释放增加， 与年轻女性相比。此外，这些衰老的星形胶质细胞还表现出组蛋白甲基化减少 H3K4 染色质区域，导致包括 microRNA mir-17-92 在内的多个基因转录减少 簇。 MicroRNA 最近作为多种疾病的潜在疗法而受到欢迎， 包括缺血性中风。 该提案的初步数据表明，mir-17-92 簇的成员 miR-20a-3p 显着 中年女性星形胶质细胞下调。此外，静脉注射 miR-20a-3p 模拟了四种 大脑中动脉闭塞（MCAo）后数小时，梗塞体积减少，感觉运动减弱 中年女性的损伤，表明 miR-20a-3p 可能与中风存在机制相关 结果。这提出了一个有趣的可能性，即在年轻女性中，内源性星形胶质细胞衍生的 miR- 20a-3p可以“分布”到其他细胞以改善中风结果。该假设将在 目标如下：目标 1 将确定 miR-20a-3p 是否改变星形胶质细胞胞外的组成 囊泡 (EV) 和 miR-20a-3p 修饰的 EV 将赋予神经保护作用。星形胶质细胞已被证明 中风后通过 EV 释放神经保护因子、细胞器和 RNA 翻译机制。计算机模拟 分析预测miR-20a-3p可能调节炎症介质和线粒体基因。因此，miR- 20a-3p 可能会极大地改变电动汽车的构成。目标 2，复制缺陷型腺病毒 构建体将用于仅在星形胶质细胞中增加 miR-20a-3p 水平，并确定这是否 概括了 iv miR-20a-3p 的神经保护作用。使用临床相关的中风模型，一组 行为分析和现代基因转移技术，该提案将严格审查是否 老化星形胶质细胞的修饰将促进神经保护。