Investigating the role of retinal astrocytes in exercise-induced retinal neuroprotection

研究视网膜星形胶质细胞在运动引起的视网膜神经保护中的作用

• 批准号: 10484539
• 负责人: Katie Leigh Bales
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10484539
• 关键词: Affect; Affinity; Age related macular degeneration; Animal Model; Astrocytes; Atrophic; Award; Biological Assay; Biology; Blindness; Blood Vessels; Brain; Brain-Derived Neurotrophic Factor; Cell Density; Cell Separation; Cells; Cellular Morphology; Clinical Research; Clinical Trials; Computer software; Data; Disease; Disease Progression; Endothelial Cells; Exercise; Exhibits; Foundations; Functional disorder; Future; Gene Expression; Goals; Healthcare; Hyperemia; Image; In Vitro; Inbred BALB C Mice; Inflammation; Intervention; Knowledge; Label; Light; Light Exercise; Magnetism; Mediating; Modeling; Modification; Molecular; Monitor; Morphology; Mus; Nerve Degeneration; Neurodegenerative Disorders; Neuronal Plasticity; Neurotrophic Tyrosine Kinase Receptor Type 2; Outcome Study; Pathogenesis; Pathology; Patients; Persons; Phagocytosis; Pharmacology; Phenotype; Photoreceptors; Physiological; Process; Research; Retina; Retinal Degeneration; Retinitis Pigmentosa; Retrospective Studies; Role; Severities; Severity of illness; Signal Transduction; Stress; Structure; Testing; Therapeutic; Translating; Up-Regulation; Vascular Endothelial Cell; Veterans; Vision; Visual impairment; Writing; antagonist; base; cell type; density; exercise intervention; experimental group; gain of function; gene function; improved; improved functioning; military veteran; mouse model; neural repair; neuroinflammation; neuroprotection; neurovascular coupling; novel; patient population; preservation; receptor; relating to nervous system; repaired; response

Photoreceptor dysfunction is one of the hallmark pathologies associated with retinal degenerative (RD) diseases that manifests in patients as a progressive loss of vision. This encompasses heterogenous diseases such as retinitis pigmentosa, which affects 1 in 3500 people worldwide and age-related macular degeneration, which affects over 196 million people worldwide and is projected to reach 288 million people by 2040. Specifically, in our Veteran population, roughly 7,000 Veterans become visually impaired each year due to RD. Clinical trials and retrospective studies suggest that RD patients may respond to exercise as a neuroprotective treatment to preserve vision. Recently, our labs filled a significant knowledge gap by demonstrating that modest exercise protects retinal function and structure in models of RD and were accompanied by increased levels of brain derived neurotrophic factor (BDNF) and required intact BDNF-TrkB signal transduction. To date, the cell-types and molecular processes mediating the neuroprotective benefits of exercise are unknown. Others have shown that astrocytes and endothelial cells in the brain express BDNF and its high-affinity receptor, TrkB, and that altered BDNF-TrkB signaling in these cell-types contributes to neurodegenerative disease progression and severity. Recently, it has been demonstrated that astrocytes modify their morphology in response to BDNF in the brain during neurodegeneration. Likewise, vascular endothelial cells express BDNF under exercise-induced physiological stress. These data suggest that astrocytes and endothelial cells may mediate the neuroprotective effects of exercise in the retina. Our approach is to understand the morphological, gene expression and functional alterations in retinal astrocytes and vasculature induced from exercise and how these alterations contribute to neuroprotection. For this proposal, we will use the BALB/c light induced retinal degeneration model, which exhibits phenotypes found in patients with RD. We hypothesize that exercise induces retinal astrocyte plasticity and improved vascular function through increased BDNF signaling mechanisms, promoting neural repair and protection. In Specific Aim 1, we will investigate if exercise influences retinal astrocyte biology, by assessing retinal astrocyte morphology, cellular gene expression profiles, and retinal astrocyte-mediated phagocytosis. Immunohistochemical labeling, AnalyzeSkeleton and Sholl analysis will be used to quantify astrocyte cell morphology and density. Retinal astrocytes will be isolated using magnetic-activated cell sorting (MACS) to examine astrocyte gene expression profiles. To monitor retinal astrocyte function, a novel in vitro live-imaging of astrocyte-mediated phagocytosis will be used. In Specific Aim 2, we will determine the effects of exercise on retinal vascular morphology, gene expression and function. Angiotool will be used for retinal vascular morphology quantification analysis. Retinal vascular cell gene expression profiles will be assessed by MACS and vascular function will be assessed using retinal functional hyperemia. In Specific Aim 3, we will determine if exercise-induced BDNF signaling mechanisms influence retinal astrocyte and vascular morphology, gene expression and function, by blocking BDNF signaling using a highly specific TrkB receptor antagonist, ANA-12. Retinal astrocyte and vascular assessments performed in Specific Aims 1 and 2 found to be most informative will be used to compare experimental groups. The expected outcome of this study is that exercise-induced BDNF signaling alters retinal astrocyte and vascular morphology, gene expression and improves function in order to promote retinal neuroprotection. Results from this study will illuminate the morphological, gene expression and functional alterations that ultimately result in gain of function(s) and or loss/upregulation of homeostatic function(s) in retinal astrocytes and vasculature. This proposal holds profound potential for the long-term goals of optimizing exercise-based therapeutics and creating new pharmacological strategies targeting the underlying mechanisms of exercise-induced protection in patients with RD that can be extended to other neurodegenerative and neuroinflammatory diseases.

光感受器功能障碍是与视网膜退行性（RD）相关的标志性病变之一 在患者中表现为逐渐失去视力的疾病。这包括异质疾病 例如色素性视网膜炎，影响全球3500人中的1人和与年龄相关的黄斑变性， 它影响了全球超过1.96亿人，预计到2040年将达到2.88亿人口。 具体来说，在我们的资深人口中，由于RD，每年大约有7,000名退伍军人受到视觉障碍。 临床试验和回顾性研究表明，RD患者可以作为神经保护作用反应运动 治疗以保持视力。最近，我们的实验室通过证明 适度的运动可保护RD模型中的视网膜功能和结构，并伴随着增加 脑衍生的神经营养因子（BDNF）的水平，并需要完整的BDNF-TRKB信号转导。迄今为止， 介导运动神经保护益处的细胞类型和分子过程尚不清楚。 其他人则表明，脑中的星形胶质细胞和内皮细胞表达BDNF及其高亲和力 受体，TRKB以及这些细胞类型中的BDNF-TRKB信号传导有助于神经退行性 疾病的进展和严重程度。最近，已经证明星形胶质细胞改变其形态 在神经退行性过程中响应大脑中的BDNF。同样，血管内皮细胞表达BDNF 在运动引起的生理压力下。这些数据表明，星形胶质细胞和内皮细胞可能 介导视网膜中运动的神经保护作用。我们的方法是了解形态学， 运动引起的视网膜星形胶质细胞和脉管系统的基因表达和功能改变以及如何 这些改变有助于神经保护。对于此提案，我们将使用BALB/C诱导的视网膜 变性模型，该模型在RD患者中显示出表型。我们假设该练习 通过增加的BDNF信号传导诱导视网膜星形胶质细胞可塑性和改善的血管功能 机制，促进神经修复和保护。在特定目标1中，我们将调查是否运动 通过评估视网膜星形胶质细胞形态，细胞基因表达来影响视网膜星形胶质细胞生物学 特征和视网膜星形胶质细胞介导的吞噬作用。免疫组织化学标记，分析和分析 Sholl分析将用于量化星形胶质细胞的形态和密度。视网膜星形胶质细胞将被隔离 使用磁性细胞分选（MAC）检查星形胶质细胞基因表达谱。监测视网膜 星形胶质细胞功能是一种新型的体外体外现场现象，用于星形胶质细胞介导的吞噬作用。具体 AIM 2，我们将确定运动对视网膜血管形态，基因表达和功能的影响。 Angiotool将用于视网膜血管形态定量分析。视网膜血管细胞基因 表达曲线将通过MAC评估，并且将使用视网膜功能评估血管功能 充血。在特定目标3中，我们将确定运动诱导的BDNF信号传导机制是否影响 视网膜星形胶质细胞和血管形态，基因表达和功能，通过使用A阻断BDNF信号 高度特异性的TRKB受体拮抗剂ANA-12。视网膜星形胶质细胞和血管评估 发现最有用的特定目的1和2将用于比较实验组。这 这项研究的预期结果是运动诱导的BDNF信号传导改变了视网膜星形胶质细胞和血管 形态，基因表达和改善功能以促进视网膜神经保护。结果 这项研究将阐明形态学，基因表达和功能改变，最终导致 视网膜星形胶质细胞和脉管系统中稳态功能（S）功能的增益和或损失/上调。 该提议具有优化基于运动的治疗剂和的长期目标的巨大潜力 创建针对运动引起保护的潜在机制的新药理策略 RD患者可以扩展到其他神经退行性和神经炎症性疾病。