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视网膜退行性变(RD)相关的标志性病理之一。 在病人身上表现为渐进性失明的疾病。这包括异质性疾病。 例如全球每3500人中就有一人患有视网膜色素变性和老年性黄斑变性， 它影响着全球超过1.96亿人，预计到2040年将达到2.88亿人。 具体地说，在我们的退伍军人群体中，每年大约有7000名退伍军人因RD而视力受损。 临床试验和回顾研究表明，RD患者可能会对运动起到神经保护作用。 保护视力的治疗。最近，我们的实验室填补了一个重大的知识空白，证明了 适度运动保护RD模型的视网膜功能和结构，并伴随着增加 脑源性神经营养因子(BDNF)水平和所需的完整BDNF-TrkB信号转导。到目前为止， 调节运动的神经保护益处的细胞类型和分子过程尚不清楚。 其他研究表明，大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以及在这些细胞类型中改变的BDNF-TrkB信号有助于神经退行性变 疾病的进展和严重程度。最近，星形胶质细胞被证明可以改变其形态。 在神经退行性变过程中对大脑中的BDNF做出反应。同样，血管内皮细胞表达脑源性神经营养因子 在运动诱导的生理应激下。这些数据表明，星形胶质细胞和内皮细胞可能 调节运动对视网膜的神经保护作用。我们的方法是理解形态上的， 运动诱导视网膜星形胶质细胞和血管的基因表达和功能改变及其机制 这些变化有助于神经保护。在这个方案中，我们将使用BALB/c光诱导的视网膜 变性模型，在RD患者中发现的表型。我们假设那次演习 通过增加脑源性神经营养因子信号诱导视网膜星形胶质细胞可塑性和改善血管功能 机制，促进神经修复和保护。在具体目标1中，我们将调查运动是否 通过评估视网膜星形胶质细胞的形态、细胞基因表达来影响视网膜星形胶质细胞生物学 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，分析骨骼和 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分离 使用磁激活细胞分选(MACS)检测星形胶质细胞基因表达谱。监测视网膜 星形胶质细胞功能，一种新的星形胶质细胞介导的吞噬作用的体外活体成像将被使用。具体而言 目的研究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的量化分析。视网膜血管细胞基因 MACS将评估表达谱，血管功能将使用视网膜功能进行评估 充血。在特定的目标3中，我们将确定运动诱导的BDNF信号机制是否影响 视网膜星形胶质细胞和血管形态、基因表达和功能的研究 高度特异的TrkB受体拮抗剂ANA-12。视网膜星形胶质细胞和血管评估在 被发现信息量最大的具体目标1和2将被用来比较试验组。这个 这项研究的预期结果是运动诱导的BDNF信号改变了视网膜星形胶质细胞和血管 通过形态、基因表达和改善功能来促进视网膜神经保护。结果来自 这项研究将阐明形态、基因表达和功能变化最终导致 视网膜星形胶质细胞和血管系统的功能获得(S)和/或稳态功能丧失/上调(S)。 这一建议对优化运动疗法的长期目标具有深远的潜力 针对运动诱导保护的潜在机制创造新的药理学策略 在RD患者中，这可以扩展到其他神经退行性和神经炎性疾病。