Role of choroidal macrophages in regulating lipid homeostasis and immunosuppression of the RPE/choroid

脉络膜巨噬细胞在调节 RPE/脉络膜脂质稳态和免疫抑制中的作用

• 批准号: 10313006
• 负责人: Seth D Fortmann
• 金额: $ 3.93万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10313006
• 关键词: Adipose tissue; Age; Age related macular degeneration; Age-Years; Alzheimer' s Disease; American; Anatomy; Anti-Inflammatory Agents; Area; Atherosclerosis; Basement membrane; Bioinformatics; Blindness; Blood Vessels; Cells; Cessation of life; Choroid; Choroidal Neovascularization; Chronic; Clinic; Clinical; Competence; Data; Deposition; Disease; Down-Regulation; Drusen; Ecosystem; Elderly; Enzyme-Linked Immunosorbent Assay; Evaluation; Excision; Exudative age-related macular degeneration; Eye; FDA approved; Fatty Liver; Flow Cytometry; Foundations; Functional disorder; Genes; Genetic Polymorphism; Goals; Grant; Health; High Fat Diet; Histologic; Homeostasis; Human; Immune; Immunohistochemistry; Immunosuppression; Individual; Inflammation; Inflammation Mediators; Inflammatory; Interleukin-1 beta; Knockout Mice; Lasers; Lipid Binding; Lipids; Lipoproteins; Location; Maintenance; Malignant Neoplasms; Mediating; Membrane; Mentors; Microglia; Modeling; Molecular; Morphology; Mus; Myeloid Cells; Neurodegenerative Disorders; Nonexudative age-related macular degeneration; Obesity; Ophthalmologist; Oral; Pathogenesis; Pathway interactions; Patients; Pericytes; Peripheral; Phagocytes; Phagocytosis; Pharmaceutical Preparations; Phase I Clinical Trials; Photoreceptors; Physicians; Play; Population; Primary Cell Cultures; Relative Risks; Research; Research Proposals; Retinal Diseases; Risk Factors; Role; Safety; Sampling; Scientist; Senile Plaques; Signal Transduction; Stains; Structure of retinal pigment epithelium; TNF gene; TREM2 gene; Techniques; Testing; Therapeutic; Time; Tissue Donors; Tissues; Training; Tumor-associated macrophages; Vision; career; density; design; disorder of macula of retina; ex vivo imaging; experience; extracellular; fovea centralis; genetic risk factor; human imaging; imaging study; immunoregulation; in vivo imaging; lipid metabolism; macrophage; macula; neovascular; neovascularization; new therapeutic target; novel; p65; receptor binding; relating to nervous system; response; responsible research conduct; serial imaging; single-cell RNA sequencing; tissue repair; transcriptome; transcriptome sequencing; transcriptomics; translational study; uptake

PROJECT SUMMARY Few therapeutic options exist for patients with age-related macular degeneration (AMD), and no FDA approved drugs are available for the most common subtype, dry AMD. Longitudinal imaging studies have identified the accumulation of drusen near the fovea as the single greatest anatomic risk factor for progression to severe disease, suggesting that loss of lipid homeostasis in the retinal pigmented epithelium (RPE) and choroid is a critical disease mechanism underlying AMD. Moreover, histologic and molecular studies have shown that inflammation of the macular RPE/choroid is an early, unifying feature of AMD. Yet, the molecular and cellular mechanisms responsible for the accumulation of lipid and inflammation in the RPE/choroid remain poorly understood. Using publicly available bulk and single-cell RNA-sequencing data from 150 human donors, we demonstrate that choroidal macrophages—a critical component of the choroidal ecosystem required for maintenance of the choriocapillaris and RPE function—are decreased and dysfunctional in the macular RPE/choroid in AMD. We detail novel transcriptomic observations related to the molecular underpinnings of choroidal macrophages in humans, demonstrating that they are robustly anti-inflammatory and express several key modules involved in lipid clearance. Of note is the expression of triggering receptor expressed on myeloid cells 2 (TREM2), a liporeceptor that mediates lipid homeostasis and immunosuppression in a range of tissues and is lost in several diseases involving accumulation of extracellular material. Using choroidal tissue from mice, we employ a variety of techniques to validate key findings related to choroidal macrophages. We show that choroidal macrophages are important in maintaining lipid homeostasis in the choroid during times of chronic lipid challenge, as these cells expand and contain nearly all of the excess lipid after 9 weeks of high-fat diet. These findings led us to our core hypothesis that TREM2+ choroidal macrophages modulate lipid homeostasis in the RPE/choroid and suppress inflammation and choroidal neovascularization. We propose two Aims using TREM2 knock-out mice to interrogate the role of TREM2 signaling in choroidal macrophages with respect to lipid metabolism and immune and neovascular suppression in the RPE/choroid. We anticipate the findings from this proposal will expand our understanding of the role of choroidal macrophages in the choroidal ecosystem and will identify TREM2 as a novel drug target in AMD. The proposed training plan for the PI, Seth Fortmann, is sponsored by his mentor, Dr. Maria Grant MD. The overall goal of the training plan is to provide the PI with a strong scientific foundation for a successful career as a physician-scientist ophthalmologist. Included in the training plan are experiences that will help the PI: 1) gain competence in a variety of techniques including bioinformatics, flow cytometry, primary cell culture, and ex vivo imaging of human donor eyes; 2) develop hypothesis-driven research; 3) present data in an oral and written format; 4) effectively integrate research with the clinic; 5) collaborate with other scientists; and 6) responsibly conduct research.

项目摘要 与年龄相关的黄斑变性（AMD）患者的治疗选择很少，没有FDA 批准的药物可用于最常见的亚型干燥AMD。纵向成像研究具有 确定中央凹附近的drusen的积累是进展的最大解剖风险因素 严重疾病，表明视网膜猪上皮（RPE）和 脉络膜是AMD基础的关键疾病机制。此外，组织学和分子研究表明 黄斑RPE/脉络膜的炎症是AMD的早期，统一的特征。然而，分子和细胞 负责脂质和炎症在RPE/脉络膜中积累的机制保持较差 理解齿。使用来自150名人类捐助者的公开批量和单细胞RNA的数据，我们 证明脉络膜巨噬细胞是脉络膜生态系统的关键组成部分 维持绒毛膜毛细血管和RPE功能 - 在黄斑中改善和功能失调 AMD中的RPE/脉络膜。我们详细介绍了与与分​​子基础有关的新型转录组观测 人类中的脉络膜巨噬细胞，表明它们具有稳健的抗炎作用并表达了几种 脂质间隙涉及的关键模块。值得注意的是触发受体在髓样中表达的表达 细胞2（Trem2），一种介导脂质稳态和免疫抑制的脂质受体 并且在几种疾病中丢失，涉及细胞外材料的积累。使用小鼠的脉络组织， 我们员工的各种技术来验证与脉络膜巨噬细胞有关的关键发现。我们表明 脉络膜巨噬细胞对于在慢性脂质时期保持脉络膜中的脂质体内稳态很重要 挑战，随着这些细胞的扩展并包含9周高脂饮食后几乎所有过量的脂质。这些 调查结果使我们提出了核心假设，即trem2+脉络膜巨噬细胞调节脂质稳态 RPE/脉络膜和抑制注射和脉络膜新生血管形成。我们建议使用TREM2的两个目标 敲除小鼠以询问trem2信号在脉络膜巨噬细胞中的作用相对于脂质 RPE/脉络膜中的代谢，免疫和新生血管抑制。我们期待这一点 提案将扩大我们对脉络膜巨噬细胞在脉络膜生态系统中的作用的理解，并将 将TREM2识别为AMD中的新药物靶标。 PI的拟议培训计划塞思·福特曼（Seth Fortmann）由他的导师玛丽亚·格兰特（Maria Grant）博士赞助。 培训计划的总体目标是为PI为成功的职业提供强大的科学基础 作为身体科学家眼科医生。培训计划中包括将有助于PI的经验：1） 在各种技术中获得能力 人类捐赠者眼睛的体内成像； 2）开发假设驱动的研究； 3）在口头和 书面格式； 4）有效地将研究与诊所整合在一起； 5）与其他科学家合作；和6） 负责任的行为研究。