The Role of Perilipin 2 in Macrophages after Experimental Spinal Cord Injury

Perilipin 2 在实验性脊髓损伤后巨噬细胞中的作用

• 批准号: 10535630
• 负责人: Ethan Phares Glaser
• 金额: $ 5.17万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-09 至 2026-08-08
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10535630
• 关键词: Ablation; Acute; Alzheimer' s Disease; Arterial Fatty Streak; Atherosclerosis; Bone Marrow; Cells; Cholesterol; Cholesterol Homeostasis; Chronic; Cirrhosis; Code; Custom; Cytosol; Data; Disease; Environment; Enzyme-Linked Immunosorbent Assay; Enzymes; Extramural Activities; Family; Fluorescent in Situ Hybridization; Foam Cells; Foundations; Functional disorder; Gene Expression; Genes; Genetic; Grant; Health Care Costs; Immunofluorescence Immunologic; In Vitro; Individual; Inflammation; Inflammatory; Injury; Interleukin-1 beta; Interleukin-6; Lesion; Leukocytes; Lipid-Laden Macrophage; Lipids; Locomotor Recovery; Mediating; Metabolism; Microscopy; Modeling; Morphology; Motor; Mus; Myelin; Myeloid Cells; Nervous System Trauma; Paralysed; Pathology; Pathway interactions; Phagocytosis; Phenotype; Physicians; Process; Production; Publishing; Quantitative Reverse Transcriptase PCR; Recovery; Recovery of Function; Research Support; Role; Scientist; Sensory; Site; Sorting - Cell Movement; Spinal Cord; Spinal cord injury; Stains; Stimulus; System; Testing; Time; Tissues; Training; Transgenic Model; Up-Regulation; Western Blotting; Work; collected works; cytokine; design; experimental study; histological stains; improved; in vitro Model; injured; injury recovery; insight; lipid metabolism; macrophage; molecular sequence database; monocyte; mouse model; nano-string; neuroinflammation; new therapeutic target; non-alcoholic; nonalcoholic steatohepatitis; novel; perilipin; prevent; repaired; research data dissemination; response; responsible research conduct; single-cell RNA sequencing; therapeutic target; uptake

PROJECT SUMMARY/ABSTRACT Spinal cord injury (SCI) leads to permanent motor and sensory loss that is exacerbated by persistent inflammation months after the injury. After SCI, monocyte-derived macrophages (MDMs) infiltrate the lesion to aid in cellular debris clearance. However, this response is emerging as a double- edged sword. Lingering debris inhibits repair and plasticity while clearance of the debris by infiltrating MDMs induces a proinflammatory and damaging phenotype. Clearance of cholesterol-rich myelin debris causes MDMs to resemble proinflammatory foam cells both phenotypically and morphologically. Foam cells are lipid- laden macrophages with numerous lipid droplets (LDs) that form when excessive cholesterol uptake overwhelms cholesterol metabolism. Foam cells also drive chronic inflammation in atherosclerosis and non- alcoholic steatohepatitis (NASH). Foam cells persist chronically in the injured cord and may contribute to the sustained proinflammatory lesion environment. However, their role in the chronic inflammatory state is poorly understood. Therefore, elucidating the effect of foam cell formation after SCI is integral to understanding the contribution of MDMs to injury pathology. Preliminary and published data identify Perilipin 2 (Plin2) as a key differentially upregulated gene in both infiltrating MDMs after SCI and foam cells in atherosclerosis. Plin2 is essential in regulating the formation and storage of cholesterol (i.e., lipid droplets (LDs)) in macrophages as lipid metabolites are either exported from these cells or stored in LDs. Plin2 coats LDs, sequesters them in the cytosol and prevents lipolytic enzymes from accessing their cargo. Reducing Plin2, may, therefore, reduce LD accumulation and mitigate foam cell formation after SCI. In models of atherosclerosis and NASH, Plin2 deficient mice produced fewer foam cells and were protected from atherosclerotic plaque formation and cirrhosis, respectively. To understand the effects of Plin2 upregulation in MDMs after SCI a novel targeted deletion of Plin2 using a LysMCre/lox system will be employed. Using this mouse model, this project will determine (1) the role of Plin2 in myelin-induced foam cell formation using an in vitro approach and (2) the effects of targeted Plin2 deletion in MDMs on foam cell formation, inflammation, and locomotor recovery after experimental. These experiments will test the hypothesis that cell-specific Plin2 ablation in MDMs suppresses foam cell formation after SCI, inhibits inflammation, and promotes functional recovery. If successful, this project will provide novel insight into how CNS macrophages metabolize myelin and may provide new therapeutic targets to improve SCI recovery by resolving chronic intraspinal inflammation. Through the completion of this training grant, the PI will receive ample training regarding the implementation of project management, responsible conduct of research, and the dissemination of findings. This training will provide the PI with the skillset necessary to carry out the specific aims and lay the foundation for the PI to become an independent physician-scientist with an extramurally supported research portfolio in the field of neurotrauma.

项目摘要/摘要脊髓损伤(SCI)会导致永久性运动和感觉丧失，即 受伤几个月后持续发炎加重。脊髓损伤后单核细胞来源的巨噬细胞 (MDMS)渗透到病变中，以帮助清除细胞碎片。然而，这种反应正在成为一个双重的- 锋利的剑。残留的碎片在通过渗透MDM清除碎片时抑制修复和可塑性 导致促炎和破坏性的表型。清除富含胆固醇的髓鞘碎片导致 MDMS在表型和形态上都类似于炎性泡沫细胞。泡沫细胞是脂类- 巨噬细胞在过度摄取胆固醇时形成大量脂滴(LDs) 压倒胆固醇代谢。泡沫细胞也推动动脉粥样硬化和非动脉粥样硬化患者的慢性炎症 酒精性脂肪性肝炎(NASH)泡沫细胞在损伤的脊髓中持续存在，并可能参与了 持续的促炎损伤环境。然而，它们在慢性炎症状态中的作用很差。 明白了。因此，阐明脊髓损伤后泡沫细胞形成的影响是理解脊髓损伤后 MDM在损伤病理学中的贡献。初步和已发表的数据确定Perilipin 2(Plin2)是关键 脊髓损伤后浸润性巨噬细胞和动脉粥样硬化中泡沫细胞的差异表达基因。Plin2是 在调节巨噬细胞中胆固醇(即脂滴)的形成和储存中起重要作用 脂质代谢产物要么从这些细胞输出，要么储存在LDS中。Plin2将LDS包裹起来，将它们隔离在 细胞溶质，并防止脂解酶进入其货物。因此，降低Plin2可能会降低LD 减少脊髓损伤后泡沫细胞的堆积和形成。在动脉粥样硬化和NASH模型中，Plin2 缺陷小鼠产生较少的泡沫细胞，并防止动脉粥样硬化斑块的形成和 分别为肝硬变。了解脊髓损伤后MDM中Plin2表达上调的作用 将使用LysMCre/LOX系统删除Plin2。使用这个鼠标模型，这个项目将 用体外方法确定(1)Plin2在髓鞘诱导的泡沫细胞形成中的作用和(2) MDM中靶向Plin2缺失对泡沫细胞形成、炎症和运动功能恢复的影响 试验性的。这些实验将检验MDM细胞特异性Plin2消融抑制MDM的假设 脊髓损伤后泡沫细胞的形成，抑制炎症，促进功能恢复。如果成功，这个项目 将为研究中枢神经系统巨噬细胞如何代谢髓鞘提供新的见解，并可能提供新的治疗方法 通过解决慢性椎管内炎症来提高脊髓损伤恢复的目标。通过完成这项工作 培训补助金后，主计长将接受关于实施项目管理的充分培训， 负责任地开展研究，传播研究成果。该培训将为私家侦探提供 执行特定目标所需的技能，并为PI成为独立的 内科医生-科学家，在神经创伤领域拥有一项得到外部支持的研究组合。