Spatial context of adipose tissue macrophages in obesity

肥胖症中脂肪组织巨噬细胞的空间背景

• 批准号: 10287708
• 负责人: Lindsey Allison Muir
• 金额: $ 11.7万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10287708
• 关键词: Address; Adipocytes; Adipose tissue; Anatomy; Apoptotic; Architecture; Biogenesis; Biological Assay; Cardiovascular Diseases; Cells; Cessation of life; Chronic; Data; Dental crowns; Development; Diabetes Mellitus; Disease; Foundations; Functional disorder; Gene Expression; Gene Expression Profile; Goals; Health; Human; ITGAX gene; Image; Immune; Immune system; Inflammation; Insulin Resistance; Investigation; Knowledge; Link; Lipids; Location; Lysosomes; Macrophage Activation; Maps; Mediator of activation protein; Metabolic; Metabolic Diseases; Metabolic dysfunction; Metabolism; Methods; Modeling; Molecular Profiling; Morbidity - disease rate; Mus; Myeloid Cells; Obesity; Obesity associated disease; Overweight; Physiological; Production; Publishing; Research; Resolution; Risk; Role; Signal Transduction; Solid; Stains; Stress; Structure; Techniques; Time; Tissue Expansion; Tissues; United States; Work; cohort; cost; cytokine; genome-wide; in vivo; macrophage; mouse model; new therapeutic target; novel strategies; preservation; programs; scavenger receptor; spatial relationship; transcriptome sequencing; transcriptomics

PROJECT SUMMARY Adipose tissue inflammation is a known link between obesity and metabolic dysfunction and is associated with accumulation of adipose tissue macrophages (ATM). However, the interplay between ATMs and obese tissue inflammation and tissue expansion is still not well understood. Unbiased techniques such as RNA-sequencing of whole tissue or single cells have been extremely useful in characterizing adipose tissue cellular changes with obesity, though these methods lose anatomical context. The fine detail of tissue architecture and ATMs within their anatomical niche is a critical aspect of understanding their function in vivo, but methods such as immunolabeling can only detect a small subset of known markers and structures. Here I propose to use the recently available method of spatial transcriptomics (STX) to capture gene expression signatures across adipose tissue, retaining anatomical context of cell signatures and near single cell resolution. My preliminary data validate the feasibility of this approach for adipose tissue and identify lysosomal signatures in scavenger receptor high (SRhi) ATMs as a high priority target for investigation in obesity and diabetes. In conjunction with STX, I will perform single cell transcriptomics to delineate representative ATM and adipocyte signatures, which I will use to generate spatial maps of ATM-adipocyte niches during obesity. My overall goal is to map SRhi and SRlo ATM niches within adipose tissue in metabolic dysfunction. My central hypothesis is that dysfunctional lysosomal processing during SRlo ATM clearance of dying adipocytes precedes internal lipid accumulation and aggregation into proinflammatory crown-like structures (CLS). To examine this hypothesis, I will investigate ATMs and adipocytes in STX and single cell transcriptomics data and ATM lysosomal function in a time course of murine obesity. My research aims are: (1) Identify ATM niches and their lysosomal signatures in obese adipose tissue. I will examine the hypothesis that the anatomical niche of SRlo ATMs promotes lysosomal stress during interface with apoptotic adipocytes prior to CLS formation. Single cell transcriptomics will enable identification of prominent ATM subsets across the time course, and I will map these signatures to specific anatomical locations within adipose tissue. (2) Determine lysosomal function, lipid accumulation, and proinflammatory cytokine production in SRhi and SRlo ATMs. I will examine the hypothesis with increased duration of obesity, lysosomal stress in SRlo ATMs associates with lipid accumulation and production of proinflammatory mediators prior to development of insulin resistance. To determine lysosomal signatures and function, lipid-laden vs. lipid-lo ATMs from the time course will be examined through bulk RNA-sequencing, lysosomal staining and quantification, and assays to identify mediators of lysosomal stress and lipid accumulation. The proposed work develops a new line of my research focusing on a murine model of obesity, paralleling my human K01 work. Together, these projects will provide a solid foundation for my independent research program and preliminary data toward an R01 application within two years.

项目摘要 脂肪组织炎症是肥胖和代谢功能障碍之间的已知联系，与 脂肪组织巨噬细胞的积累（ATM）。但是，ATM和肥胖组织之间的相互作用 炎症和组织扩张仍然不太了解。公正的技术，例如RNA序列 整个组织或单个细胞的表征脂肪组织细胞变化非常有用 肥胖，尽管这些方法失去了解剖环境。组织结构和自动取款机的细节 他们的解剖学利基是理解其在体内功能的关键方面，但是诸如 免疫标记只能检测到一小部分已知标记和结构。在这里我建议使用 最近可用的空间转录组学方法（STX）捕获脂肪跨越基因表达的特征 组织，保留细胞特征的解剖环境和接近单细胞的分辨率。我的初步数据验证 这种方法对于脂肪组织的可行性并鉴定清道夫受体中的溶酶体特征 （SRHI）ATM作为肥胖和糖尿病研究的高优先级目标。与STX结合，我将 执行单细胞转录组学以描述代表性的ATM和脂肪细胞特征，我将使用它们 在肥胖期间生成ATM-脂肪细胞生态位的空间图。我的总体目标是映射SRHI和SRLO ATM 代谢功能障碍中脂肪组织内的壁ni。我的中心假设是功能失调的溶酶体 垂死脂肪细胞的SRLO ATM清除期间的加工前脂质内部脂质积累和聚集 进入促炎性冠状结构（CLS）。为了审查这一假设，我将研究ATM和 在鼠的时间过程中，STX和单细胞转录组数据和ATM溶酶体功能的脂肪细胞 肥胖。我的研究目的是：（1）确定肥胖脂肪组织中的ATM生态位及其溶酶体特征。 我将研究以下假设：SRLO ATMS的解剖壁基促进界面期间的溶酶体应力 在CLS形成之前与凋亡脂肪细胞。单细胞转录组学将使显着识别 在整个时间课程中的ATM子集，我将这些签名映射到特定的解剖位置 脂肪组织。 （2）确定溶酶体功能，脂质积累和促炎细胞因子的产生 在SRHI和SRLO ATMS中。我将随着肥胖持续时间，SRLO中的溶酶体应激的持续时间增加的假设 在开发之前 胰岛素抵抗。为了确定溶酶体特征和功能，从脂质含量和脂质-LO ATM开始 课程将通过大量RNA测序，溶酶体染色和定量进行检查，并进行测定 鉴定溶酶体应激和脂质积累的介体。拟议的工作开发了我的新系列 研究重点是肥胖模型，与我的人类K01工作相似。这些项目将在一起 为我的独立研究计划提供坚实的基础，并向R01应用程序提供初步数据 在两年内。