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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要脂肪组织炎症是肥胖和代谢功能障碍之间已知的联系，并且与脂肪组织巨噬细胞（ATM）的积累。然而，ATM 机和肥胖组织之间的相互作用炎症和组织扩张仍不清楚。无偏见的技术，例如 RNA 测序整个组织或单个细胞在表征脂肪组织细胞变化方面非常有用肥胖，尽管这些方法失去了解剖学背景。内部组织架构和 ATM 的精细细节它们的解剖学生态位是理解它们体内功能的一个关键方面，但是诸如免疫标记只能检测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（STX）方法来捕获跨脂肪的基因表达特征组织，保留细胞特征的解剖背景和接近单细胞的分辨率。我的初步数据验证这种方法对脂肪组织的可行性并鉴定清道夫受体高溶酶体特征 (SRhi) ATM 是肥胖和糖尿病研究的高度优先目标。与 STX 一起，我将执行单细胞转录组学来描绘代表性 ATM 和脂肪细胞特征，我将用它来生成肥胖期间 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生态位。我的中心假设是功能失调的溶酶体 SRlo ATM 过程中死亡脂肪细胞的清除先于内部脂质积累和聚集转化为促炎冠状结构（CLS）。为了检验这个假设，我将研究 ATM 机 STX 中的脂肪细胞和单细胞转录组学数据以及小鼠随时间进程的 ATM 溶酶体功能肥胖。我的研究目标是：(1) 识别肥胖脂肪组织中的 ATM 生态位及其溶酶体特征。我将研究以下假设：SRlo ATM 的解剖学利基会在界面过程中促进溶酶体应激在 CLS 形成之前与凋亡的脂肪细胞一起。单细胞转录组学将能够识别突出的整个时间过程中的 ATM 子集，我会将这些签名映射到特定的解剖位置脂肪组织。 (2) 测定溶酶体功能、脂质积累和促炎细胞因子的产生在 SRhi 和 SRlo ATM 中。我将检验肥胖持续时间增加、SRlo 中溶酶体应激的假设 ATM 与脂质积累和促炎介质的产生有关，然后再发生胰岛素抵抗。为了确定溶酶体特征和功能，从当时的载脂 ATM 与低脂 ATM 过程将通过大量 RNA 测序、溶酶体染色和定量以及检测来检查确定溶酶体应激和脂质积累的介质。拟议的工作开发了我的新路线研究重点是小鼠肥胖模型，与我的人类 K01 工作类似。这些项目将共同为我的独立研究计划和R01申请的初步数据提供坚实的基础两年内。