Real Time Visualization of Obesity-Induced Inflammation in Adipose Tissue

描述（由申请人提供）：肥胖诱导的炎症在肥胖与心血管疾病和2型糖尿病等疾病之间的联系中起着重要作用。这背后的机制与脂肪组织中广泛存在的白细胞有关，这些白细胞分泌许多炎症介质。自从最初在脂肪中识别出巨噬细胞以来，脂肪中存在的白细胞类型的数量大大增加，现在包括大多数白细胞类型。不幸的是，缺乏对这些细胞如何相互作用以及与脂肪细胞相互作用的综合理解，限制了该领域的进展。我们认为，我们理解上的这种差距在很大程度上是由于可用于测定脂肪中炎症细胞的技术有限。此外，我们认为有许多动态的细胞事件发生在脂肪中，但没有被捕获。因此，本研究的目标是设计和实施一种新的方法，在肥胖小鼠模型的脂肪组织活体显微镜。能够观察脂肪中白细胞的相互作用可以揭示肥胖炎症启动和维持的机制。这一进展将是重要的，因为它有可能解开肥胖中炎症是如何产生的谜团。我们将通过完成两个目标来实现我们的目标。(1)建立脂肪组织白细胞活体显像方法。这将采用双光子共聚焦显微镜来生成活体动物脂肪的4D视图。(2)探讨肥胖对T细胞迁移与脂肪相关淋巴簇（FAT-associated lymphoid clusters，PBMC）的关系。我们将使用活体显微镜检查来测试肥胖诱导的T细胞流出PBMC并进入脂肪以产生炎症的模型。在项目结束时，我们希望为肥胖研究人员提供一种新的标准化工具，可以生成新的模型，并为脂肪组织基质细胞的动态特性提供一个窗口。

DESCRIPTION (provided by applicant): Obesity-induced inflammation plays an important role in the link between obesity and diseases such as cardiovascular disease and type 2 diabetes. The mechanism behind this relates to the wide range leukocytes found in adipose tissue that secrete numerous inflammatory mediators. Since the initial identification of macrophages in fat, the number of leukocyte types present in fat have greatly increased and now include most leukocyte types. Unfortunately, an integrated understanding of how these cells interact with each other and with adipocytes is lacking and limits progress in the field. We feel that this gap in our understanding is due in large part to the limited techniques available to assay inflammatory cells in fat. Furthermore, we feel that there are many dynamic cellular events that are occurring in fat but are not being captured. Therefore, the goal of this study is to design and implement a novel methodology for intravital microscopy on adipose tissue in mouse models of obesity. Being able to observe leukocyte interactions in fat can reveal the mechanisms involved in the initiation and maintenance of inflammation in obesity. This advance will be significant as it has the potential to unlock the mystery of how inflammation is generated in obesity. We will accomplish our goal by completing two aims. (1) To establish the methodology for intravital imaging of leukocytes in adipose tissue. This will employ two-photon confocal microscopy to generate 4D views of fat in live animals. (2) To evaluate the effects of obesity on T cell migration in relation to fat associated lymphoid clusters (FALCs). We will use intravital microscopy to test a model of obesity-induced induction of T cell flux out of FALCs and into fat to generate inflammation. At the end of the project, we hope to generate a new standardized tool for obesity researchers that can generate new models and provide a window into the dynamic properties of adipose tissue stromal cells.