Project description:This SuperSeries is composed of the following subset Series: GSE25401: Adipose Tissue MicroRNAs as Regulators of CCL2 Production in Human Obesity [gene expression] GSE25470: Adipose Tissue MicroRNAs as Regulators of CCL2 Production in Human Obesity [miRNA data] GSE25910: Adipose Tissue MicroRNAs as Regulators of CCL2 Production in Human Obesity [differentiation data] Refer to individual Series
Project description:Chronic, low-grade adipose tissue inflammation associated with adipocyte hypertrophy is an important link in the relationship between obesity and insulin resistance. Although ubiquitin ligases are essential regulators of inflammatory processes, the role of these enzymes in metabolically driven adipose tissue inflammation is relatively unexplored. In this study, we found that the ubiquitin ligase Siah2 is a central factor in obesity-related adipose tissue inflammation. When challenged with chronic excess energy intake, Siah2-null mice become obese with enlarged adipocytes, but do not develop obesity-induced insulin resistance. Proinflammatory gene expression is substantially reduced in the Siah2-null epididymal adipose tissue of the obese Siah2KO mice.
Project description:Obesity drives significant changes in adipose tissue that precede development of tissue and systemic insulin resistance. Immune cell infiltration and inflammation are known contributors to these changes but there is limited understanding of their spatial context tissue-wide. We sought to identify spatial patterning in epididymal adipose tissue immune cells in a time course of diet-induced obesity in mice. Using spatial transcriptomics and single-cell RNA-sequencing, we identified dominant cell type signatures preserved in their anatomical context, quantified gene expression patterns at spots throughout adipose tissue, performed cell type network analysis, and investigated ligand-receptor colocalization. Our data support increased innate immune cells, including macrophages, monocytes, and innate lymphoid cells, with tissue-wide interspersion and dampened adaptive immune cell signatures with obesity. Network analysis identified increased heterogeneity in all major immune cell types, consistent with increased subtypes. To capture tissue dynamics at obesity onset, we draw on mathematical principles from linear algebra and spectral graph theory. We provide a framework for better understanding cell cooperation toward emergence of multicellular tissue function. Further, we adapt Turing's mathematical theory on morphogenesis to show lapse of emergence in adipose tissue.
Project description:To assess changes in expression level of various chemokines and their receptors on diet-induced obesity, we analysed gene expression in adipose tissue of C56BL/6J mice fed a high-fat (HF) diet or normal chow diet for 8 weeks. HF diet-induced obese (DIO) mice showed adipose tissue inflammation and insulin resistance. Comprehensive gene expression analysis showed that MCP-1–CCR2 and CCL5–CCR5 signalling in epididymal white adipose tissue (eWAT) were enhanced during the development of obesity. Surprisingly, the gene expression of Cx3cl1 was decreased in the eWAT of DIO mice compared with lean mice. While Cx3cr1 expression showed no significant difference between DIO and lean mice. Decreased CX3CL1-CX3CR1 signalling in adipose tissue may also be involved in the development of obesity-induced adipose tissue inflammation and insulin resistance.
Project description:Different human adipose tissue depots may have functional differences. Subcutaneous human adipose tissue has been extensively studied, but less is known about other depots. Perithyroid (PT) adipose tissue contains not only white adipocytes but also brown adipocytes. The aim of this study was to compare the expression of brown adipocyte containing perithyroid adipose tissue with s.c. adipose tissue.role in the development of obesity. Expression profiling of adipose tissue may give insights into mechanisms contributing to obesity and obesity-related disorders. Expression analysis of paired biopsies from s.c and perithyriod (PT) adipose tissue from nine subjects undergoing surgery in the thyroid region.
Project description:Different human adipose tissue depots may have functional differences. Subcutaneous human adipose tissue has been extensively studied, but less is known about other depots. Perithyroid (PT) adipose tissue contains not only white adipocytes but also brown adipocytes. The aim of this study was to compare the expression of brown adipocyte containing perithyroid adipose tissue with s.c. adipose tissue.role in the development of obesity. Expression profiling of adipose tissue may give insights into mechanisms contributing to obesity and obesity-related disorders.
Project description:Chronic low-grade visceral white adipose tissue (WAT) inflammation is a hallmark of metabolic syndrome in obesity. Here, we demonstrate that a subpopulation of adipose tissue perivascular (PDGFRb+) cells, termed “fibro-inflammatory progenitors” (FIPs), activate pro-inflammatory signaling cascades shortly after the onset of high-fat diet feeding of mice and regulate pro-inflammatory macrophage accumulation in WAT in a TLR4-dependent manner. FIPs activation in obesity is mediated by the downregulation of ZFP423, identified here as a transcriptional co-regulator of NFkB. Biochemical analysis of ZFP423-protein complexes and ChIP-seq analysis reveal that ZFP423 suppresses the DNA-binding capacity of the p65 subunit of NFkB by inducing a p300 to NuRD co-regulator switch. Doxycycline-inducible expression of Zfp423 in PDGFRb+ cells suppresses inflammatory signaling in FIPs and attenuates metabolic inflammation of visceral WAT in obesity. Inducible inactivation of Zfp423 in PDGFRb+ cells increases FIP activity, exacerbates adipose macrophage accrual, and promotes WAT dysfunction. These studies implicate perivascular mesenchymal cells as important regulators of chronic adipose tissue inflammation in obesity and identify ZFP423 as a transcriptional break on NFkB signaling.