Inhibition of AXL Receptor Tyrosine Kinase Enhances Brown Adipose Tissue Functionality in mice [HiSeq]
Ontology highlight
ABSTRACT: To identify transcriptomic differences in interscapular brown adipose tissue depots from HFD-challenged wild-type (WT) vs. Axl KO (whole-body Axl Receptor knockout) mice
Project description:The interscapular brown adipose tissue (BAT) depots of adult male and female C57BL/6J mice, housed at 22 °C, were analyzed to identify sex differences in the BAT transcriptome at basal housing conditions.
Project description:Brown adipose tissue is a specialized fat tissue involved in heat generation by using a process termed thermogenesis. This ability to convert nutrient energy into heat sets brown adipocytes apart from the more common type of white adipocytes, which are mainly involved in energy storage. Brown adipose depots occur as a large interscapular depot in mice. Brown adipocytes are multilocular, i.e. contain many small lipid-filled vacuoles and uniquely express the uncoupling protein 1. In this study, the gene expression patterns in brown adipose tissue samples of young, healthy mice was analyzed.
Project description:Brown fat generates heat via the mitochondrial uncoupling protein UCP1, defending against hypothermia and obesity. Recent data suggest that there are two distinct types of brown fat: classical brown fat derived from a myf-5 cellular lineage and UCP1-positive cells that emerge in white fat from a non-myf-5 lineage. Here, we report the isolation of “beige” cells from murine white fat depots. Microarray analysis of the differentiated clonal inguinal and interscapular adipocytes in the presence of forskolin (10mM). These samples were profiled using Affymetrix mouse 430 2.0 arrays, 26 samples in total.
Project description:Thoracic perivascular adipose tissue (PVAT) is a unique adipose depot that likely influences vascular function and susceptibility to pathogenesis in obesity and metabolic syndrome. Surprisingly, PVAT has been reported to share characteristics of both brown and white adipose, but a detailed direct comparison to interscapular brown adipose tissue (BAT) has not been performed. Here we show by full genome DNA microarray analysis that global gene expression profiles of PVAT are virtually identical to BAT, with equally high expression of Ucp-1, Cidea and other genes known to be uniquely or very highly expressed in BAT. PVAT and BAT also displayed nearly identical phenotypes upon immunohistochemical analysis, and electron microscopy confirmed that PVAT contained multilocular lipid droplets and abundant mitochondria. Compared to white adipose tissue (WAT), PVAT and BAT from C57BL/6 mice fed a high fat diet for 13 weeks had markedly lower expression of immune cell-enriched mRNAs, suggesting resistance to obesity-induced inflammation. Indeed, staining of BAT and PVAT for macrophage markers (F4/80, CD68) in obese mice showed virtually no macrophage infiltration, and FACS analysis of BAT confirmed the presence of very few CD11b+/CD11c+ macrophages in BAT (1.0%) in comparison to WAT (31%). In summary, murine PVAT from the thoracic aorta is virtually identical to interscapular BAT, is resistant to diet-induced macrophage infiltration, and thus may play an important role in protecting the vascular bed from thermal and inflammatory stress. 8-week-old male C57BL6/J mice were fed a normal (ND) or high fat diet (HFD) (Research Diets 12451, 45 kcal% fat) for 13 weeks. Mice were then euthanized and four different adipose depots were harvested for RNA analysis: perivascular fat from the lesser curvature of the aortic arch (PVAT), interscapular brown adipose (BAT), inguinal adipose tissue (SAT), and epididymal adipose tissue (VAT). 250 ng total RNA pooled from two mice was used for cDNA synthesis; 3 biological replicates per tissue and diet were performed for a total of 24 hybridizations.
Project description:We analyzed coding transcript abundance in primary, immortalized brown preadipocytes from murine, interscapular brown adipose tissue.