EBF2 determines and maintains brown adipocyte identity
ABSTRACT: We compared PPARg binding sites in BAT and eWAT to identify regulatory elements that contribute to BAT identity and to find an important factor that bind those elements. To this end, we performed PPARg ChIP-seq in both tissues and called each tissue-spsecific binding sites. PPARg ChIP-seq in BAT and eWAT of mice
Project description:We compared PPARg binding sites in BAT and eWAT to identify regulatory elements that contribute to BAT identity and to find an important factor that bind those elements. To this end, we performed PPARg ChIP-seq in both tissues and called each tissue-spsecific binding sites. Overall design: PPARg ChIP-seq in BAT and eWAT of mice
Project description:Obesity has become a global health problem. Brown adipose tissue (BAT), specialized for energy expenditure through thermogenesis, potently counteracts obesity. Recently, BAT is also identified in human adults. We found that Lgr4 homozygous mutant (Lgr4m/m) mice display reduced adiposity and exhibit brown-like adipocytes in their WAT depots with higher expression of uncoupling protein 1 (Ucp1). Furthermore, Lgr4 ablation potentiates brown adipocyte differentiation from stromal vascular fraction (SVF) of epididymal WAT (eWAT) in vitro. We used microarrays to emxamine the gene expression profiles of the brown-like adipocytes differentiated from SVF of wild-type and Lgr4 mutant mice. We identified distinct gene expression profiles of these two groups. To demonstrate Lgr4 ablation can potentiate the differentiation of SVF from eWAT toward brown-like adipocytes in vitro, we isolated SVF from epididymal white adipose tissue (eWAT) of wild-type (WT) and Lgr4 mutant mice. We then plated SVF cells in 12-well plate, and differentiated them to brown adipocytes, followed by RNA extraction and hybridization with Affymetrix microarrays.
Project description:DNA hydroxymethylation plays a crucial role in the regulation of gene transcription. In this study, using hMeDIP-seq experiment, we report the mapping of DNA hydroxymethylation in adipocytes from mouse eWAT Examination of DNA hydroxymethylation pattern in adipocytes from mouse eWAT
Project description:Genome-wide comparisons of transcription factor binding sites in different species allow for a direct evaluation of the evolutionary constraints that shape transcription factor binding landscapes. To gain insights into the evolution of the PPARg-dependent transcriptional network, we obtained binding data for PPARg, RXR and PU.1 in human macrophages and compared the profiles to matching data from mouse macrophages (Lefterova et al. 2010 (PMID 20176806); GSE21314). We found that PPARg binding was highly divergent and only 5% of the PPARg-bound regions were occupied in both species. Despite the low conservation of PPARg binding sites, conserved PPARg target genes contribute more than 30% to the functional target genes identified in human macrophages. In addition, conserved target genes are strongly enriched for lipid metabolic functions. We detected the lineage-specification factor PU.1 at the majority of human PPARg binding sites. This confirmed the juxtaposed binding configuration found in mouse macrophages and demonstrated the preservation of tissue-specific adjacent PPARg-Pu.1 binding in the absence of individual binding site conservation. Finally, based on this PPARg and PU.1 binding between human and mouse, we suggest a mechanism by which PU.1 facilitates PPARg binding site turnover in macrophages. Genome-wide location analysis for 3 transcription factors (PPARg, RXR and PU.1) in a human monocytic cell line (THP-1). This submission represents the human binding data component of the study.
Project description:This program addresses the gene signature associated with the development of type 2 diabetes in the db/db mice. Specifically, which genes are differentially expressed in adipose tissue of the db/db mice compared to the control db/+ mice? The db/db mice eWAT profiling data was analyzed by identifying genes that were up- and down-regulated at selected p value and fold change in the eWAT of db/db mice compared to the corresponding db/+ controls.
Project description:Prdm16 is a transcription factor that drives a complete program of brown adipocyte differentiation, but the mechanism by which Prdm16 activates gene transcription remains unknown. Utilizing ChIP-seq teqhnique, we found that Prdm16 binds to chromatin at/near many brown fat-selective genes in BAT. Interestingly, Prdm16-deficiency dramatically reduced the binding of Med1 to Prdm16-target sites. Indeed, Prdm16 binds and recruits Med1 to BAT-enriched genes and the loss of Prdm16 caused a fundamental change in chromatin architecture at key BAT-selective genes and also reduced transcirptional activity. Moreover, Prdm16, through its interaction with Med1, defines and regulates the activity of super-enhancers that drive the expression of cell identity genes. Together, these data demonstrate that Prdm16 drives gene transcription by recruiting Med1 to control chromatin architecture and super-enhancers. Brown adipose tissues were collected from Prdm16 knockout and wiletype 9-month-old mice and ChIP-seq was performed for Prdm16, PolII, Med1, and H3K27ac.
Project description:hASC pre-adipocyte cells were grown to confluence and induced to differentiate in adipogenic media. Examination of 6 histone modifications and CTCF at 4 time points and PPARG at 1 time point using ChIP-Seq
Project description:3T3-L1 pre-adipocyte cells were grown to confluence and induced to differentiate in adipogenic media. Examination of 6 histone modifications and CTCF at 4 time points and PPARG at 1 time point using ChIP-Seq
Project description:Objective: Procyanidins are polyphenolic bioactive compounds that exert beneficial effects against obesity and its related diseases. The aim of this study was to evaluate whether the supplementation with low doses of a grape seed procyanidin extract (GSPE) to dams during pre and postnatal periods has biological effects on their offspring at youth. Design: The metabolic imprinting effect of GSPE was evaluated in 30 days-old male offspring of four groups of rats that were fed either a standard diet (STD) or a high-fat diet (HFD) and supplemented with either GSPE at 25 mg per kg of body weight/day or vehicle during pregnancy and lactation. Results: A significant increase in the adiposity index and in the weight of all the white adipose tissue depots studied (retroperitoneal –RWAT-, mesenteric –MWAT-, epididymal –EWAT- and inguinal –IWAT-) was observed in offspring of dams fed with a HFD and treated with GSPE (HFT group), compared to the offspring of dams fed with the same diet and that do not received procyanidins (HF group). HFT animals also showed a higher number of cells in the EWAT, a sharply decrease of the circulating levels of monocyte chemoattractant protein-1 (MCP-1) as well as a moderate, but significant, decrease of plasma glycerol levels. The transcriptomic analysis performed in the EWAT showed 238 genes differentially expressed between HF and HFT animals, covering an entire range of processes related with the immune function and the inflammatory response (the metabolic pathway mainly reflected in the EWAT), adipose tissue remodeling and function, lipid and glucose homeostasis and metabolism of methyl groups. Conclusion: GSPE treatment to dams fed a HFD during pregnancy and lactation increases adiposity, decreases the circulating levels of MCP-1 and modulates the expression of key genes involved in the adipose tissue metabolism of their offspring. The microarray study was performed with the EWAT RNA samples of rats from the HF and the HFT groups (n=8 animals each).
Project description:Robust identification of placental PPARg target genes via mutliple PPARg-dependence criteria. Integration of differential expression data from Pparg-null, Rxra-null, Med1-nul and Ncoa6-null placentas and from WT and Pparg-null Trophoblast stem cells (TSC) differentiated for 2 or 4 days in the presence or absence of the PPARg agonist Rosiglitazone (Rosi). [Placentas] Three pools of three WT placentas, each vs a litter-matched pool of three Pparg-null placentas Three pools of three WT placentas, each vs a litter-matched pool of three Rxra-null placentas Three pools of three WT placentas, each vs a litter-matched pool of three Med1-null placentas Three pools of three WT placentas, each vs a litter-matched pool of three Ncoa6-null placentas [Trophoblast stem cells (TSC)] Three independent WT TSC lines differentiated for two and four days in the presence or absence of Rosi vs two independent Pparg-null TSC lines differntiated for the same durations in the presence of Rosi