ChIP-seq based genome wide profiling of the histone mark H3K27ac and transcription factor Nuclear Factor 1 (NFI) in a differentiating murine brown preadipocyte cell line (IBA)
ABSTRACT: ChIP sequencing was used to generate genome-wide maps of the histone mark H3K27ac during in vitro differentiation of a murine brown preadipocyte cell line (IBA) at five different time points, in two biological replicates: Day 0 (confluence), 2h (post induction), Day 1, Day 2 and Day 4 (mature brown adipocytes). Additionally, transcription factor (TF) localisation maps of the Nuclear Factor 1 (NFI) were generated using ChIP sequencing at two time points: Day 0 and Day 4.
Brown adipocytes regulate energy expenditure via mitochondrial uncoupling, which makes them attractive therapeutic targets to tackle obesity. However, the regulatory mechanisms underlying brown adipogenesis are still poorly understood. To address this, we profiled the transcriptome and chromatin state during mouse brown fat cell differentiation, revealing extensive gene expression changes and chromatin remodeling, especially during the first day post-differentiation. To identify putatively causa ...[more]
Project description:mRNA-sequencing was used to profile temporal changes in gene expression during in vitro differentiation of IBA at five different time points: Day 0 (confluence), 2h (post induction), Day 1, Day 2 and Day 4 (mature brown adipocytes), performed in two biological replicates (with two technical replicates in the first biological replicate).
Project description:Loss of function assays were performed in differentiating IBAs using short hairpin RNAs (shRNAs) against a set of candidate transcription factors: NFIA, DBP, HOXA4, ZFP467, SOX18, ELF3, YBX2 and PPARa. Gene expression profiles of the perturbed and non perturbed (controls including non transduced cells, cells transduced with scrambled and GFP constructs) transcriptomes were measured at Day 6 of differentiation using a novel multiplex, bulk mRNA-seq barcoding method which employs a 3' sequencing approach. This method allowed the measurement of the deviation of the perturbed transcriptome from the non-perturbed transcriptome.
Project description:Enhancers play a central role in cell-type-specific gene expression and are marked by H3K4me1/2. Active enhancers are further marked by H3K27ac. However, the methyltransferases responsible for the deposition of H3K4me1/2 on enhancers remain elusive. Furthermore, the functions of these methyltransferases on enhancers and associated cell-type-specific gene expression are poorly understood. Here, we identify MLL4 (KMT2D) as a major H3K4 mono- and di-methyltransferase in mammalian cells. Using adipogenesis and myogenesis as model systems, we show that MLL4 exhibits cell-type- and differentiation-stage-specific genomic binding and is predominantly localized on enhancers. MLL4 co-localizes with lineage-determining transcription factors (TFs) on active enhancers during differentiation. Deletion of MLL4 dramatically decreases H3K4me1/2 and H3K27ac on enhancers and leads to severe defects in cell-type-specific gene expression and cell differentiation. Finally, we provide evidence that lineage-determining TFs recruit and require MLL4 to establish enhancers critical for cell-type-specific gene expression. Together, these results identify MLL4 as an H3K4 mono-/di-methyltransferase required for enhancer activation during cell differentiation. ChIP-Seq analyses of histone modifications (H3K4me1, H3K4me2, H3K4me3, and H3K27ac) at D0 (day 0) and D2 (day 2) of adipogenesis in WT (MLL3-/-) and MLL4 KO (MLL3-/-;MLL4-/-) brown preadipocytes.
Project description:Insulin is a potent regulator of protein metabolism. Here we describe a time-resolved map of insulin-regulated protein turnover in 3T3-L1 adipocytes using metabolic pulse-chase labelling and high-resolution mass spectrometry.
Project description:Here we have characterized the transcriptional processes underlying the formation of human brown in white (i.e. brite) adipocytes using a genome-wide approach. We show that the browning process is associated with reprogramming of peroxisome proliferator-activated receptor γ (PPARγ) binding to form brite adipocyte-selective PPARγ super-enhancers that appear to play a key role in activation of brite adipocyte-selective genes. We identify the KLF11 gene based on its association with a PPARγ super-enhancer and show that KLF11 is a novel browning factor directly induced by rosiglitazone and required for the activation of brite adipocyte-selective gene program by rosiglitazone. Genome-wide profiling of Dnase I hypersenstive (DHS) sites, epigenomic marks, transcription factor and co-factor binding, and gene expression in hMADS white and brite adipocytes
Project description:In this study we aimed to gain further insight on the role of GCs in adipocyte differentiation. For the future drugability of candidate targets it is of utmost importance to find factors relevant to human biology. Thus, we analyzed the transcriptome of GC induced primary human adipose stem cells (hASC) to identify novel factors downstream of GC action We used microarrays to detail the global programme of gene expression following glucocorticoid treatment and identified distinct classes of up- and downregulated genes during this process. Human preadipocytes (human adipose stem cells) were obtained from lipoaspirates by enzamytic digestions, followed by several steps of centrifugations (Mikkelsen et. al Cell. 2010 Oct 1;143(1):156-69.). Following isolation, human adipose stem cells were transfected with a control siRNA (siCtrl) or two different siRNA oligos targeting the gene LMO3 (siLMO3_oligo1 or siLMO3_oligo2). 40Hrs later, the transfected human adipose stem cells were induced to differentiate into mature adipocytes with a adipogenic cocktail (FullMix) and RNA isolated at day 0 or day6 after induction of differentiation.
Project description:Tightly controlled gene expression orchestrated by the transcription factor p63 during epithelial differentiation is important for development of epithelial-related structures such as epidermis, limb and craniofacial regions. How p63 regulates spatial and temporal expression of its target genes during these developmental processes is however not yet clear. By epigenomics profiling in stem cells established from one of these epithelial structures, the epidermis, we provide a global map of p63-bound regulatory elements that are categorized as single enhancers and clustered enhancers during epidermal differentiation. Transcriptomics analysis shows dynamic gene expression patterns during epidermal differentiation that correlates with the activity of p63-bound enhancers rather than with p63 binding itself. Only a subset of p63-bound enhancers is active in epidermal stem cells, and inactive p63-bound enhancers appear to function in gene regulation during the development of other epithelial tissues. Our data suggest a paradigm that p63 bookmarks genomic loci during the commitment of the epithelial lineage and regulates gene expression in different epithelial tissues through tissue-specific active enhancers. The catalogue of differentially expressed epidermal genes including non-coding RNAs and epithelial enhancers reported here provides a rich resource for studies of epithelial development and related diseases. Different stages of keratinocyte differentiation
Project description:Adipogenesis involves the regulation of hundreds of genes by several well-studied proteins, but the role of long, noncoding RNAs in this process has not been defined. We track the regulation of hundreds of lncRNAs during adipocyte differentiation, and find several that are essential for this process. We extractedbrown and white primary adipocytes and pre-adipocytes and profiled lncRNA expresssion via mRNA-Seq. We also profiled cultured, differentiated adipocytes to verify that we could recapitulate the adipocyte expression profile in preparation for a loss-of-function screen for essential adipogenic lincRNAs.
Project description:Here, we have used digital genomic footprinting to precisely define protein localization for several adipogenic transcription factors at a genome-wide level. In combination with ChIP-seq data, these analyses reveal novel molecular insight into the organization of transcription factors at hotpot regions, which provides a new framework for understanding transcription factor cooperativity on chromatin. Digital genomic footprinting and gene expression in 3T3-L1 pre-adipocytes by high throughput sequencing.