ABSTRACT: SOX6 CUT&RUN on HUDEP1 over expressing SOX6-Flag. The experiment is done using and anti Flag Ab to assist the genome wide binding profile of SOX6 in HUDEP1 (Human Umbilical cord blood-Derived Erythroid Progenitor-1).
Project description:Wnt/β-catenin signaling is a highly organized biochemical cascade that triggers a gene expression program in the signal-receiving cell. The Wnt/β-catenin-driven transcriptional response is involved in virtually all cellular processes during development, homeostasis, and its deregulation causes human disease. However, outstanding questions remain unanswered. A first question concerns cell-specificity: how this response is integrated into lineage-specific choices is still unknown. A second question concerns time: it is not known whether β-catenin associates with its targets simultaneously or in a time-dependent fashion. For instance, while TCF/LEF and other components of the Wnt transcriptional complex are constitutively associated with the chromatin, it is β-catenin arrival, upon Wnt induction, that launches target genes transcription. Therefore, discovering the dynamics of the genome-wide β-catenin binding pattern is required to unambiguously define the direct targets of Wnt signaling To address these questions, we realized a time-resolved atlas of β-catenin genome-wide occupancy in two human cell types, human embryonic kidney cells 293T (HEK293T) and human embryonic stem cells (hESCs). To this end, we treated HEK293T and hESCs with the GSK3 inhibitor/Wnt activator CHIR99021 (10 mM) for 3 days, and assessed β-catenin binding via CUT&RUN-LoV-U (Zambanini et al., 2022) 90 minutes, 4 hours, 24 hours and 3 days after the onset of the stimulation. This approach allowed us to establish that β-catenin repositions to different genomic loci along stimulation time, showing that a definition of Wnt target genes must take into account the time-dimension. Moreover, β-catenin physical targets are largely cell-type specific, as only a subset of them is present across the examined contexts.
Project description:The Wnt/β-catenin signaling pathway plays crucial roles in nearly all parts of embryonic development and adult stem cell homeostasis. Its aberrant activation has been linked to many diseases such as developmental irregularities and various severe forms of cancer, with colorectal cancer (CRC) as a prime example. While much work has been dedicated to uncovering effective therapeutics to block oncogenic Wnt signaling, such interventions have not proven trivial because of the broad activity of Wnt throughout the adult body and the difficulty in finding suitable molecular targets. We have previously identified the developmental transcription factor TBX3 as a participant of the Wnt-mediated transcriptional regulation. Here we examine the genome-wide binding pattern of TBX3 in the human CRC cells lines HCT116 (25 replicates), DLD1 (2 replicates) and SW620 (2 replicates), by employing CUT&RUN (C&R) with Low-Volume and Urea (LoV-U; Zambanini et al., 2022).
Project description:In our attempts to profile different regulators of the WNT/b-catenin transcriptional complex, CUT&RUN failed to produce consistent binding patterns of the non-DNA-binding b-catenin. We developed a modified CUT&RUN protocol, which we refer to as LoV-U (Low Volume and Urea), that enables the generation of robust and reproducible b-catenin binding profiles. CUT&RUN-LoV-U can profile all classes of chromatin regulators tested, as shown by datasets targeting the TCF/LEF transcription factors and various histone modifications. CUT&RUN-LoV-U uncovers direct WNT/β-catenin target genes in human cells, as well as in ex vivo cells isolated from developing mouse tissue.
Project description:We performed high numbers of replicates of CUT&RUN LoV-U against H3K4me3, β-catenin, and the negative control IgG in human colorectal cancer HCT116 cells over two independent rounds of experiments to discover the complete set of binding events.
Project description:Using CUT&RUN, we systematically measured the genome-wide binding profiles of key transcription factors and cofactors that track the activity of ontogenetically relevant signaling pathways in developing mouse tissues. This produced numerous genome-wide biding tracks for different tissues at two developmental stages in biological duplicate. Submitted files include raw fastq files, bigwig files from merged biological replicates, and peak sets.
Project description:We made an insulation (STITCH+30kb) allele of the MYC enhancer in human iPS cells. We integrated a transgene consisting of tetR-KRAB followed by DNA encoding the 2A peptide and the puromycin resistant gene with piggyBac transposition into the genome in the STITCH+30kb clone (STITCH/KRAB). We performed nChIP-seq for CTCF, H3K4me3, H3K27me3 and H3K9me3, in these clones in human iPS cells.
Project description:TNFα is a potent cytokine to mediate inflammatory response by activation of the master transcription factor NF-kB. Endothelial cells are important participants in inflammatory responses in animals. NF-kB is a major mediator to activate endothelial cells by inducing multiple pro-inflammatory genes in response to TNFα. The process of transcriptional activation is dependent on the context of chromatin interactions/loops. However, the chromatin conformation in response to the cytokine challenge TNFα in human aortic endothelial cells has not been described. Our approach characterized chromatin interactions from active enhancers to promoters as well as active promoters to promoters on a genome-wide scale and highlighted important enhancer candidates for target genes.
Project description:The experiment was carried out to examine the effect of Srrt knockdown on the U1 snRNP/pre-mRNA interaction pattern. A2Lox mouse embryonic stem cells were transfected with either an Srrt-specific or a non-targeting siRNA. 48 hours post transfection the cells were cross-linked using 2% formaldehyde and lysed. RNA was partially fragmented by sonication, hybridized with U1 snRNA-specific biotinilated probes and pulled down. U1-associated RNA sequences were then purified and RNA-seq libraries were generated using a NEBNext® rRNA Depletion Kit and NEBNext® Ultra8482 II Directional RNA Library Preparation kit. Paired-end sequencing was performed using a HiSeq4000 75bp platform.
Project description:Despite serving as a central experimental technique in epigenetics research, chromatin immunoprecipitation (ChIP) suffers from several serious drawbacks: it is a relative measurement untethered to any external scale that obviates fair comparison amongst experiments; it employs antibody reagents that have differing affinity and specificity for target epitopes, which are in turn variable in abundance; and it is frequently not reproducible. To address these problems, we developed internal standard calibrated ChIP (ICeChIP), a method of spiking a native chromatin sample with nucleosomes reconstituted from recombinant and semisynthetic histones on barcoded DNA prior to immunoprecipitation. ICeChIP measures local histone modification densities on a biologically meaningful scale, enabling unbiased trans-experimental comparisons and revealing a correlation between the apparent symmetry of H3K4me3 in promoter nucleosomes and gene expression. Direct in situ assessment of immunoprecipitation accommodates for a number of experimental pitfalls, and provides a critical examination of untested assumptions inherent in conventional ChIP. Examination of spiked-in semi-synthetic nucleosomes in ICeChIP-seq experiments performed for HEK293, mESC E14 and DM S2 cell line
Project description:We performed 8 C&R tests in HEK293T human cells and 8 in mouse embryonic tissues from JAX Swiss mice by using either IgG or anti-HA antibodies. To increase diversity in this test, we used both the original C&R protocol and our recently developed C&R-LoV-U version for non-DNA-binding transcriptional co-factors. The aim was to experimentally validate our generated CUT&RUN blacklists containing problematic high signal regions.