The IRE1a-XBP1 pathway promotes T helper cell differentiation by resolving secretory stress and accelerating proliferation (ChIP-seq)
ABSTRACT: The IRE1a-XBP1 pathway, a conserved adaptive response to the unfolded protein response, is indispensable for development of the secretory cells. It maintains endoplasmic reticulum homeostasis by enhancing protein folding and the secretory capacity of the cells. Here, we used a modified ChIP-seq protocol (ChIPmentation) to investigate the genome-wide binding events of the transcription factor XBP1 in differentiated mouse Th2 cells.
Project description:Dermal fibroblasts from human, rhesus macaque, mouse and rat with and without dsRNA (poly I:C) stimulation (1ug/mL for 4 hours).<br>The innate immune response - the expression programme that is initiated once a pathogen is sensed - is known to be variable among responding cells, as well as to rapidly evolve in the course of mammal evolution. To study the transcriptional divergence and cell-to-cell variability of this response, we stimulated dermal fibroblast cells from two primates (human and macaque) and two rodents (mouse and rat) with dsRNA - a mimic of viral RNA that elicits a rapid innate immune response. Subsequently, we profiled the response using bulk RNA-seq, scRNA-seq and ChIP-seq across the four species and across different time points.
Project description:The assay for transposase-accessible chromatin using sequencing (ATAC-seq) is widely used to identify regulatory regions throughout the genome. However, only a few studies have been done at the single cell level (scATAC-seq) due to technical difficulties. Here we developed a simple and robust plate-based scATAC-seq method, combining upfront bulk tagmentation with single-nuclei sorting, to investigate open chromatin regions. We applied this method on mouse splenocytes and unbiasedly revealed key regulatory regions and transcription factors that define each cell (sub)type.
Project description:We over-expressed an epigenetic regulator in a glioblastoma (GBM) primary culture from an adult patient. These GBM cells have cancer stem cell phenotypes, as they have self-renewal properties and tumor initiation potential when transplanted in immunocompromised mice. ATAC-seq was performed on cells over-expressing the epigenetic regulator and control cells expressing EGFP. ATAC-Seq on glioblastoma cells that over-express EGFP or an epigenetic regulator.
Project description:To identify conserved TNFα-induced changes in chromatin-accessibility in mammals, we performed ATAC-seq in primary vascular endothelial cells (ECs) isolated from the aortas of human (HAEC), mouse (MAEC) and cow (BAEC), before and after TNFα. We overlay our data with multi-species NF-κB binding data and identify multiple modes of NF-κB-chromatin interactions that are conserved during mammalian TNFα response. Our cross-species approach identifies conserved changes in chromatin-accessibility at NF-κB binding sites that are disease-relevant and essential during mammalian acute inflammation.
Project description:High grade serous ovarian cancers (HGSC) are deadly malignancies that relapse despite carboplatin chemotherapy. Here we show that 16 independent primary HGSCs contain a CA125 negative population enriched for carboplatin resistant cancer initiating cells. Transcriptome analysis reveals up-regulation of homologous recombination DNA repair and anti-apoptotic signals in this population. While treatment with carboplatin enriches for CA125 negative cells, co-treatment with carboplatin and birinapant eliminates these cells in HGSCs expressing high levels of the inhibitor of apoptosis protein cIAP in the CA125 negative population. Birinapant sensitizes CA125 negative cells to carboplatin by mediating degradation of cIAP causing cleavage of caspase-8 and restoration of apoptosis. This co-therapy significantly improved disease free survival in vivo compared to either therapy alone in tumor-bearing mice. These findings suggest that therapeutic strategies that target CA125 negative cells may be useful in the treatment of HGSC. mRNA profiles of CA125 positive and negative populations, generated by next generation sequencing of populations FACS isolated from 10 independent dissociated primary human high grade serous ovarian cancers, were compared.
Project description:In neuroblastoma, amplification of the oncogenic basic helix-loop-helix (bHLH) transcription factor (TF) MYCN is the defining prognosticator of high-risk disease, occurs in one-third of neuroblastoma, and drastically reduces overall survival rates1,2. As a proto-oncogene, targeted MYCN overexpression in peripheral neural crest is sufficient to initiate disease in mouse models3. In MYCN amplified neuroblastoma, elevated expression of the factor is crucial to maintain tumor stemness4,5 and is associated with increased proliferation and aberrant cell cycle progression, as these tumors lack the ability to arrest in G1 in response to irradiation6-9. MYCN down-regulation broadly reverses these oncogenic phenotypes in a variety of neuroblastoma models10-12 and recent thereapeutic strategies to indirectly target MYCN production or protein stability have reduced tumor growth in vivo13-15. These observations motivate an investigation of MYCN binding in MYCN amplified tumors as it remains fundamentally unclear how elevated levels of the factor occupy the genome and alter transcriptional programs in neuroblastoma. Here we present the first dynamic chromatin and transcriptional landscape of direct MYCN perturbation in neuroblastoma. We find that at oncogenic levels, MYCN associates with E-box (CANNTG) binding motifs in an affinity dependent manner across most active cis-regulatory promoters and enhancers. MYCN shutdown globally reduces histone acetylation and transcription, consistent with prior descriptions of MYC proteins as non-linear amplifiers of gene expression. We establish that MYCN load at the promoter and proximal enhancers predicts transcriptional responsiveness to MYCN shutdown and that MYCN enhancer binding occurs prominently at the most strongly occupied and down-regulated genes, suggesting a role for these tissue specific elements in predicating MYCN responsive “target” genes. At these invaded enhancers, we identify the lineage specific bHLH TWIST1 as a key collaborator and dependency of oncogenic MYCN. These data suggest that MYCN enhancer invasion helps shape transcriptional amplification of the neuroblastoma gene expression program to promote tumorigenesis. ATAC-Seq in SHEP21, BE2C, KELLY, NGP, and MM1S cell lines
Project description:For unbiased, whole-organism wide cell type profiling, we randomly sampled cells from dissociated Platynereis larvae. To generate the single-cell mRNA-sequencing data, P. dumerilii larvae were dissociated, followed by cell capture, cDNA synthesis and amplification on the C1 Single-Cell Auto Prep IFCs for 5-10 um or 10-17 um cells (Fluidigm). Sequencing libraries were produced using Nexera XT DNA kit (Illumina). In total, we sequenced 596 samples, of which 373 correspond to single, alive cells that passed the quality check criteria. Part of this dataset was previously published (ArrayExpress accession number E-MTAB-2865). Here, we publish additional 383 sequenced cells.