BART-Seq: cost-effective massively parallelized targeted sequencing for genomics, transcriptomics, and single cell analysis [Differentiation]
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ABSTRACT: We describe a novel workflow named Barcode Assembly foR Targeted Sequencing, which is a highly sensitive, quantitative, and inexpensive technique for targeted sequencing of transcript cohorts (rBART-Seq) or genomic regions (gBART-Seq) from thousands of bulk samples or single cells in parallel. Multiplexing is based on a simple method that produces extensive matrices of diverse DNA barcodes attached to invariant primer sets, for generating amplicons with dual indices. Here, we used the rBART-Seq to analyze cell subpopulations that emerge during 72 hours of Wnt/β-catenin pathway activation of H9 hESCs using recombinant Wnt protein (rWnt3a), a small molecule inhibitor of GSK-3 (CHIR99021), or Dox-inducible constitutively active β-catenin (ΔN90).
Project description:We describe a novel workflow named Barcode Assembly foR Targeted Sequencing, which is a highly sensitive, quantitative, and inexpensive technique for targeted sequencing of transcript cohorts (rBART-Seq) or genomic regions (gBART-Seq) from thousands of bulk samples or single cells in parallel. Multiplexing is based on a simple method that produces extensive matrices of diverse DNA barcodes attached to invariant primer sets, for generating amplicons with dual indices. Here, we used the gBART-Seq for genetic screening of breast cancer patients and identified BRCA mutations with very high precision.
Project description:We describe a novel workflow named Barcode Assembly foR Targeted Sequencing, which is a highly sensitive, quantitative, and inexpensive technique for targeted sequencing of transcript cohorts (rBART-Seq) or genomic regions (gBART-Seq) from thousands of bulk samples or single cells in parallel. Multiplexing is based on a simple method that produces extensive matrices of diverse DNA barcodes attached to invariant primer sets, for generating amplicons with dual indices. Here, we used the rBART-Seq for RNA quantification, and for the analysis of developmental states of thousands of single human pluripotent stem cells maintained in different media (mTeSR™1, KSR-bFGF, and E8).
Project description:The objective of this study was to investigate the roles of GSK3 inhibitor CHIR99021 and MEK inhibitor PD0325901 on 2i-adapted mouse embryonic stem cells (ESCs) in serum-free conditions.Canonical Wnt signaling supports the pluripotency of mouse ESCs but also promotes differentiation of early mammalian cell lineages. To explain these paradoxical observations, we explored the gene regulatory networks at play. Canonical Wnt signaling is intertwined with the pluripotency network comprising Nanog, Oct4, and Sox2 in mouse ESCs. In defined media supporting the derivation and propagation of mouse ESCs, Tcf3 and β-catenin interact with Oct4; Tcf3 binds to Sox motif within Oct-Sox composite motifs that are also bound by Oct4-Sox2 complexes. Further, canonical Wnt signaling up-regulates the activity of the Pou5f1 distal enhancer via the Sox motif in mouse ESCs. When viewed in the context of published studies on Tcf3 and β-catenin mutants, our findings suggest that Tcf3 counters pluripotency by competition with Sox2 at these sites, and Tcf3 inhibition is blocked by β-catenin entry into this complex. Wnt pathway stimulation also triggers β-catenin association at regulatory elements with classic Lef/Tcf motifs associated with differentiation programs. The failure to activate these targets in the presence of a MEK/ERK inhibitor essential for mouse ESC culture suggests that MEK/ERK signaling and canonical Wnt signaling combine to mouse promote ESC differentiation. Triplicates of mouse embryonic stem cells cultured under the following conditions: 1) CHIR99021+PD0325901+LIF; 2) CHIR99021+PD0325901; 3) CHIR99021; 4) PD0325901; 5) DMSO
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. Here, we combined RNA sequencing with CUT&RUN-LoV-U against β-catenin to assess the correlation between β-catenin recruitment to target loci and its effect on target gene expression. To this end, we performed a bulk RNA sequencing analysis on human embryonic stem cells (hESCs) treated with the the GSK3 inhibitor/Wnt activator CHIR99021 (10 mM) for 3 days, and compared them to untreated hESCs. We then correlated the observed gene expression changes with β-catenin binding events identified from a separate experiment (see “Related Accession Number”). We observed that β-catenin binding is associated with both activation and repression of cell-specific gene expression programs, underscoring how Wnt/b-catenin drives complex cell behaviors.
Project description:The aim of this study was to unravel the effects of an initial WNT/β-catenin pulse on the in vitro differentiation of human iPSCs towards mesodermal progenitors and subsequent specification of chondrocytes. Therefore, mesodermal progenitors were generated from hiPSCs according to standard protocol (ctrl) or treated with 5 µM WNT/β-catenin agoinst CHIR99021 for 24h. To understand the long-term effects of short-initial WNT pulse on mesodermal differentiation, the global gene expression profile of day 14 mesodermal progenitors was compared.
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:Branching morphogenesis in lung development is regulate by growth factor signaling. Wnt signaling is one of the important singnaling pathway that is required for progenitor maintainance. In the presence of CHIR99021, an agonist for the beta-catenin pathway of Wnt signaling, specific group of genes are upregulated in cultured lung epithelium.
Project description:Branching morphogenesis in lung development is regulate by growth factor signaling. Wnt signaling is one of the important singnaling pathway that is required for progenitor maintainance. In the presence of CHIR99021, an agonist for the beta-catenin pathway of Wnt signaling, specific group of genes are upregulated in cultured lung epithelium. RNAs were extracted from cultured epithelium and cDNAs were hybridized to Affymetrix microarrays.
Project description:Here we analysed the transcriptomic response of human embryonic stem cell line H9 to sustained activation of the canonical Wnt pathway by eiother treating cells with CHIR99021 or recombinant Wnt3a or inducing the overexpression of constitutively active beta-catenin mutant
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. Among these, one regards how the Wnt/β-catenin cascade modulates the chromatin behavior: to date, there exists no comprehensive genome-wide annotation of changing chromatin patterns upon Wnt pathway activation. This is important, as shifts in chromatin patterns might underlie how different cells promote diverging gene expression programs in response to Wnt. To address this question, we characterized how Wnt/β-catenin signaling shapes the genome-wide chromatin accessibility landscape in two human cell types, human embryonic kidney cells 293T (HEK293T) and human embryonic stem cells (hESCs), over time. To this end, we treated HEK293T and hESCs with the GSK3 inhibitor/Wnt activator CHIR99021 (10 mM) for 3 days and assessed chromatin accessibility via ATAC-sequencing 4 hours, 24 hours and 3 days after the onset of the stimulation. We found that hESCs respond to Wnt/β-catenin activation by progressively shaping their chromatin accessibility profile in a manner that is consistent with their gradual acquisition of a mesodermal identity: differentiation genes loci open over time, while pluripotency ones close. We refer to this genomic response as plastic. On the other hand, HEK293T, which are known to be highly responsive to Wnt activation, appear more resistant to a long-term Wnt/β-catenin-driven change in cell identity. In this context, the chromatin displays a temporary opening of relevant regions at 4 hours after stimulation, followed by a re-establishment of its pre-stimulation state: we define this transient response as elastic.