Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts
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PROVIDER: PRJNA329231 | ENA |
REPOSITORIES: ENA
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Project description:Wnt signals control three functions of intestinal crypts: maintenance of Lgr5 stem cells, proliferation of transit-amplifying daughters and formation of Paneth cells. Here, we study how the Wnt effector β-catenin/Tcf4 cooperates with the Wnt-activated transcription factor Ascl2 to control a stem cell transcription program. DNA elements that are co-occupied and synergistically regulated by Ascl2 and Tcf4 specifically map to stem cell genes. In vitro, Tcf4-/- mini-guts are rescued by Ascl2 expression, while Ascl2-/- organoids are rescued by Wnt signaling. A direct auto-activatory loop leads to an on/off expression pattern of Ascl2 with a threshold that depends on the previous state. Wnt/R-spondin1 activates this loop. This mechanism interprets Wnt levels in crypts and translates this continuous signal into a discrete Ascl2 âonâ or âoffâ decision. In turn Ascl2, together with β-catenin/Tcf, activates stem cell genes. Thus, Ascl2 forms a transcriptional 'stemness switch' that is both Wnt-responsive and Wnt-dependent Examination of Tcf4, B-catenin and Ascl2 DNA occupancy in murine intestinal organoids and human colorectal cancer cell lines *** Original raw files unavailable due to loss during backup ***
2016-07-15 | E-GEOD-84456 | biostudies-arrayexpress
Project description:Wnt signals control three functions of intestinal crypts: maintenance of Lgr5 stem cells, proliferation of transit-amplifying daughters and formation of Paneth cells. Here, we study how the Wnt effector β-catenin/Tcf4 cooperates with the Wnt-activated transcription factor Ascl2 to control a stem cell transcription program. DNA elements that are co-occupied and synergistically regulated by Ascl2 and Tcf4 specifically map to stem cell genes. In vitro, Tcf4-/- mini-guts are rescued by Ascl2 expression, while Ascl2-/- organoids are rescued by Wnt signaling. A direct auto-activatory loop leads to an on/off expression pattern of Ascl2 with a threshold that depends on the previous state. Wnt/R-spondin1 activates this loop. This mechanism interprets Wnt levels in crypts and translates this continuous signal into a discrete Ascl2 “on” or “off” decision. In turn Ascl2, together with β-catenin/Tcf, activates stem cell genes. Thus, Ascl2 forms a transcriptional 'stemness switch' that is both Wnt-responsive and Wnt-dependent.
2014-12-31 | GSE57053 | GEO
Project description:Wnt signals control three functions of intestinal crypts: maintenance of Lgr5 stem cells, proliferation of transit-amplifying daughters and formation of Paneth cells. Here, we study how the Wnt effector β-catenin/Tcf4 cooperates with the Wnt-activated transcription factor Ascl2 to control a stem cell transcription program. DNA elements that are co-occupied and synergistically regulated by Ascl2 and Tcf4 specifically map to stem cell genes. In vitro, Tcf4-/- mini-guts are rescued by Ascl2 expression, while Ascl2-/- organoids are rescued by Wnt signaling. A direct auto-activatory loop leads to an on/off expression pattern of Ascl2 with a threshold that depends on the previous state. Wnt/R-spondin1 activates this loop. This mechanism interprets Wnt levels in crypts and translates this continuous signal into a discrete Ascl2 “on” or “off” decision. In turn Ascl2, together with β-catenin/Tcf, activates stem cell genes. Thus, Ascl2 forms a transcriptional 'stemness switch' that is both Wnt-responsive and Wnt-dependent
2016-07-15 | GSE84456 | GEO
Project description:Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts [ChIP-seq]
| PRJNA329245 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2016-07-15 | E-GEOD-84457 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below.
2016-07-15 | GSE84457 | GEO
Project description:Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts [array]
| PRJNA245327 | ENA
Project description:The small intestinal epithelium is the most rapidly self-renewing tissue of mammals. Proliferative cells are confined to crypts, while differentiated cell types predominantly occupy the villi. We recently demonstrated the existence of a long-lived pool of cycling stem cells defined by Lgr5 expression and intermingled with post-mitotic Paneth cells at crypt bottoms. We have now determined a gene signature for these so called Crypt Base Columnar (CBC) cells. One of the genes within this stem cell signature is the Wnt target Ascl2. Transgenic expression of the Ascl2 transcription factor throughout the intestinal epithelium induces crypt hyperplasia and de novo crypt formation on villi. Induced deletion of the Ascl2 gene in adult small intestine leads to disappearance of the CBC stem cells within days. The combined results from these gain- and loss-of-function experiments imply that Ascl2 controls intestinal stem cell fate. Experiment Overall Design: For the stem cell signature we used cell fractions of intestines from Lgr5-EGFP-ires-CreERT2 mice, expressing GFP under the control of the Lgr5 promoter. RNA was isolated from two FACS sorted cell populations, one expressing GFP at high levels (GFPhi) and the other expressing GFP at low levels (GFPlo). For the analysis of Ascl2 target genes RNA was isolated from intestinal epithelial cells of Ah-Cre/Ascl2floxed/floxed animals and Ah-Cre/Ascl2floxed/wt control animals 3 and 5 days post induction. Differentially labelled cRNA from GFPhi and GFPlo cells from two different sorts (each combining three different mice) were hybridised on 4X44K Agilent Whole Mouse Genome dual colour Microarrays (G4122F) in two dye swap experiments, resulting in four individual arrays. For the Ascl2 target gene analysis we analyzed the 3 and 5 days PI experiments in two dye swap experiments, resulting in four individual arrays.
2009-03-25 | E-GEOD-14201 | biostudies-arrayexpress
Project description:The small intestinal epithelium is the most rapidly self-renewing tissue of mammals. Proliferative cells are confined to crypts, while differentiated cell types predominantly occupy the villi. We recently demonstrated the existence of a long-lived pool of cycling stem cells defined by Lgr5 expression and intermingled with post-mitotic Paneth cells at crypt bottoms. We have now determined a gene signature for these so called Crypt Base Columnar (CBC) cells. One of the genes within this stem cell signature is the Wnt target Ascl2. Transgenic expression of the Ascl2 transcription factor throughout the intestinal epithelium induces crypt hyperplasia and de novo crypt formation on villi. Induced deletion of the Ascl2 gene in adult small intestine leads to disappearance of the CBC stem cells within days. The combined results from these gain- and loss-of-function experiments imply that Ascl2 controls intestinal stem cell fate. Keywords: expression profiling
2009-03-13 | GSE14201 | GEO
Project description:Invasive trophoblast cells are critical to spiral artery remodeling in hemochorial placentation. Insufficient trophoblast invasion and vascular remodeling can lead to pregnancy disorders including preeclampsia, preterm birth, and intrauterine growth restriction. Previous studies in the mouse identified achaete-scute homolog 2 (ASCL2) as essential to extraembryonic development. We hypothesized that ASCL2 is a critical and conserved regulator of invasive trophoblast lineage development. In contrast to the mouse, the rat possesses deep intrauterine trophoblast cell invasion and spiral artery remodeling similar to human placentation. In this report, we investigated invasive/extravillous trophoblast (EVT) cell differentiation using human trophoblast stem (TS) cells and a loss-of-function mutant Ascl2 rat model. ASCL2 transcripts are expressed in the EVT column and junctional zone, which represent tissue sources of invasive trophoblast progenitor cells within human and rat placentation sites, respectively. Differentiation of human TS cells into EVT cells resulted in significant upregulation of ASCL2 and several other transcripts indicative of EVT cell differentiation. Disruption of ASCL2 impaired EVT cell differentiation as indicated by cell morphology and transcript profiles. RNA sequencing analysis of ASCL2-deficient trophoblast cells identified both downregulation of EVT cell-associated transcripts and upregulation of syncytiotrophoblast-associated transcripts, indicative of dual activating and repressing functions. ASCL2 deficiency in the rat impacted placental morphogenesis resulting in junctional zone dysgenesis and failed intrauterine trophoblast cell invasion. ASCL2 acts as a critical and conserved regulator of invasive trophoblast cell lineage development and a species-specific modulator of the syncytiotrophoblast lineage.
2021-03-01 | GSE154350 | GEO