Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE84457 | GEO | 2016/07/15
SECONDARY ACCESSION(S): PRJNA329231
REPOSITORIES: GEO
Similar Datasets
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: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
| PRJNA329231 | ENA
Project description:Ascl2 acts as an R-spondin/Wnt responsive switch to control stemness in intestinal crypts [ChIP-seq]
| PRJNA329245 | ENA
Project description:Mutated tumor cells undergo changes in chromatin accessibility and gene expression, resulting in aberrant proliferation and differentiation, although how this occurs is unclear. HMGA1 chromatin regulators are abundant in stem cells and oncogenic in diverse tissues; however, their role in colon tumorigenesis is only beginning to emerge. Here, we uncover a previously unknown epigenetic program whereby HMGA1 amplifies Wnt signaling during colon tumorigenesis driven by inflammatory microbiota and/or Adenomatous polyposis coli (Apc) inactivation. Mechanistically, HMGA1 "opens" chromatin to upregulate the stem cell regulator, Ascl2, and downstream Wnt effectors, promoting stem and Paneth-like cell states while depleting differentiated enterocytes. Loss of just one Hmga1 allele within colon epithelium restrains tumorigenesis and Wnt signaling driven by mutant Apc and inflammatory microbiota. However, HMGA1 deficiency has minimal effects in colon epithelium under homeostatic conditions. In human colon cancer cells, HMGA1 directly induces ASCL2 by recruiting activating histone marks. Silencing HMGA1 disrupts oncogenic properties, whereas reexpression of ASCL2 partially rescues these phenotypes. Further, HMGA1 and ASCL2 are coexpressed and upregulated in human colorectal cancer. Together, our results establish HMGA1 as an epigenetic gatekeeper of Wnt signals and cell state under conditions of APC inactivation, illuminating HMGA1 as a potential therapeutic target in colon cancer.
| S-EPMC11785931 | biostudies-literature
Project description:BackgroundCanonical Wnt pathway signaling is necessary for maintaining the proliferative capacity of mammalian intestinal crypt base columnar stem cells (CBCs). Furthermore, dysregulation of the Wnt pathway is a major contributor to disease, including oncogenic transformation of the intestinal epithelium. Given the critical importance of this pathway, numerous tools have been used as proxy measures for Wnt pathway activity, yet the relationship between Wnt target gene expression and reporter allele activity within individual cells at the crypt base remains unclear.ResultsHere, we describe a novel Axin2-CreERT2-tdTomato allele that efficiently marks both Wnt(High) CBCs and radioresistant reserve intestinal stem cells. We analyze the molecular and functional identity of Axin2-CreERT2-tdTomato-marked cells using single cell gene expression profiling and tissue regeneration assays and find that Axin2 reporter activity does not necessarily correlate with expression of Wnt target genes and, furthermore, that Wnt target genes themselves vary in their expression patterns at the crypt base.ConclusionsWnt target genes and reporter alleles can vary greatly in their cell-type specificity, demonstrating that these proxies cannot be used interchangeably. Furthermore, Axin2-CreERT2-tdTomato is a robust marker of both active and reserve intestinal stem cells and is thus useful for understanding the intestinal stem cell compartment. Developmental Dynamics 245:822-833, 2016. © 2016 Wiley Periodicals, Inc.
| S-EPMC4946997 | biostudies-literature
Project description:N6-methyladenosine (m6A) mRNA methylation has emerged as an important player in many biological processes by regulating gene expression. However, its roles in intestinal stem cell (ISC) homeostasis remain largely unknown. Here we report that YTHDF1, an m6A reader, is highly expressed in ISCs and its expression is upregulated by Wnt signaling at the translational level. Whereas YTHDF1 is dispensable for normal intestinal development in mice, genetic ablation of Ythdf1 dramatically blocks Wnt-driven regeneration and tumorigenesis with reduced ISC stemness. Mechanistically, YTHDF1 facilitates the translation of Wnt signaling effectors including TCF7L2/TCF4, while this process is enhanced during Wnt activation to augment ?-catenin activity. Targeting YTHDF1 in ISCs of established tumors leads to tumor shrinkage and prolonged survival. Collectively, our studies unveil YTHDF1 as an amplifier of Wnt/?-catenin signaling at the translational level, which is required for the maintenance of ISCs during regeneration and tumorigenesis.
| S-SCDT-EMBOR-2019-49229-T | biostudies-other
Project description:N6-methyladenosine (m6 A) mRNA methylation has emerged as an important player in many biological processes by regulating gene expression. However, its roles in intestinal stem cell (ISC) homeostasis remain largely unknown. Here, we report that YTHDF1, an m6 A reader, is highly expressed in ISCs and its expression is upregulated by Wnt signaling at the translational level. Whereas YTHDF1 is dispensable for normal intestinal development in mice, genetic ablation of Ythdf1 dramatically blocks Wnt-driven regeneration and tumorigenesis with reduced ISC stemness. Mechanistically, YTHDF1 facilitates the translation of Wnt signaling effectors including TCF7L2/TCF4, while this process is enhanced during Wnt activation to augment β-catenin activity. Targeting YTHDF1 in ISCs of established tumors leads to tumor shrinkage and prolonged survival. Collectively, our studies unveil YTHDF1 as an amplifier of Wnt/β-catenin signaling at the translational level, which is required for the maintenance of ISCs during regeneration and tumorigenesis.
| S-EPMC7132202 | biostudies-literature