ABSTRACT: The impact of removal of Mll1 in intestinal Paneth cells expressing an constitutively active form of beta-catenin (beta-cateninGOF) was analysed in 4 pairs of sorted Paneth cells of Lgr5-CreERT2; beta-cateninGOF;Mll1+/- (control) and Lgr5-CreERT2; beta-cateninGOF;Mll1-/- (knockout) mice at 10 days after tamoxifen-induced mutagenesis. Using 75-base-pair reads, around 30 million reads per sample with comparable unique mapped reads (52-93%) were obtained. To analyze differentially expressed genes, we applied DESeq2 analysis to the RNA-seq dataset. Differentially expressed genes in beta-cateninGOF; Mll1-/- versus beta-cateninGOF; Mll1+/- Paneth cells showed both up- and downregulation of genes at a false discovery rate (FDR) of 10%. This included a global increase in the expression of goblet cell-specific genes. Downregulated genes included specific markers of Paneth cells, indicating that ablation of Mll1 in Paneth cells shifted their identity towards a mixed Paneth-goblet cell fate.
Project description:The impact of Mll1 removal on intestinal stem cells expressing an oncogenic form of beta-catenin (beta-cateninGOF) was analysed in 4 pairs of sorted intestinal stem cells of Lgr5-CreERT2; beta-cateninGOF;Mll1+/- (control) and Lgr5-CreERT2; beta-cateninGOF;Mll1-/- (knockout) at 10 days after tamoxifen-induced mutagenesis. Using 75-base-pair reads, around 30 million reads per sample with comparable unique mapped reads (73-78%) were obtained. To analyze differentially expressed genes, we applied DESeq2 analysis to the RNA-seq dataset. Differentially expressed genes in beta-cateninGOF; Mll1-/- versus beta-cateninGOF; Mll1+/- stem cells showed both up- and downregulation of genes at a false discovery rate (FDR) of 10%. This included a global increase in the expression of goblet cell-specific genes. Downregulated genes included specific markers of Paneth cells, indicating that ablation of Mll1 shifted the Paneth-like identity of beta-cateninGOF stem cells towards a goblet cell fate. The stem cell transcriptome further revealed that beta-cateninGOF; Mll1-/- stem cells exhibited a decreased expression of several transcription factors and stem cell genes.
Project description:The impact of Mll1 removal on the intestinal stem cells and its direct effect on neighbouring Paneth cells was evaluated in sorted intestinal stem and Paneth cells from Mll1FC/+; Lgr5-eGFP-CreERT2/+ (control) and Mll1FC/FC; Lgr5-eGFP-CreERT2/+ (knockout) mice, 4 and 10 days after tamoxifen-induced mutagenesis. Using 75-base-pair reads, 30 million reads per sample with comparable unique mapped reads for stem (70-77%) and Paneth (60-76%) cells were obtained. To analyze differentially expressed genes, we applied DESeq2 analysis to the RNA-seq dataset. Analysis by DAVID and GSEA at a false discovery rate (FDR) of 5% was conducted.The stem cell transcriptome revealed that Mll1 knockout stem cells exhibited a decreased expression of several transcription factors and stem cell genes. Additionally, Mll1 ablation in stem cells had an impact on Paneth cells. Downregulation of Paneth cell specific markers indicated a loss of Paneth cell identity.
Project description:Homeostasis of self-renewing small intestinal crypts results from neutral competition between Lgr5 stem cells, small cycling cells located at crypt bottoms1, 2. Lgr5 stem cells are interspersed between terminally differentiated Paneth cells, that are known to produce bactericidal products such as lysozyme and cryptdins/defensins3. Single Lgr5-expressing stem cells can be cultured to form long-lived, self-organizing crypt-villus organoids in the absence of non-epithelial niche cells4. Here, we note a close physical association of Lgr5 stem cells with Paneth cells in vivo and in vitro. CD24+ Paneth cells express EGF, TGF?, Wnt3 and the Notch-ligand Dll4, all essential signals for stem cell maintenance in culture. Co-culturing of sorted stem cells with Paneth cells dramatically improves organoid formation. This Paneth cell requirement can be substituted by a pulse of exogenous Wnt. Genetic removal of Paneth cells in vivo results in the concomitant loss of Lgr5 stem cells. In colon crypts, CD24+ cells residing between Lgr5 stem cells may represent the Paneth cell equivalents. We conclude that Lgr5 stem cells compete for essential niche signals provided by a specialized daughter cell, the Paneth cell. We used intestinal cell fractions from Lgr5-EGFP-ires-CreERT2 mice, expressing GFP under the control of the Lgr5 promoter. RNA was isolated from two FACS sorted cell populations: stem cells were sorted based on high level of GFP expression (GFPhi) and Paneth cells were sorted based on high level of CD24 expression (CD24hi) and high side-scatter (SSChi). Differentially labelled cRNA from GFPhi and CD24hi/SSChi cells from two different sorts (each combining ten individual mice) were hybridized on 4X44K Agilent Whole Mouse Genome dual colour Microarrays (G4122F) in two dye swap experiments, resulting in four individual arrays.
Project description:Paneth cells (PCs) are long-lived secretory cells that reside at the bottoms of small intestinal crypts. Besides serving as niche cells for the neighboring Lgr5-positive stem cells, PCs secrete granules containing a broad spectrum of antimicrobial proteins, including lysozymes and defensins1. Here, we have used single-cell RNA sequencing to explore PC differentiation. We found a maturation gradient from early secretory progenitors to mature PCs, capturing the full maturation path of PCs. Moreover, differential expression of a subset of defensin genes in lysozyme-high PCs, e.g. Defa20, reveals at least two distinct stages of maturation. We traced Lgr5+ stem cells from Lgr5-CreERT2 C57Bl6/J mice bred to a Rosa26LSL-YFP reporter mice and sorted YFP+ cells 5 days, 3 weeks and 8 weeks after tamoxifen injection.
Project description:To analyze global gene-expression changes caused by IRF2 loss in ISCs, ISCs were prepared from Irf2fl/fl: Lgr5-EGFP-Ires-CreERT2(Irf2fl/fl: Lgr5ki) mice or Irf2fl/fl: Ah-Cre: Lgr5-EGFP-Ires-CreERT2 (Irf2AhcKO: Lgr5ki) mice 1 month after 5 consecutive days of βNF treatment. The Gene Ontology (GO) analysis indicated that the GO terms overrepresented among the genes upregulated in ISCs of βNF treated Irf2AhcKO: Lgr5ki mice compared with those of Irf2fl/fl: Lgr5ki mice included “immune system process”, “immune response”, and “cellular response to Interferon-beta”, all from the GOTERM_Biological Processes (BP) category. Because these GO_term inculded many IFN-inducibl genes, IFN signaling augumented in Irf2 deleted ISCs.
Project description:The molecular mechanisms controlling stem cell renewal and lineage commitment are still poorly understood due to lack of reliable markers. In the adult small intestine, an example of high rate self-renewing tissue, four different epithelial cell lineages (enterocytes, Goblet, enteroendocrine and Paneth cells) are generated from a pool of stem cells localised at the bottom of the crypts of Lieberkühn. Recently, the orphan Leucine-rich repeat G protein-coupled receptor 5 (GPR49), a target of Wnt signalling, has been proposed as a marker for such cells. We investigated the role of LGR5 during intestinal development by using LGR5 null/LacZ-NeoR knock-in mice. We show that LGR5 deficiency leads to premature Paneth cell differentiation. X-gal staining on E18.5 intestine revealed that LGR5 expression is restricted to a few cells clustered within the intervillus region known to contain progenitor cells. In LGR5-null mice, expression from the LGR5 promoter was found upregulated, suggesting a loss of negative feedback control. However, neither epithelial cell proliferation nor cell migration appeared significantly impaired by LGR5 deficiency. Finally, transcriptional profiling of ileal mutant mice suggests that LGR5 plays a role in regulating the Wnt and Notch signalling pathways controlling progenitor renewal and differentiation.
Project description:Homeostasis of self-renewing small intestinal crypts results from neutral competition between Lgr5 stem cells, small cycling cells located at crypt bottoms1, 2. Lgr5 stem cells are interspersed between terminally differentiated Paneth cells, that are known to produce bactericidal products such as lysozyme and cryptdins/defensins3. Single Lgr5-expressing stem cells can be cultured to form long-lived, self-organizing crypt-villus organoids in the absence of non-epithelial niche cells4. Here, we note a close physical association of Lgr5 stem cells with Paneth cells in vivo and in vitro. CD24+ Paneth cells express EGF, TGFα, Wnt3 and the Notch-ligand Dll4, all essential signals for stem cell maintenance in culture. Co-culturing of sorted stem cells with Paneth cells dramatically improves organoid formation. This Paneth cell requirement can be substituted by a pulse of exogenous Wnt. Genetic removal of Paneth cells in vivo results in the concomitant loss of Lgr5 stem cells. In colon crypts, CD24+ cells residing between Lgr5 stem cells may represent the Paneth cell equivalents. We conclude that Lgr5 stem cells compete for essential niche signals provided by a specialized daughter cell, the Paneth cell.
Project description:Upon tamoxifen induced recombination, Villin-CreERT2+ Lsd1fl/fl (icKO) mice develop an immature intestinal epithelium characterized by an incomplete differentiation of enterocytes and secretory lineages, reduced number of goblet cells and a complete loss of Paneth cells. The main goal of this experiment was to test whether maturation of intestinal epithelium affects microbiota establishment and development. In addition, this loss of differentiated cell types after Lsd1 recombination is gradual and dependent on renewal times of each specific cell type (i.e. enterocytes take less than a week to be fully replenished while Paneth cells cycle around every 4 weeks). Hence by collecting stool from the same mouse at different time points after tamoxifen induced recombination a relationship between loss of particular cell types and changes in bacterial populations can be established. In addition, we wanted to test whether maturation of intestinal epithelium affects microbiota establishment and development
Project description:BACKGROUND & AIMS: Stems cells within the intestinal epithelium generate daughter cells which undergo lineage commitment and maturation through the concerted action of the Wnt and Notch signalling cascades. Both pathways, in turn, regulate transcription factor networks which further define differentiation towards either enterocytes or one of three secretory cell lineages (Paneth, goblet or enteroendocrine cells). In this manuscript, we identified the Ets domain transcription factor, Spdef, as a novel lineage maker of goblet and Paneth cells. METHODS: To address the function of Spdef in vivo, we inactivated the Spdef gene and analysed the intestinal phenotype using a range of histological techniques and DNA microarray profiling. RESULTS: In accordance with the expression data we found that loss of Spdef severely impaired the maturation of goblet and Paneth cells and conversely lead to an accumulation of immature secretory progenitors. Moreover, we provide evidence suggesting that Spdef positively and negatively regulates a specific subset of goblet and Paneth cell genes including Cryptdins, Mmp7, Ang4, Kallikreins, and Muc2. CONCLUSION: We propose a model whereby Spdef acts downstream of Math1 to promote terminal differentiation of a secretory progenitor pool towards Paneth and goblet cells. Keywords: expression profiling
Project description:Enterocytes and four classic secretory cell types derive from intestinal epithelial stem cells. Based on morphology, location, and canonical markers, goblet and Paneth cells are considered distinct secretory types. Here, we report high overlap in their transcripts and sites of accessible chromatin, in marked contrast to those of their enteroendocrine or tuft cell siblings. Mouse and human goblet and Paneth cells express extraordinary fractions of few antimicrobial genes, which reflect specific responses to local niches. Wnt signaling retains some ATOH1+ secretory cells in crypt bottoms, where absence of BMP signaling potently induces Paneth features. Cells that migrate away from crypt bottoms encounter BMPs and thereby acquire goblet properties. These phenotypes and underlying accessible cis-elements interconvert in post-mitotic cells. Thus, goblet and Paneth properties represent alternative phenotypic manifestations of a common signal-responsive terminal cell type. These findings reveal exquisite niche-dependent cell plasticity and cis-regulatory dynamics in likely response to antimicrobial needs