Project description:A detailed understanding of intestinal stem cell (ISC) self-renewal and differentiation is required for better treatment options for a variety of chronic intestinal diseases, however, current models of ISC lineage hierarchy and segregation are still under debate. Here we report the identification of Lgr5+ ISCs that express Flattop (Fltp), a Wnt/planar cell polarity (PCP) reporter and effector gene. Functional analysis and lineage tracing revealed that Wnt/PCP-activated Fltp+ ISCs are primed towards either the enteroendocrine or Paneth cell lineage in vivo, while retaining self-renewal and multi-lineage capacity in vitro. Surprisingly, canonical Wnt/beta-catenin- and non-canonical Wnt/PCP-activated Lgr5+ ISCs are indistinguishable by the expression of stem-cell signature or secretory lineage-specifying genes, suggesting that lineage priming and cell-cycle exit is triggered at the post-transcriptional level by polarity cues and a switch of canonical to non-canonical Wnt signalling. Pseudotemporal ordering of targeted single-cell gene expression data allowed us to delineate the ISC differentiation path into enteroendocrine and Paneth cells. Strikingly, both lineages are directly recruited from ISCs via unipotent transition states, excluding the existence of formerly predicted bi- or multipotent secretory progenitors. Transitory cells that mature into Paneth cells are defined by label-retention and co-expression of stem cell and secretory lineage genes, indicating that these cells are the previously described Lgr5+ label-retaining cells (LRCs). Taken together, we identified the Wnt/PCP pathway as a new niche signal and polarity cue regulating stem cell fate. Active Wnt/PCP signalling represents one of the earliest events in ISC lineage priming towards the Paneth and enteroendocrine cell fate, preceding lateral inhibition and expression of secretory lineage-specifying genes. Thus, our findings provide a better understanding of the niche signals and redefine the mechanisms underlying ISC lineage hierarchy and segregation. Here we establish the Wnt/Planar cell polarity (PCP) gene Flattop (Fltp) as a unique marker for intestinal LRCs and their distinct secretory fate. We show that Fltp+ cells are characterized by a combined stem cell and secretory gene signature. A subset of Fltp+ cells is classified by label-retention and predominantly locates at position +4, indicative of quiescent stem cells. Strikingly, Fltp+ LRCs are specified by Wnt/PCP signaling in contrast to actively cycling stem cells that rely on the canonical Wnt/β-catenin pathway. In mice with disturbed Wnt/PCP signaling, the differentiation of enteroendocrine cells from LRCs is impaired. These findings establish Fltp as a novel marker for intestinal LRCs and implicate Wnt/PCP signaling in cell-cycle exit and commitment of ISCs to the secretory lineage. Taken together, we not only provide a marker to study LRCs in homeostatic and diseased conditions, but also identify the Wnt/PCP signaling pathway as a therapeutic target for colorectal cancer and metabolic disease.
Project description:We performed 7 single-cell RNAseq experiments to identify progenitor cell populations in the small intestine. To also capture rare intestinal cell populations such as stem cells and secretory cells we not only analyzed crypt cells from wildtype mice but also used two reporter mouse lines: i) the FltpZV/+ mouse line of which we mixed live crypt cells with Fltp Venus reporter (FVR) positive cells at different ratios and ii) Foxa2-Venus fusion (FVF) reporter mice. The FVF-enriched samples are part of another manuscript (link to GEO# will be provided). Using this FACS-based enrichment strategy, we could identify a Paneth cell-primed ISC population and potential progenitor populations for all intestinal lineages. To assess the role of Wnt/PCP signaling for enteroendocrine and Paneth cell differentiation, we performed 4 single-cell RNAseq experiments from crypt cells of Celsr1crsh/+; FltpZV/ZV compound mutant mice. When comparing control and mutant cells we found specific transcriptional alterations in the Paneth cell lineage.
Project description:Paneth cells are targets of allo-reactive T cells during acute graft-versus-host disease (GVHD). GVHD-related loss of Paneth cells is connected to intestinal dysbiosis and a decline of antimicrobial peptides. Glucagon-like-peptide-2 (GLP-2) is an enteroendocrine tissue hormone, produced by the intestinal L-cells, that leads to expansion of Paneth cells. Microarray-based analysis of the intestinal tract revealed upregulation of a host-defense gene signature, increased Reg3-γ and Defensin-α-4 in the teduglutide treated group compared to the vehicle treated group. these results indicate that treatment of GVHD mice the GLP-2 analogue, teduglutide, restores intestinal homeostasis with increased Paneth cells and antimicrobial peptides
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:We identify arachidonic acid (AA), as a direct proliferation promoter of intestinal epithelial cells, facilitating small intestinal regeneration. In the transcriptomes, it shows that AA treatment upregulated proliferation-related genes including Wnt signaling target genes, while downregulated differentiation-related genes including enterocyte, goblet cell, Paneth cell, enteroendocrine cell, and tuft cell markers. Additionally, AA could also upregulate stem cell-associated genes which have been highly expressed three days after 12Gy IR injury (e.g. Clu, Lamc2, Anxa1, Areg, and Ly6d). The study shows that AA treatment can be considered a potential therapy for irradiation injury repair and tissue regeneration.
Project description:Purpose: Characterize functional alterations in stem cells and paneth cells obtained from young and aged mice, focusing on age-based impairment of intestinal regeneration due to a decline in canonical Wnt signaling. Methods: mRNA profiles of young and aged stem and paneth cells were generated in triplicate (with one additional young paneth sample) using the Illumina HiSeq 2500. Reads that passed quality filters were aligned to the mm10 mouse genome with annotations provided by UCSC. Results: Approximately 10 millions reads were aligned per sample, corresponding to 36186 transcripts -- of these, 19574 exhibited reasonable expression. The effect of age was tested wtihin paneth and stem cells, using unpaired t-tests with a p-value cutoff of 0.05 and fold change cutoff of 1.5. Within paneth cells, 1025 genes were significant; within stem cells, 750 genes exhibited differential regulation. Among the downregulated genes in paneth and stem cells, we observed significant enrichment of canonical Wnt signaling genes. Conclusion: Age-related downregulation of canonical Wnt signaling is involved in the impairment of intestinal regulation upon aging.
Project description:It has long been appreciated that striped pair-rule transcription factor expression is necessary for convergent extension in the early Drosophila embryo, although the mechanisms that link these transcriptional regulators to planar polarity in this tissue have long been elusive. The goal of this study was to determine the transcriptional tragets of the pair-rule transcription factors Eve and Runt in Drosophila blastoderm embryos. We compared the transcriptional profiles of late blastoderm embryos injected with either water or dsRNAs against both eve and runt to identify differentially expressed genes that may directly contribute to the establishment of planar polarity during Drosophila convergent extension. Comparing the mRNA profiles from late blastoderm Drosophila embryos injected with either water (Water) or eve+runt dsRNAs (Eve), in triplicate, using Illumina HiSeq.
Project description:Paneth cells are antimicrobial peptide-secreting cells located at the base of the crypts of the small intestine. The proteome of Paneth cells is not well defined because of their co-existence with stem cells making it difficult to culture Panth cells alone in vitro. Using a simplied toluidine blue O method for staining mouse intestinal tissue, laser capture microdissection (LCM) to isolate cells from the crypt region and surfactant assisted one pot protein digestion, we identified more than 1,300 proteins from crypts equivalent to 18,000 cells. Compared with the proteomes of villi and smooth muscle regions, the crypt proteome is highly enriched in defensins, lysozymes and other antimicrobial peptides that are characteristic of Paneth cells. The sensitivity of the LCM-based proteomics approach was also assessed using a smaller number of cell equivalent tissues, a comparable proteomic coverage can be achieved with 3,600 cells. This work is the first proteomics study of intestinal tissue enriched with Paneth cells. The simplied workflow enables profiling of Paneth cell associated pathological changes at the proteome level directly from frozen intestinal tissue. It may also be useful for proteomics studies of other spatially resolved cell types from other tissues.