Project description:We compared gene expression profile of jejunum crypt samples of Sox9 deficient mice and wild type control mice in order to identify the genes that are regulated by SOX9 in the small intestinal crypt epithelial cells. The intestinal epithelial cells were collected from crypts of jejunum of three 3-mo-old Sox9 mutant mice and three littermate controls.
Project description:Aim: The mammalian gut is the largest endocrine organ. Dozens of hormones secreted by enteroendocrine cells regulate a variety of physiological functions of the gut but also of the pancreas and brain. Here, we examined the role of the helix-loop-helix transcription factor ID2 during the differentiation of intestinal stem cells along the enteroendocrine lineage. Methods: To assess the functions of ID2 in the adult mouse small intestine, we used single-cell RNA sequencing, genetically modified mice, and organoid assays. Results: We found that in the adult intestinal epithelium Id2 is predominantly expressed in enterochromaffin and peptidergic enteroendocrine cells. Consistently, the loss of Id2 leads to the reduction of Chromogranin A-positive enteroendocrine cells. In contrast, the numbers of tuft cells are increased in Id2 mutant small intestine. Moreover, ablation of Id2 elevates the numbers of Serotonin+ enterochromaffin cells and Ghrelin+ X-cells in the posterior part of the small intestine. Finally, Id2 acts downstream of BMP signalling during the differentiation of Glucagon Like Peptide-1+ L-cells and Cholecystokinin+ I-cells towards Neurotensin+PYY+ N-cells. Conclusion: Id2 plays an important role in cell fate decisions in the adult small intestine. Firstly, ID2 suppresses the differentiation of secretory intestinal epithelial progenitors towards tuft cell lineage and thus controls host immune response on commensal and parasitic microbiota. Next, ID2 is essential for establishing a differentiation gradient for enterochromaffin and X-cells along the anterior-posterior axis of the gut. Finally, ID2 is necessary for the differentiation of N-cells thus ensuring a differentiation gradient along the crypt-villi axis.
Project description:Mice lacking 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) in intestinal villus and crypt epithelial cells were generated using a Villin-Cre transgene. Label free proteome profiling was measure for Wild type and KO mouse.
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:Expression profiles obtained from the villus and crypt layers of murine large intestine can elucidate the process of differentiation undergone by epithelial cells as they migrate from the undifferentiated bottom of the crypt to the villus tip before being shed into the intestinal lumen. This series includes profiles from wild type mice, as well as mice harboring mutations in genes (APC and p21) which play key roles in the differentiation process. We used microarrays to characterize gene expression profiles at the base of the crypt and at the villus tip of the lumenal layer of the large intestine in order to better understand the process of differentiation and eventual shedding undergone by cells of the large intestinal epithelium.
Project description:Expression profiles obtained from the villus and crypt layers of murine large intestine can elucidate the process of differentiation undergone by epithelial cells as they migrate from the undifferentiated bottom of the crypt to the villus tip before being shed into the intestinal lumen. This series includes profiles from wild type mice, as well as mice harboring mutations in genes (APC and p21) which play key roles in the differentiation process. We used microarrays to characterize gene expression profiles at the base of the crypt and at the villus tip of the lumenal layer of the large intestine in order to better understand the process of differentiation and eventual shedding undergone by cells of the large intestinal epithelium. Four wild type, four APC1638+/- and four p21-/- mice were sacrified and the large intestines dissected out. Cells from the villus tip and from the bottom of the crypt were isolated from the lumenal face of the each large intestine using the Weiser method of sequential elution. RNA was extracted from each eluted sample and used to hybridize to Affymetrix 3' expression arrays.
Project description:The genomic landscape of colorectal cancer (CRC) is shaped by inactivating mutations in tumour suppressors such as APC, and oncogenic mutations such as mutant KRAS. Here we used genetically engineered mouse models (GEMMs), and multimodal mass spectrometry-based metabolomics to study the impact of common genetic drivers of CRC on the metabolic landscape of the intestine. We show that untargeted metabolic profiling can be applied to stratify intestinal tissues according to underlying genetic alterations, and use mass spectrometry imaging (MSI) to identify tumour, stromal and normal adjacent tissues. By identifying ions that drive variation between normal and transformed tissues, we found dysregulation of the methionine cycle to be a hallmark of APC-deficient CRC. Loss of Apc in the murine intestine was found sufficient to drive expression of one of its enzymes, adenosylhomocysteinase (AHCY), which was also found to be transcriptionally upregulated in human CRC. Targeting of AHCY function impaired growth of APC-deficient organoids in vitro, and prevented the characteristic hyperproliferative/crypt progenitor phenotype driven by acute deletion of Apc in vivo, even in the context of mutant Kras. Finally, pharmacological inhibition of AHCY reduced intestinal tumour burden in ApcMin/+ mice indicating its potential as a metabolic drug target in CRC.