Project description:Crypts were isolated from either control or YY1f/f; Vil-Cre-ERT2 mice treated with tamoxifen for 4 days to induce knockout Jejunal crypt epithelia were isolated and processed for microarray
Project description:The intestinal stem cell fuels the highest rate of tissue turnover in the body and has been implicated in intestinal disease and cancer; understanding the regulatory mechanisms controlling intestinal stem cell physiology is of great importance. Here, we provide evidence that the transcription factor YY1 is essential for intestinal stem cell renewal. We observe that YY1 loss skews normal homeostatic cell turnover, with an increase in proliferating crypt cells and a decrease in their differentiated villous progeny. Increased crypt cell numbers come at the expense of Lgr5(+) stem cells. On YY1 deletion, Lgr5(+) cells accelerate their commitment to the differentiated population, exhibit increased levels of apoptosis, and fail to maintain stem cell renewal. Loss of Yy1 in the intestine is ultimately fatal. Mechanistically, YY1 seems to play a role in stem cell energy metabolism, with mitochondrial complex I genes bound directly by YY1 and their transcript levels decreasing on YY1 loss. These unappreciated YY1 functions broaden our understanding of metabolic regulation in intestinal stem cell homeostasis.
Project description:We mesured YY1 binding in isolated mouse crypt epihtelium using ChIP-seq Jejunal crypt epithelia were isolated and processed for ChIP using YY1 antibody Santa Cruz, SC-1703, lot E0511
Project description:Ror gamma t-deficient mice lack group 3 Innate Lymphoid Cells (ILC3s) and as a result have increased tissue damage and diminished tissue repair in response to insult. To identify repair programs associated with ILC3 presence the transcriptomes of small intestinal stem cells exposed to damage in the presence or absence of ILC3 were compared. Small intestinal damage was induced in Ror gamma t-deficient Lgr5 reporter mice and littermate controls. Small intestinal epithelial stem cells were purified at days 1 and 4 after damage and subjected to RNA sequencing.
Project description:Goal: Since disease susceptibility of the intestine exhibits an anatomical bias, we propose that the chromatin landscape, especially the site-specific epigenetic differences in histone modification patterns throughout the longitudinal axis, contributes to a differential response to chemoprotective agents. Method: We assessed the chromatin structure associated with gene expression profiles in the rat proximal and distal colon by globally correlating chromatin immunoprecipitation next-generation sequencing analysis (ChIP-Seq) with mRNA transcription (RNA-Seq) data. Crypts were isolated from the proximal and distal colonic regions from rats maintained on a semi-purified diet, and mRNA gene expression profiles were generated using RNA-Seq. The remaining isolated crypts were paraformaldehyde-crosslinked and chromatin immunoprecipitated using antibodies against H3K4me3, H3K9me3, and RNA Polymerase II. Results/Conclusion: Globally, RNA-Seq results indicated that 9,866 genes were actively expressed, of which 540 genes were differentially expressed between the proximal and distal colon. With regard to differentially expressed genes, a high correlation was observed between H3K4me3-Seq and RNA-Seq data, with 96% of the canonical pathways being similarly affected in the H3K4me3-Seq and RNA-Seq data sets. Gene ontology analysis indicated that colonic crypt location significantly impacted both chromatin and transcriptional regulation of genes involved in cell transformation, lipid metabolism, lymphatic development and immune cell trafficking. Gene function analysis indicated that the PI3-Kinase signaling pathway was regulated in a site-specific manner, e.g., pathway proto-oncogenes, c-Jun, c-Fos and ATF, were up-regulated in the distal colon. Middle and long non-coding RNAs (lncRNAs) were also detected in the colon, including select lncRNAs formerly only detected in the rat nervous system. In summary, distinct combinatorial patterns of histone modifications exist in the proximal versus distal colon. These site-specific differences may explain the differential effects of chemoprotective agents on cell transformation in the ascending (proximal) and descending (distal) colon. Examination of mRNA profiles and 2 different histone modifications (H3K4me3 and H3K9me3) in 2 tissue types (proximal and distal colon).
Project description:These data include the genome wide occupancy of histone modifications and transcription factors by ChIP sequencing in mouse crypt cells and in mouse ISCs. Immuno-precipitation of formaldehyde cross-linked chromatin prepared from wild type and Ring1a Ring1b dKO crypt cells and from WT ISCs using specific antibody against different target protein/modification.
Project description:We analyzed chromatin modifications, DNaseI-hypersensitive sites, and occupancy of a key secretory-lineage transcription factor, ATOH1. We found that lateral inhibition in the intestine occurs through ATOH1 exerting direct control within a broadly permissive chromatin state that is established in stem cells and is highly similar in specified progenitors of divergent potential. Mapping chromatin modifications (H3K4me2 and H3K27ac), DNaseI hypersensitivity (DHS), and ATOH1 binding sites in isolated intestinal crypt progenitors and mature intestinal villus cells.