Dynamic changes in chromatin states during specification and differentiation of adult intestinal stem cells [k27m3]
Ontology highlight
ABSTRACT: To determine chromatin changes associated with ISCs specification we performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) using 2x105 FACS purified E12.5 or E14.5 embryonic intestinal epithelial cells, Lgr5+ adult ISCs and enterocytes.
Project description:To determine chromatin changes associated with ISCs specification we performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) using 2x105 FACS purified E12.5 or E14.5 embryonic intestinal epithelial cells, Lgr5+ adult ISCs and enterocytes.
Project description:To determine chromatin changes associated with ISCs specification we performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) using 2x10e5 FACS purified E12.5 or E14.5 embryonic intestinal epithelial cells, Lgr5+ adult ISCs and enterocytes.
Project description:To determine chromatin changes associated with ISCs specification we performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) using 2x10e5 FACS purified E12.5 or E14.5 embryonic intestinal epithelial cells, Lgr5+ adult ISCs and enterocytes.
Project description:To follow the changes in the transcriptional programs accompanying the specification, maintenance and differentiation of the adult ISCs we sequenced whole transcriptomes of embryonic intestinal epithelium progenitors (at E12.5 and E14.5), adult ISCs and their differentiated progenies, the majority of which are absorptive enterocytes. EpCAM positive embryonic gut epithelium was isolated from dissected small intestines using fluorescence activated cell sorting (FACS). Adult ISCs were purified on the basis of GFP fluorescence from crypts of Lgr5GFP-Cre-ERT mice (Barker et al. 2007), whereas enterocytes (EpCAM+ CD45- CD31-) were isolated from villi.
Project description:Perturbed intestinal epithelial homeostasis demonstrated as decreased Lgr5+ intestinal stem cells (Lgr5 ISCs) and increased secretory lineages were observed in our study where Lkb1 was specfically deleted in Lgr5 ISCs using Lgr5-EGFP-creERT2 (Tamoxifen) deletor. To gain mechanistic insight how Lkb1 maintains intestinal epithelial stem cell homeostasis, Lkb1 deficient ISCs (Lgr5-high cells) and progenitors (Lgr5-low cells) are isolated by flow cytometry and profiled by RNA sequencing to compare with controls (Lkb1 wild type ISCs and progenitors).
Project description:To follow the changes in the transcriptional programs accompanying the specification of the adult ISCs we sequenced whole transcriptomes of embryonic intestinal epithelium progenitors (at E11.5 and E12.5) and adult ISCs. EpCAM positive embryonic gut epithelium was isolated from dissected small intestines using fluorescence activated cell sorting (FACS). Adult ISCs were purified on the basis of GFP fluorescence from crypts of Lgr5GFP-Cre-ERT mice (Barker et al. 2007) Double positive adlut ISCs were isolated by FACS based on GFP and tdTomato fluorescence.
Project description:The small intestine is a rapidly proliferating organ that is maintained by a small population of Lgr5-expressing intestinal stem cells (ISCs). However, several Lgr5-negative ISC populations have been identified, and this remarkable plasticity allows the intestine to rapidly respond to both the local environment and to damage. The mediators of such plasticity are still largely unknown. Using intestinal organoids and mouse models, we show that upon ribosome impairment (driven by Rptor deletion, amino acid starvation, or low dose cyclohexamide treatment) ISCs gain an Lgr5-negative, fetal-like identity. This is accompanied by a rewiring of metabolism. Our findings suggest that the ribosome can act as a sensor of nutrient availability, allowing ISCs to respond to the local nutrient environment. Mechanistically, we show that this phenotype requires the activation of ZAKɑ, which in turn activates YAP, via SRC. Together, our data reveals a central role for ribosome dynamics in intestinal stem cells, and identify the activation of ZAKɑ as a critical mediator of stem cell identity.
Project description:Intestinal stem cells (ISC) encounter inflammatory insults in immune mediated gastro-intestinal (GI) diseases. It remains unknown whether, and how, they adapt, and if the adaptation leaves scars on the ISCs that affects their subsequent regeneration capacity. We investigated the consequences of inflammation on Lgr5+ISCs in well-defined clinically relevant models of gastro-intestinal acute graft-versus-host disease (GI GVHD). Utilizing single cell transcriptomics, organoid, metabolic, epigenomic and in vivo models we found that Lgr5+ISCs undergo metabolic changes that lead to accumulation of succinate, which reprograms its epigenome. We performed transposase-accessible chromatin sequencing (ATAC-seq) in sorted Lgr5+ISCs harvested from the BALB/c→B6-GFP-Lgr5 model of GVHD.
Project description:We demonstrate that Bmi1-expressing cells represent the predominant epithelial ISC in early intestinal development and precede existence of the canonical Wnt-dependent Lgr5+ stem cell population. We reveal that early in development, Bmi1+ ISCs are highly proliferative, then transition to a slow-cycling state with the emergence of the Lgr5+ ISC. Combining single cell RNA-sequencing (scRNA-seq) with bulk population ATAC-seq (Assay for Transposase Accessible Chromatin sequencing) analyses, we identify that a non-canonical Wnt signaling pathway correlates with the temporal presence of the highly proliferative developmental Bmi1+ ISC population.