Project description:Histone acetyltransferases KAT2A and KAT2B are paralogs highly expressed in the intestinal epithelium, but their functions are not well understood. In this study, double knockout of murine Kat2 genes in the intestinal epithelium was lethal, resulting in diminished H3K9ac
expression, loss of stem cells, and robust activation of interferon signaling. Use of pharmacological agents and sterile organoid cultures indicated a cell-intrinsic double-stranded RNA trigger for interferon signaling. Acetyl-proteomics and dsRIP-seq were employed to interrogate the mechanism behind this response, which identified self-derived, mitochondria- encoded double-stranded RNA as the source of intrinsic interferon signaling. KAT2A and KAT2B therefore play an essential role in regulating mitochondrial functions as well as maintaining intestinal health.
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:To define target genes of the intestine-restricted transcription factor (TF) CDX2 in intestinal stem cells, we performed chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-Seq). We used RNA-sequencing to profile gene expression changes during cell differentiation from mouse intestinal stem cells to mature villus cells, as well as genes perturbed in intestinal stem cells upon loss of Cdx2. We find thousands of genes that change in expression during cell differentiation, including known stem cell and mature markers. Upon loss of Cdx2, hundreds of genes are up and down-regulated in intestinal stem cells, some of which are also bound by CDX2 nearby and constitute candidate direct target genes. CDX2 ChIP-Seq analysis of isolated mouse intestinal stem cells. RNA seq analysis of control mouse villus cells, control intestinal stem cells and Cdx2-deleted intestinal stem cells.
Project description:RNA-seq was performed on FACS-isolated stem cells from the mouse intestinal epithelium. The purpose of the experiment was to compare the transcriptomes of stem cells enriched for recently generated (young) mitochondria and stem cells enriched with old mitochondria. The dataset also includes samples of stem cells with young mitochondria deliberately contaminated with a small amount of Paneth cells, to control for accidental Paneth cell contamination in the sorting scheme.
