Transcriptional profiling of small intestinal crypts from mice treated with Notch blocking antibodies or Notch blocking antibodies in combination with an Lrp6 blocking antibody.
Ontology highlight
ABSTRACT: The goal of this study was to identify genes that are differentially expressed during a 24 hour Notch blockade and whether a Wnt antagonist (anti-Lrp6) could block this effect. 3 condition experiment, Control untreated compared to N1N2 treated, and N1N2 treated compared to N1N2_Lrp6 treated. 5 biological replicates per condition.
Project description:Polycomb-mediated gene repression plays an important role in adult stem cell maintenance. We knocked out (using the inducible AhCre-LoxP system) Polycomb genes Eed and Ezh2 in the intestine for 6 weeks, after which crypts - the small intestinal stem cell zone - were harvested and RNA sequenced. We found Wnt, Notch and cell cycle pathways to be affected in Eed knockout (KO) but not Ezh2 KO crypts. Direct targets of Eed were determined by comparing this data with ChIP-sequencing. Small intestinal crypt mRNA profiles of 6 weeks-induced 12 weeks old Eed KO, Ezh2 KO and WT mice (all triplicates) as well as 10 days-induced Eed KO and WT organoids (duplicates) were generated by RNA sequencing over two runs and using IlluminaHiseq2000 and Hiseq2500.
Project description:We wanted to assess the role of a specific smooth muscle protein (MMP17) in two different intestinal compartments, the epithelium (crypts) and the smooth muscle. To do that we isolate intestinal crypts from wild-type (WT) and knockout (KO, Mmp17-/-) mice, and obtained clean strips of smooth muscle. After muscle dissociation, we obtained RNA directly from crypts and muscle, and it was used for RNA-seq. By comparing WT and KO samples we observed a higher impact in gene expression affecting crypts, even though MMP17 is only expressed in muscle. This helped us to identify altered signaling pathways in KO crypts that linked MMP17 with SMAD4 and BMP signaling.
Project description:The transcription factor Twist is a critical cooperating factor that confers transcriptional specificity to the Notch pathway in muscle progenitor cells (DmD8) ChIP analysis of Twi show that Twist binding is significantly enriched in Notch responsive region in DmD8 cells 3 replicates of Twist ChIP after30 min. Notch activation.
Project description:The goal of this study was to identify genes that are differentially expressed during a 24 hour Notch blockade and whether a Wnt antagonist (anti-Lrp6) could block this effect.
Project description:Polycomb-mediated gene repression plays an important role in adult stem cell maintenance. Direct targets of the Polycomb repressive complex PRC2 in th intestinal epithelium were revealed by performing ChIP-sequencing on crypt samples isolated from wild type murine small intestines. The resulting list of H3K27me3-enriched genes were compared with RNA-sequencing data from wild type and Eed knockout crypts. Crypts were isolated from wild type murine intestinal epithelium and subjected to ChIP using anti-H3K27me3 and anti-H3K27Ac antibodies, after which DNA isolated from extracted immunocomplexes was sequenced.
Project description:Notch signalling occurs via direct cell-cell interactions and plays an important role in linking the fates of neighbouring cells. There are four different mammalian Notch receptors that can be activated by five cell surface ligands. The ability to inhibit specific Notch receptors would help identify the roles of individual family members and potentially provide a means to study and control cell differentiation. Anti-Notch antibodies in the form of single chain Fvs were generated from an antibody phage display library by selection on either the ligand binding domain or the negative regulatory region (NRR) of Notch1 and Notch2. Six antibodies targeting the NRR of Notch1 and four antibodies recognising the NRR of Notch2 were found to prevent receptor activation in cell-based luciferase reporter assays. These antibodies were potent, highly specific inhibitors of individual Notch receptors and interfered with endogenous signalling in stem cell systems of both human and mouse origin. Antibody-mediated inhibition of Notch efficiently down-regulated transcription of the immediate Notch target gene hairy and enhancer of split 5 (Hes5) in both mouse and human neural stem cells and revealed a redundant regulation of Hes5 in these cells as complete down-regulation was seen only after simultaneous blocking of Notch1 and Notch2. In addition, these antibodies promoted differentiation of neural stem cells towards a neuronal fate. In contrast to the widely used small molecule γ-secretase inhibitors, which block all 4 Notch receptors (and a multitude of other signalling pathways), antibodies allow blockade of individual Notch family members in a highly specific way. Specific inhibition will allow examination of the effect of individual Notch receptors in complex differentiation schemes regulated by the co-ordinated action of multiple signalling pathways.
Project description:Cellular responses to signalling pathways are often highly dynamic, however most analyses of developmental signalling pathways focus on a single endpoint. Here we have analyzed the temporal changes in transcription following a short Notch activation treatment and have related these to the recruitment of the Notch pathway transcription factor, CSL [Suppressor of Hairless, Su(H), in Drosophila], and to the state of RNA Polymerase II (Pol II) binding. A total of 154 genes showed significant differential expression over time and their expression profiles stratified into 14 clusters based on temporal and quantitative differences in their responses. These differences were partially reflected in the profiles of Pol II and Su(H) binding. However neither could fully account for the different response profiles. Furthermore, the timing of the different responses was unaffected by more prolonged Notch activation. Instead our data suggest that regulatory relationships between genes that segregate into different response clusters can partially account for the stratification. Thus feed-forward repression, where products of early responding Enhancer of split bHLH genes (E(spl)bHLH) inhibit expression of endogenous repressors, is one mechanism that explains the profile of genes that exhibit delayed up-regulation. E(spl)bHLH genes may therefore be responsible for co-ordinating the Notch response of a wide spectrum of other targets, explaining their critical functions in many developmental and disease contexts. DmD8 cells were cultured in Schneiders medium (Invitrogen) supplemented with 10% FBS (Sigma), 5ug/ml insulin (Sigma) and 5% penicillin / streptomycin (Sigma) according to standard protocols. Notch signalling was initiated by replacing cell media with 2mM EDTA in PBS. The cells were stimulated for 5 minutes before washing out EDTA using normal culture media. The cells were then collected at 18 time points at 0M-bM-^@M-^Y, 5M-bM-^@M-^Y, 10M-bM-^@M-^Y, 15M-bM-^@M-^Y, 20M-bM-^@M-^Y, 25M-bM-^@M-^Y, 30M-bM-^@M-^Y, 35M-bM-^@M-^Y, 40M-bM-^@M-^Y, 50M-bM-^@M-^Y, 60M-bM-^@M-^Y, 70M-bM-^@M-^Y, 80M-bM-^@M-^Y, 90M-bM-^@M-^Y, 100M-bM-^@M-^Y, 110M-bM-^@M-^Y, 120M-bM-^@M-^Y and 150M-bM-^@M-^Y after stimulation in 4 independent time trials. For control samples, for each time trial, media was replaced with fresh media to mimic the addition and removal of EDTA in corresponding experimental samples and then collected at equivalent times. For each trial 50 M-BM-5g of the untreated control RNA sample of each time point was pooled to create a trial specific reference sample. Samples from trials #1 and #3 were labelled with Cy5 and trails #2 and #4 as dye-swap with Cy3.
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.