Multi-omics characterization of inflammatory bowel disease induced hyperplasia/dysplasia in the Rag2-/- / Il10-/- mouse model [RNA-Seq]
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ABSTRACT: Epigenetic dysregulation is likely to play a role in the observed association between inflammatory bowel disease (IBD) and colon tumor development. In the present work, DNA methylome, hydroxymethylome, and transcriptome analyses were conducted in proximal colon tissues harvested from the Helicobacter hepaticus-infected murine model of IBD. Reduced representation bisulfite sequencing (RRBS) and oxidative RRBS (oxRRBS) analyses identified 1606 differentially methylated regions (DMR) and 3011 differentially hydroxymethylated (DhMR) regions. These DMR/DhMR overlapped with genes that are associated with gastrointestinal disease, inflammatory disease, and cancer. RNA-seq revealed pronounced expression changes of a number of genes associated with inflammation and cancer. Several genes (e.g. Duox2, Tgm2, Cdhr5, Hk2) exhibited both changes in DNA methylation/ hydroxymethylation and altered gene expression levels. Overall, our results suggest that chronic inflammation triggers changes in methylation and hydroxymethylation patterns in the genome, altering the expression of key tumorigenesis genes and potentially contributing to the initiation of colorectal cancer.
Project description:Epigenetic dysregulation is likely to play a role in the observed association between inflammatory bowel disease (IBD) and colon tumor development. In the present work, DNA methylome, hydroxymethylome, and transcriptome analyses were conducted in proximal colon tissues harvested from the Helicobacter hepaticus-infected murine model of IBD. Reduced representation bisulfite sequencing (RRBS) and oxidative RRBS (oxRRBS) analyses identified 1606 differentially methylated regions (DMR) and 3011 differentially hydroxymethylated (DhMR) regions. These DMR/DhMR overlapped with genes that are associated with gastrointestinal disease, inflammatory disease, and cancer. RNA-seq revealed pronounced expression changes of a number of genes associated with inflammation and cancer. Several genes (e.g. Duox2, Tgm2, Cdhr5, Hk2) exhibited both changes in DNA methylation/ hydroxymethylation and altered gene expression levels. Overall, our results suggest that chronic inflammation triggers changes in methylation and hydroxymethylation patterns in the genome, altering the expression of key tumorigenesis genes and potentially contributing to the initiation of colorectal cancer.
Project description:DNA methylation (5-mC) and hydroxymethylation (5-hmC) are regarded as important epigenetic hallmarks in the carcinogenesis of colorectal cancer by transcriptional regulation. 5hmC is an intermediate during active demethylation and maintains the equilibrium of DNA methylation. Previous studies on DNA methylation don’t differentiate 5-hmC from 5-mC. Here, in order to elucidate the epigenetic mechanisms of carcinogenesis of colorectal cancer, we integrate genome wide levels of 5-mC, 5-hmC and Transcriptional expression. 12 samples, including six colorectal tumor tissues and corresponding normal colonic tissues were recruited after surgery. Genome-wide DNA methylation was determined by methylated DNA immune- precipitation sequencing (MeDIP-seq), and hydroxymethylation by hydroxyl- methylated DNA immune-precipitation sequencing (hMedip-seq). Transcriptional expression was determined by RNA-seq. Group-wise different methylation region (DMR), different hydroxyl methylation region (DhMR) and different expressed gene (DEG) were identified. Epigenetic biomarkers were screened by integrating DMR, DhMR and DEG. We found that a genome-scale distinct hydroxymethylation pattern could be used as epigenetic biomarker for clearly differentiating colorectal cancer from normal tissues. 59249 differentially methylated regions (DMR), 187172 differentially hydroxymethylated region (DhMR) and 948 differentially expressed genes (DEGs) were identified. After cross-matched genes containing DMRs or DhMRs with DEGs, seven genes were screened. Furthermore, hypermethylation of HADHB was persistently found to be correlated with its down-regulation of transcription in CRC, potentially suggesting its role as TSG. The differences of methylation, hydroxymethylation and transcriptional expression in HADHB between cancerous and normal tissues were validated among additional colorectal cancer patients. To further validate this assumption, we also performed functional analysis and found that the expression of HADHB obviously reduced cancer cells migration and invasiveness. This study provided valuable basic data for screening epigenetic biomarkers and elucidated the epigenetic mechanisms of carcinogenesis of colorectal cancer.
Project description:Mitochondrial dysfunction is associated with inflammatory bowel diseases (IBD). To understand how microbial-metabolic circuits contribute to intestinal tissue injury, we disrupt mitochondrial function in the intestinal epithelium by deleting heat shock protein 60 (Hsp60Δ/ΔIEC). While metabolic perturbation causes self-resolving tissue injury, regeneration is disrupted in the absence of aryl hydrocarbon receptor (Hsp60Δ/ΔIEC;AhR-/-) or IL-10 (Hsp60Δ/ΔIEC;Il10-/-) leading to IBD-like pathology. Tissue pathology is absent in the distal colon of germfree (GF) Hsp60Δ/ΔIEC mice, highlighting bacterial control of metabolic injury. Selective colonization of GF Hsp60Δ/ΔIEC mice with the synthetic community OMM12 confirms expansion of metabolically-flexible Bacteroides ssp., which generates metabolic injury in mono-colonized mice. Transcriptional profiling of metabolically-impaired epithelium identifies gene signatures, such as Ido1, Nos2, and Duox2, differentiating active from inactive tissue inflammation in 343 tissue sections from Crohn’s disease patients. In conclusion, mitochondrial perturbation of the epithelium causes microbiota-dependent tissue injury and discriminative inflammatory gene profiles with relevance for IBD.
Project description:To investigate the genomic levels of 5-hydroxymethylcytosine at single-base resolution. The current study developed a method which allows one to study hydroxymethylation of cytosines in the genome via a subtractive method of RRBS and oxidative RRBS.
Project description:TET proteins convert 5-methylcytosine to 5-hydroxymethylcytosine, an emerging dynamic epigenetic state of DNA that can influence transcription. While Tet proteins have been associated to epigenetic repression or activation complexes, our understanding of the molecular mechanisms involved in Tet-mediated regulation of gene transcription remains limited. Here, we showed that Tet directly interact with lymphoid-specific helicase (Lsh), a chromatin remodelling factor belonging to the ISWI family. This specific interaction seems to regulate Tet enzymatic activity since Lsh knock-out leads to a substantial reduction of 5-hydroxymethylation global level in mouse embryonic fibroblasts (MEFs) and in embryonic stem cells (ES). Whole genome sequencing of 5hmC in wild-type versus Lsh knock-out MEFs and ESCs showed that in absence of Lsh some regions of the genome gain while others loose 5hmC marks, with a weak correlation to gene expression changes . We further demonstrated that 5hmC modifications upon Lsh loss are not a direct consequence of 5mC decrease as DhMR (differentially hydroxymethylated regions) did not overlap with DMR (differentially methylated regions) underlying that these modifications occurred at different genomic loci. Altogether, our results suggest that DNA 5-hydroxymethylation and nucleosome folding are linked phenomena, highlighting novel means by which Tet proteins may influence gene regulation.
Project description:Crohn’s disease (CD) is a complex chronic inflammatory disorder with both gastrointestinal and extra-intestinal manifestations associated immune dysregulation. Analyzing 202,359 cells from 170 specimens across 83 patients, we identified a distinct epithelial cell type in both terminal ileum and ascending colon (termed “LND”) with high expression of LCN2, NOS2, and DUOX2 and genes related to antimicrobial response and immunoregulation. LND cells, confirmed by in-situ RNA and protein imaging, were rare in non-IBD controls but significantly expanded in active CD. These cells actively interacted with immune cells and specifically expressed IBD/CD susceptibility genes, as demonstrated by multimodal data, suggesting a possible role in CD immunopathogenesis. Furthermore, we discovered early and late LND subpopulations with different origins and developmental potential. A higher ratio of late to early LND cells correlated with better response to anti-TNF treatment. These findings suggest a potential pathogenic role for LND cells in both Crohn’s ileitis and colitis.
Project description:Using single-cell RNA-seq of colon lamina propria leukocytes (LPL), together with ATAC-seq, ChIP-seq and RNA-seq from colon LPL and sorted CD4+ T from colon lamina propria during oral infection with the pathobiont Helicobacter hepaticus we show that Blimp-1 and c-Maf both positively regulate Il10 gene expression, but also cooperate to negatively regulate a large network of proinflammatory effector genes in T cells. While T cell-specific deletion of either Prdm1, Maf or both transcription factors did not result in overt inflammation of the colon at steady state, H. hepaticus infection resulted in mild/moderate colitis in both the Prdm1fl/flCd4Cre and Maffl/flCd4Cre single T cell-specific transcription factor deficient mice, while the double knockout Prdm1fl/flMaffl/flCd4Cre infected mice suffered severe colitis and showed a massive increase in T cell effector genes in colonic LPL. Blimp-1 and c-Maf cooperate to negatively regulate genes including Ifng, Csf2, Il23r, Stat4, Il18r1 and Il2rg, and deletion of both these transcription factors in T cells translated to an exacerbated pathogenic TH1, IFN-g+GM-CSF+ effector cell response. c-Maf, additionally negatively regulated Il17a expression which was elevated in the LPL as assessed by bulk RNA-seq and scRNA-Seq analysis in the H. hepaticus infected Maffl/flCd4Cre mice.
Project description:Using single-cell RNA-seq of colon lamina propria leukocytes (LPL), together with ATAC-seq, ChIP-seq and RNA-seq from colon LPL and sorted CD4+ T from colon lamina propria during oral infection with the pathobiont Helicobacter hepaticus we show that Blimp-1 and c-Maf both positively regulate Il10 gene expression, but also cooperate to negatively regulate a large network of proinflammatory effector genes in T cells. While T cell-specific deletion of either Prdm1, Maf or both transcription factors did not result in overt inflammation of the colon at steady state, H. hepaticus infection resulted in mild/moderate colitis in both the Prdm1fl/flCd4Cre and Maffl/flCd4Cre single T cell-specific transcription factor deficient mice, while the double knockout Prdm1fl/flMaffl/flCd4Cre infected mice suffered severe colitis and showed a massive increase in T cell effector genes in colonic LPL. Blimp-1 and c-Maf cooperate to negatively regulate genes including Ifng, Csf2, Il23r, Stat4, Il18r1 and Il2rg, and deletion of both these transcription factors in T cells translated to an exacerbated pathogenic TH1, IFN-g+GM-CSF+ effector cell response. c-Maf, additionally negatively regulated Il17a expression which was elevated in the LPL as assessed by bulk RNA-seq and scRNA-Seq analysis in the H. hepaticus infected Maffl/flCd4Cre mice.
Project description:Using single-cell RNA-seq of colon lamina propria leukocytes (LPL), together with ATAC-seq, ChIP-seq and RNA-seq from colon LPL and sorted CD4+ T from colon lamina propria during oral infection with the pathobiont Helicobacter hepaticus we show that Blimp-1 and c-Maf both positively regulate Il10 gene expression, but also cooperate to negatively regulate a large network of proinflammatory effector genes in T cells. While T cell-specific deletion of either Prdm1, Maf or both transcription factors did not result in overt inflammation of the colon at steady state, H. hepaticus infection resulted in mild/moderate colitis in both the Prdm1fl/flCd4Cre and Maffl/flCd4Cre single T cell-specific transcription factor deficient mice, while the double knockout Prdm1fl/flMaffl/flCd4Cre infected mice suffered severe colitis and showed a massive increase in T cell effector genes in colonic LPL. Blimp-1 and c-Maf cooperate to negatively regulate genes including Ifng, Csf2, Il23r, Stat4, Il18r1 and Il2rg, and deletion of both these transcription factors in T cells translated to an exacerbated pathogenic TH1, IFN-g+GM-CSF+ effector cell response. c-Maf, additionally negatively regulated Il17a expression which was elevated in the LPL as assessed by bulk RNA-seq and scRNA-Seq analysis in the H. hepaticus infected Maffl/flCd4Cre mice.
Project description:Colon gene expression in human IBD. The three major clinical subsets of Inflammatory Bowel Disease (IBD) include colon-only Crohn's Disease (CD), ileo-colonic CD, and Ulcerative Colitis (UC). These experiments tested differential colon gene expression in these three types of IBD, relative to healthy control samples, and the local degree of mucosal inflammation as measured by the CD Histological Index of Severity (CDHIS). Colon biopsy samples were obtained from IBD patients at diagnosis and during therapy, and healthy controls. The global pattern of gene expression was determined using GeneSpring software, with a focus upon candidate genes identified in a recent genome wide association study in pediatric onset IBD. Data suggested that two of these candidate genes are up regulated in pediatric IBD, partially influenced by local mucosal inflammation. These experiments tested differential colon gene expression in healthy, CD, and UC samples for candidate genes identified in a recent pediatric onset IBD genome wide association study. Keywords: Single time point in CD and UC and healthy controls.