Project description:The loss of TNFR1 (Tnfrsf1a) in the Il10-/- spontaneous mouse colitis background results in acceleration of disease onset. Whereas Il10-/- mice on the Bl/6 background are relatively protected from colitis throughout life, Il10-/- Tnfr1-/- mice develop colitis beginning at 4 wks of age. Their disease results in nearly 50% mortality by 12 wks of age. We hypothesized that this early-onset colitis was due to dysregulation of immune signals in early life, defining a key period known as the "weaning reaction" in which proinflammatory signals help induce mucosal tolerance of the microbiome. To test this hypothesis, we profiled, using mRNA-Seq, the colonic transcriptomes from Il10-/- and Il10-/- Tnfr1-/- mice at 2 wks of age. The results presented here show that Il10-/- Tnfr1-/- mice have reduced expression of cytokines at this early age, suggesting that they cannot amount an appropriate immune response. Thus, TNFR1 plays an important role in the weaning reaction and the acquisition of tolerance.
Project description:Athough anti-TNF therapies can be used to treat colitis associated with inflammatory bowel disease, in mice the loss of the TNF receptor TNFR1 (Tnfrsf1a) in the Il10-/- spontaneous colitis background results in acceleration of disease onset. Whereas Il10-/- mice on the Bl/6 background are relatively protected from colitis throughout life, Il10-/- Tnfr1-/- mice develop colitis beginning at 4 wks of age. Their disease results in nearly 50% mortality by 12 wks of age. Strikingly, Tnfr1-/- mice (with functional IL-10) exhibit evidence of mucosal dysfunction at 4 and 12 wks of age. These mucosal abnormalities include loss of barrier integrity, increased epithelial cell proliferation, crypt malformations, and increased immune cell infiltrate. Because of the early onset of mucosal abnormalities in Tnfr1-/- mice, with or without IL-10 expression, we hypothesized that TNFR1 plays important roles in colonic mucosal function in early life, prior to weaning. To test this hypothesis, we profiled, using mRNA-Seq, the colonic transcriptomes from wildtype and Tnfr1-/- mice at 2 wks of age. The results demonstrate that Tnfr1-/- mice have important gene expression changes, including reduced expression of Il1b, a marker of the proinflammatory "weaning reaction" that is required for establishment of mucosal tolerance in later life. TNFR1 therefore has key roles in colonic mucosal homeostasis in early life.
Project description:We have compared mRNA expression in full-thickness mouse colon between wildtype mice and mice with a genetic deletion in tumor necrosis factor receptor 1 (TNFR1, encoded by the Tnfrsf1a gene). This experiment was motivated by our observation that Il10-/- Tnfr1-/- double-knockout mice develop very-early-onset colitis at the time of weaning, significantly earlier than disease onset in Il10-/- single-knockout mice. This suggests that TNFR1 mediates protection from colitis. To understand these protective mechanisms at the transcript level in a non-inflammatory context, we performed transcriptome profiling (mRNA-Seq) on colons from 12-week-old Tnfr1-/- mice, which do not develop colitis, and wildtype littermates. These experiments revealed that an estimated 510 transcripts were upregulated and 377 downregulated in colonic tissue of Tnfr1-/- mice. We aggregated the transcript information to calculate gene expression and performed gene set enrichment analysis to identify signaling pathways altered in Tnfr1-/- mice. When queried against a high-confidence set of 50 signaling pathways, the Tnfr1-/- gene expression profile was associated with reduced mitosis and increased glycolysis, transforming growth factor beta signaling, DNA repair, and reactive oxygen species signaling. Gene ontological analysis classified some of the differentially expressed genes into cytokines, junctional proteins, and transcription factors, but within these groups there was no consensus on the direction of regulation. We also examined how differentially expressed transcripts (called the TNFR1-regulated transcriptome) compared to differentially expressed colonic transcripts from previously collected Tnfr2-/- animals (or the TNFR2-regulated transcriptome, available at the NCBI Gene Expression Omnibus under the accession GSE65408). The raw data were re-analyzed with the current pipeline to enable comparison. There was almost no correlation between TNFR1- and TNFR2-regulated transcripts. Only 30 (~3%) TNFR1-regulated transcripts were also TNFR2-regulated transcripts, and ~4% of the TNFR2-regulated genes were also TNFR1-regulated genes. Of the few co-regulated transcripts, there was a significant negative correlation in their direction of regulation in Tnfr1-/- versus Tnfr2-/- colons. Collectively these results indicate that TNFR1 and TNFR2 have mostly different and opposing effects on gene expression in the mouse colon. MANUSCRIPT ABSTRACT: BACKGROUND & AIMS: Very-early-onset inflammatory bowel disease (VEO-IBD) is a devastating disease beginning in early childhood, refractory to anti-tumor necrosis factor (anti-TNF) therapies, and associated with mutations in the interleukin 10 (IL-10) pathway. Contrary to mainstream clinical practice, cellular and animal studies have shown beneficial roles of TNF signaling in colitis, but how these roles are encoded through TNF’s receptors remains unknown. Here we examined the role of TNF receptor 1 (TNFR1, or p55) in modulating the onset and severity of colitis in the interleukin 10 (IL-10)-deficient mouse model. METHODS: Colitis severity was compared between Il10-/- Tnfr1-/- and Il10-/-- littermate mice at 2-12 weeks of age. To assess dysbiosis as a potential pathogenic mechanism, Il10-/- Tnfr1-/- mice were treated with neomycin and metronidazole and their cecal contents analyzed by 16S rRNA sequencing. Gene expression, barrier function, and epithelial proliferation and apoptosis were examined in adult colitis-free Tnfr1-/- wildtype littermates. RESULTS: In contrast to relatively healthy Il10-/- mice, Il10-/- Tnfr1-/- mice developed severe, antibiotic-treatable colitis shortly after weaning. Microbiotal composition was similar between Il10‑/- Tnfr1-/- mice and Il10-/- littermate controls. Tnfr1-/- mice expressed transcripts associated with reactive oxygen species and DNA repair pathways. Tnfr1-/- mice exhibited focal areas of crypt branching, higher colonic epithelial permeability, and hallmarks of DNA damage. CONCLUSIONS: TNFR1 promotes epithelial homeostasis and regulates commensal exposure. The lack of TNFR1 accelerates the onset and severity of IBD in the absence of tolerogenic signaling (i.e., lack of IL-10). Il10-/- Tnfr1-/- mice may serve as a valuable model of very-early-onset IBD (VEO-IBD).
Project description:Objetives: study and characterization of the IL10-/- knocked out colitis model in mice at genomic level and the study of the influence of bacteria in the development of the disease. Keywords: Differentially expressed genes analysis
Project description:Objetives: study and characterization of the IL10-/- knocked out colitis model in mice at genomic level and the study of the influence of bacteria in the development of the disease. Experiment Overall Design: We used three groups of animasl: 1)IL10-/- mice grown under conventional condition, 2)IL10-/- mice grown under specific pathogen free (SPF) conditions, 3) Wild type mice grown under conventional conditions (CONTROL group). For each group, we recovered samples at 7, 9 and 12 weeks after birth According to colon length and colonic damage, three replicates were selected for each time point and each group (27 samples), for genomic analysis. Experiment Overall Design: RNA was extracted from homogenized full-thickness colonic tissues in Trizol® reagent (Invitrogen) and purified with RNeasy affinity columns (Qiagen), according to manufacturer´s protocol. The microarray analysis was performed by Progenika Biopharma (Bilbao, Spain) on GeneChip® Rat Genome 230 2.0 Array (Affymetrix). All sample labeling (biotin), hybridization, staining and scanning procedures were carried out using Affimetrix, standard protocols (www.affymetrix.com). Normalization was carried out using Bioconductor sofware (affyPLM package).
Project description:The aim of this study is to compare the transcriptomic profile of colonic intestinal epithelial cells (IECs) at steady-state, and in several models of colitis: in naive wild-type C57BL/6 mice, in wild-type C57BL/6 mice treated for 7 days with 3% dextran sodium sulfate (DSS) in drinking water, in Il10-/- C57BL/6 mice and Il10-/- C57BL/6 mice with IEC-specific Rabgef1 deletion. Colonic IECs were isolated and FACS-sorted, then subjected tu bulk RNA-seq.
Project description:That commensal bacteria can influence intestinal inflammation has been observed using other models of chronic colitis. Loss of IL-10, a major immunosuppressive cytokine, induces spontaneous colitis in mice. The incidence of spontaneous polyp formation in IL-10-deficient mice was also completely eliminated in the absence of STING We used microarrays to evaluate the inflammatory cytokine expression in the colon from IL10 KO mice and IL10/STING KO mice.
Project description:Background: MicroRNAs (miRNAs) acting as negative regulators of gene expression are differentially expressed in intestinal tissues of patients with inflammatory bowel disease (IBD). Assessing the functional role of miRNAs in murine models of colitis facilitates elucidating the role of specific miRNAs in human IBD. The aim of this study was to determine the miRNA signature of murine models of colitis and to assess the influence of miR-21 on intestinal inflammation. Methods: miRNAs expression was accessed by microarray for acute and chronic murine model of colitis induced by DSS or TNBS. miR-21-deficient mouse and littermates controls were assessed in the standard DSS, TNBS and CD4+ T cell transfer models of colitis. RNAs of mouse colon and CD4+CD45RBHigh cells were analyzed by miRNA and mRNA microarray, and quantitative RT-PCR. Th1 polarization was accessed by flow-cytometry and ELISA. Results: Alterations of in miRNAs expression were identified for acute and chronic DSS colitis and TNBS colitis, receptively. The Expression of miRs-21, -142-3p and -223 was were distinct between DSS and TNBS models while overlap of numerous miRNAs was seen. Importantly, miRs-19b, -192 and -215, that are decreased in IBD, were significantly decreased in all 4 models of colitis. miR-21, which is increased in IBD, was increased in TNBS colitis but not the DSS colitis models. Further assessment of the miR-21-deficient 1-/- mice revealed that the deletion of miR-21 results in the exacerbation of both the TNBS and T cell-transfer models of colitis. Conclusions: miRNAs are differentially expressed in both human IBD and murine colitis, with overlap of several IBD-associated miRNAs. The demonstration that miR-21 deletion exacerbated CD4+ T cell-mediated models of colitis provides further evidence that miRNAs play significant roles in the pathogenesis of IBD. miRNAs expression was accesed for acute and chronic murine model of colitis induced by DSS or TNBS.Total of 20 samples with duplicates were analyed in this study.
Project description:Background: MicroRNAs (miRNAs) acting as negative regulators of gene expression are differentially expressed in intestinal tissues of patients with inflammatory bowel disease (IBD). Assessing the functional role of miRNAs in murine models of colitis facilitates elucidating the role of specific miRNAs in human IBD. The aim of this study was to determine the miRNA signature of murine models of colitis and to assess the influence of miR-21 on intestinal inflammation. Methods: miRNAs expression was accessed by microarray for acute and chronic murine model of colitis induced by DSS or TNBS. miR-21-deficient mouse and littermates controls were assessed in the standard DSS, TNBS and CD4+ T cell transfer models of colitis. RNAs of mouse colon and CD4+CD45RBHigh cells were analyzed by miRNA and mRNA microarray, and quantitative RT-PCR. Th1 polarization was accessed by flow-cytometry and ELISA. Results: Alterations of in miRNAs expression were identified for acute and chronic DSS colitis and TNBS colitis, receptively. The Expression of miRs-21, -142-3p and -223 was were distinct between DSS and TNBS models while overlap of numerous miRNAs was seen. Importantly, miRs-19b, -192 and -215, that are decreased in IBD, were significantly decreased in all 4 models of colitis. miR-21, which is increased in IBD, was increased in TNBS colitis but not the DSS colitis models. Further assessment of the miR-21-deficient 1-/- mice revealed that the deletion of miR-21 results in the exacerbation of both the TNBS and T cell-transfer models of colitis. Conclusions: miRNAs are differentially expressed in both human IBD and murine colitis, with overlap of several IBD-associated miRNAs. The demonstration that miR-21 deletion exacerbated CD4+ T cell-mediated models of colitis provides further evidence that miRNAs play significant roles in the pathogenesis of IBD. miRNAs expression was accesed for acute and chronic murine model of colitis induced by DSS or TNBS.Total of 20 samples with duplicates were analyed in this study.