Project description:Gene expression analysis of sorted colon macrophages of Rictor fl/fl LysM+/+ and Rictor fl/fl LysM+/cre mice Dysregulations of immune and metabolic processes can lead to chronic inflammation, which is one of the driving forces for the development of cancer. Macrophages are regulators of these processes and therefore have a fundamental role for the initiation of cancer. Here we find that deletion of Rictor in myeloid cells increases tumor number and size in the colitis-associated colorectal cancer model and leads to a stronger inflammatory response in the underlying acute DSS-colitis model. OPN is shown to be upregulated in the serum of myeloid-specific Rictor-KO mice during the DSS-colitis and the more severe phenotype, characterized by decreased survival, increased weight loss, shorter colons and enhanced infiltration of immune cells into the colon, can be reverted by the neutralization of OPN in these mice. Microarray analysis reveals a change in inflammatory and metabolic gene signatures of Rictor-KO colon macrophages that is also seen in the Rictor-KO BMDM in vitro. Therefore, our data show that myeloid Rictor controls macrophage polarization and the cellular energy metabolism, thereby suppressing colitis and colitis-associated colorectal cancer.
Project description:To uncover molecular mechanisms specifically involved in the pathogenesis of colitis-associated colon cancer (CAC), we studied tumorigenesis in experimental models of CAC and sporadic CRC that mimic characteristics of human CRC. Using comparative whole genome expression profiling, we observed differential expression of epiregulin (Ereg) in mouse models of colitis-associated, but not sporadic colorectal cancer. Similarly, highly significant upregulation of Ereg expression was found in cohorts of patients with colitis-associated cancer in inflammatory bowel disease but not in sporadic colorectal cancer. Furthermore, tumor-associated fibroblasts were identified as major source of Ereg in colitis-associated neoplasias. Functional studies showed that Ereg-deficient mice, although more prone to colitis, are strongly protected from colitis-associated tumors, and data from serial endoscopic studies revealed that Ereg promotes growth rather than initiation of tumors. 4 samples of individual distal colitis-associated tumors (CAC) from 4 mice, 2 samples of tumor-free distal colon epithelium with a pool of 5 mice per sample (CAC contr), 5 samples of individual Apcmin/+ tumors from the distal colorectum of 5 mice (sporCRC) and 3 samples of tumor-free distal colon epithelium (pool of 4 mice per sample) (sporCRC contr). Colitis-associated tumorigenesis was performed by intraperitoneal injection of Azoxymethane (10mg/kg) (Sigma) into C57BL/6J wildtype mice followed by 3 cycles of Dextran Sodium Sulfate (DSS) in drinking water. Each DSS-cycle was composed of DSS (2.5% (w/v) (MP Biomedicals) in drinking water for 7 days, followed by a recovery phase with regular drinking water for 14 days. Sporadic tumors were from C57BL/6J-ApcMin/+/J mice. All tumors were obtained from the from the lower 6th of the large intestine and they had the same size covering between ¼ and up to ½ of the colonic circumferenc as evaluated by mini-endoscopy.
Project description:In this study, to investigate the role of macrophage GIV in the colon, Katkar et al. employed a myeloid-specific GIV-KO (Ccdc88afl/fl/LysMCre) mouse model to analyze colon transcriptomic data from wild-type (WT) and macrophage-specific GIV-KO mice treated with dextran sulfate sodium (DSS) colitis, with or without muramyl dipeptide (MDP) treatment.
Project description:This study aims to investigate the protein expression profiles in a murine model of dextran sulfate sodium (DSS)-induced colitis using advanced Astral-DIA quantitative proteomics technology. A total of 12 colon tissue samples were analyzed, including 6 from healthy control mice and 6 from DSS-treated mice with induced colitis. Experimental Design Species: Mus musculus (C57BL/6 strain). Tissue Source: Colon tissues were dissected, snap-frozen in liquid nitrogen, and homogenized to extract proteins. Groups: Control Group: Healthy mice without intervention. DSS Group: Mice subjected to 2.5% DSS administration for 7 days to induce colitis, validated by histopathological assessment.
Project description:Dextran sodium sulfate (DSS) causes inflammation in the gut similar to ulcerative colitis in humans. Patients with ulcerative colitis have increased risk of developing colon cancer. We sought to determine which genes are altered in the normal colonic epithelium, and which changes depend on the Pirc mutation. 97 day old (ACIxF344)F1 wild type and Pirc male rats either untreated or given 4% DSS in the drinking water from 40-47 and 54-61 days of age, housed in 12 hour light:12 dark, ad lib feeding. Normal colonic tissue was collected from the distal colon at 97 days of age.
Project description:This study identifies a novel mechanism linking IL-17A with colon tissue repair and tumor development. Abrogation of IL-17A signaling mice attenuated tissue repair of DSS-induced damage in colon epithelium and markedly reduced tumor development in AOM/DSS model of colitis-associated cancer. The goal of these studies is to identify genes associated with IL-17RC deficiency during AOM-DSS induced tumorigenesis
Project description:Increased levels of tissue inhibitor of metalloproteinase-1 (TIMP-1) have been detected in fibrotic strictures in Crohnâs disease. In a murine model of chronic inflammation, fibrosis was associated with an increase in TIMP-1 and inhibition of matrix metalloproteinase (MMP)-mediated degradation. We investigated the effect of TIMP-1 deficiency on the colonic gene expression in acute and chronic murine models of colitis, using whole genome gene expression arrays. Colitis was induced via oral administration of dextran sodium sulphate (DSS) to B6.129S4-Timp1tm1Pds/J knock-out (KO) and C57BL/6J wild-type (WT) mice. Total RNA extracted from snap frozen colon was used to analyze mRNA expression via Affymetrix Mouse Gene 1.0 ST Arrays