Project description:Abstract. Background: The cause of ulcerative colitis (UC) is not yet fully understood. Previous research has pointed towards a potential role for mutations in NOD2 in promoting the onset and progression of inflammatory bowel disease (IBD) by altering the microbiota of the gut. However, the relationship between toll-like receptor 4 (TLR4) and gut microbiota in IBD is not well understood. To shed light on this, the interaction between TLR4 and gut microbiota was studied using a mouse model of IBD. Methods: To examine the function of TLR4 signaling in intestinal injury repair, researchers developed Dextran Sulfate Sodium Salt (DSS)-induced colitis and injury models in both wild-type (WT) mice and TLR4 knockout (TLR4-KO) mice. To assess changes in the gut microbiota, 16S rRNA sequencing was conducted on fecal samples from both the TLR4-KO and WT enteritis mouse models. Results: The data obtained depicted a protective function of TLR4 against DSS-induced colitis. The gut microbiota composition was found to vary considerably between the WT and TLR4-KO mice groups as indicated by β-diversity analysis and operational taxonomic units (OTUs) cluster. Statistical analysis of microbial multivariate variables depicted an elevated abundance of Escherichia coli/Shigella, Gammaproteobacteria, Tenerlcutes, Deferribacteres, Enterobacteria, Rikenellaceae, and Proteobacteria in the gut microbiota of TLR4-KO mice, whereas there was a considerable reduction in Bacteroidetes at five different levels of the phylogenetic hierarchy including phylum, class, order, family, and genus in comparison with the WT control. Conclusion: TLR4 may protect intestinal epithelial cells from damage in response to DSS-induced injury by controlling the microbiota in the gut.
Project description:Amelioration of AOM/DSS-induced murine colitis-associated cancer by Evodiamine intervention is primarily associated with gut microbiota-metabolism-Inflammatory signaling axis
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are using transcriptome profiling (RNA-seq) to evaluate the effects of anti-S100a9 antibody on the global transcriptome of the colon tissues of the AOM/DSS mouse model (a model that mimics the human colitis-associated colon cancer development). Methods: 36 five-week-old male ICR mice were randomized divided into three groups: control (i.e. no AOM/DSS and antibody treatment), AOM/DSS+IgG Ab (1.5 mg/kg), and AOM/DSS+anti-S100a9 Ab (1.5 mg/kg). Mice were intraperitoneal injected with a single dose of 10 mg/kg azoxymethane (AOM) (A5486; Sigma) on day 1. One week after the AOM injection, mice were given three cycles of DSS (cycle 1: 2%, 7 days; cycle 2: 1.5%, 5 days; and cycle 3: 1.5%, 5 days, DSS: 36–50 kDa; MP Biomedicals, CA, USA) in their drinking water, and then distilled water until the end of the experiment. Antibodies were administrated intravenously every two days during the three cycles of DSS treatment. Mice were sequentially killed randomly at the end of the 18th week, and at least five mice were killed for each group at each time point. RNAs were extracted by Trizol and sequenced by Solexa high-throughput sequencing service (Oebiotech, Shanghai, China). Data were extracted and normalized according to the manufacturer’s standard protocol.Each group has three mices' colon tissues be tested. Results: Log-fold changes of up- or down-regulated mRNAs between the control and experiment group were selected with a significance threshold of p<0.05. There are 1017 mRNAs were up-regulated and 815 were down-regulated in “AOM/DSS+IgG Ab" group comparing to “control" group. There are 385 mRNAs were up-regulated and 163 were down-regulated in “AOM/DSS+anti-S100a9 Ab" group comparing to “control" group. There are 1314 mRNAs were up-regulated and 968 were down-regulated in “AOM/DSS+anti-S100a9 Ab" group comparing to “AOM/DSS+IgG Ab". Conclusions: Our study describes the global transciptome changes of colon tissues of the AOM/DSS mouse model induced by anti-S100a9 antibody treatment.
Project description:This study uses whole-transcriptome sequencing to characterize the transcriptomes of the AOM/DSS mouse model. In this model, mice are treated with dextran sodium sulfate (DSS) to induce colitis. When this treatment is preceded by injections of the weak carcinogen azoxymethane (AOM) the mice develop intestinal tumors. Our results identify sets of differentially expressed genes which are correlated with methylation changes of the corresponding genes. Whole transcriptome analysis of Mus musculus. Three conditions were sequenced and analyzed, the first is an untreated control, the second corresponds to inflammation induced by applying DSS, the third to cancer induced by inflammation and application of AOM. The control condition as well as the AOM-induced cancer condition were analyzed using three replicates, the second condition using 4 replicates.
Project description:To find out which miRNAs are significantly differential expression and potentially involved in the process of inflammation promoting carcinogenesis of colorectal cancer (CRC). We established a colitis-associated CRC (AOM/DSS, Azoxymethane/Dextran sulfate sodium salt) model, colitis (DSS) model and high dose carcinogen (AOM, about 5 times AOM amount given than AOM/DSS model) model. At day 100 when tumor formed in AOM/DSS bearing mice (colitis-associated CRC mice) but no tumor was found in AOM (high dose carcinogen) and DSS model, we employed miRNA microarray as a discovery platform to identify genes with the potential to involve in the progression of CRC promoted by inflammation. 5-7 weeks female BALB/c mice, (1) AOM/DSS group: AOM 12.5mg/kg i.p. at day 1, DSS drinking 5d/21dx3circles from day 5; (2) AOM group: AOM 10mg/kg i.p. 1/weekx6 from day 1; (3) DSS group: DSS drinking 5d/21dx3circles from day 5. The distal colon epithelial tissues were collected at day100 when tumor formed in AOM/DSS bearing mice. The miRNA microarray experiments were performed together.
Project description:Inflammation is highly associated with colon carcinogenesis. Epigenetic mechanisms play an important role in the initiation and progression of colon cancer. Curcumin is a dietary cancer preventive phytochemical with promising effect in suppressing colitis-associated colon cancer (CAC) in azoxymethane (AOM) and dextran sulfate sodium (DSS) mouse model. In the present study, we confirmed the effect of curcumin in suppressing colon cancer. Using Agilent SureSelect Methyl-seq and RNA-seq, we obtained single-base methylation profile and transcriptome analyses of epithelial cells from control group, AOM and DSS induced group (AOM+DSS), and AOM and DSS induced plus curcumin treated group (AOM+DSS+Curcumin) in a 18 weeks long-term colon cancer mouse model. The average DNA methylation levels of the three groups are significantly different also. Based on differential methylation patterns of three groups, several pathways of genes were identified including IL-8 signaling, LPS-stimulated MAPK signaling and colorectal cancer metastasis signaling. Among these methylated pathways and genes, Tnf, an inflammatory gene stood out with decreased DNA CpG methylation in the AOM-DSS as compared to the control group and interestingly curcumin reversed the CpG methylation (validated by pyrosequencing). The functional role of DNA methylation of Tnf was confirmed by in vitro luciferase transcriptional activity assay. In addition, we found that a group of genes associated with the inflammatory responses and their methylation level was decreased in AOM+DSS group but restored in the curcumin treated group. Taken together, in this study, aberrant DNA CpG methylation of the inflammatory response was found in colitis-associated colon cancer and curcumin restored their CpG methlyation, which could potentially explain the inflammatory and cancer protective effects of curcumin. (Note this GEO/dataset is the DNA methyl-seq part of the study.)
Project description:To find out which mRNAs are significantly differential expression and potentially involved in the process of inflammation promoting carcinogenesis of colorectal cancer (CRC). We established a colitis-associated CRC (AOM/DSS, Azoxymethane/Dextran sulfate sodium salt) model, colitis (DSS) model and high dose carcinogen (AOM, about 5 times AOM amount given than AOM/DSS model) model. At day 100 when tumor formed in AOM/DSS bearing mice (colitis-associated CRC mice) but no tumor was found in AOM (high dose carcinogen) and DSS model, we employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to involve in the progression of CRC promoted by inflammation. 5-7 weeks female BALB/c mice, (1) AOM/DSS group: AOM 12.5mg/kg i.p. at day 1, DSS drinking 5d/21dx3circles from day 5; (2) AOM group: AOM 10mg/kg i.p. 1/weekx6 from day 1; (3) DSS group: DSS drinking 5d/21dx3circles from day 5. The distal colon epithelial tissues were collected at day100 when tumor formed in AOM/DSS bearing mice. The whole genome microarray expression profiling experiments were performed together.
Project description:To find out which miRNAs are significantly differential expression and potentially involved in the process of inflammation promoting carcinogenesis of colorectal cancer (CRC). We established a colitis-associated CRC (AOM/DSS, Azoxymethane/Dextran sulfate sodium salt) model, colitis (DSS) model and high dose carcinogen (AOM, about 5 times AOM amount given than AOM/DSS model) model. At day 100 when tumor formed in AOM/DSS bearing mice (colitis-associated CRC mice) but no tumor was found in AOM (high dose carcinogen) and DSS model, we employed miRNA microarray as a discovery platform to identify genes with the potential to involve in the progression of CRC promoted by inflammation.
Project description:Microbiota dysbiosis and mucosa-associated bacteria are involved in colorectal cancer (CRC) progression. However, the temporal changes in commensal-derived pathobionts and host-microbe interactions remain poorly understood. Our study demonstrated that antibiotic (ABX) treatment at a mid phase but not at early or late time points reduced tumor burden in a chemically induced CRC mouse model. A transient surge in fecal microbial richness and emergence of virulence factors were observed at the mid phase of CRC induction. Mouse colonic mucosal tissues were collected before (day 0) and on various days after administration of AOM/DSS (i.e., day 46 as early phase, day 56 as mid phase, and day 66 as late phase), and were analyzed using microarray. Unique profiles of autophagy-related genes were identified in the colonic mucosa during the mid phase, which correlated with the presence of intraepithelial bacteria.