Project description:To identify potential unique miRs that contribute to shaping the intestinal stemness in colitis, we analyzed the miRNome of colonic crypt stem cells from DSS-induced colitis mice.
Project description:Inflammation dramatically alters the gut microenvironment. To investigate the transcriptome changes the temporal profile of multiple signaling pathways throughout the progression of colitis, we collected the colonic tissue at a series of time points during DSS colitis for bulk RNA sequencing.
Project description:The microenvironment of injured mucosa has important effects on intestinal stem cell self-renewal and reconstruction of epithelial barrier function in inflammatory bowel disease (IBD). However, the precise status of the interactions between intestinal epithelial cell (IEC) injury, particularly intestinal crypt absence, and microenvironment in IBD is not completely understood. We identified miR-494-3p as important for protection of colonic stemness in intestinal inflammation colonic organoid culture. A novel cytokine-cytokine receptor, EDA-A2/EDA2R, could suppress colonic stemness and epithelial repair during IBD. During intestinal inflammation, high level of LP macrophage-derived EDA-A2 inhibited the nuclear β-catenin/c-Myc axis and organoid growth by targeting EDA2R in colonic crypt stem cells. We further demonstrated that the pro-inflammatory cytokines IL-1β and IL-6 are capable of stimulating macrophages to release EDA-A2 during colitis. Secondly, we identified the cross-talk among IECs, colonic crypts, and lamina propria (LP) macrophages in miR-494-3p-mediated colitis. Furthermore, our study showed that miR-494-3p deficiency in IECs promoted LP macrophage recruitment and M1 activation in DSS-induced colitis mice. In addition, we identified miR-494-3p as critical to dampening IEC injury; specifically, miR-494-3p inhibited inflammation-induced IKKβ/NF-κB activation by targeting the IKKβ 3’UTR in IECs. As such, administration of adequate amounts of a miR-494-3p agomire attenuate colitis in vivo. Consistent with this inference, we showed that miR-494-3p levels were decreased in colonic crypts and serum in colitis mice, and loss of miR-494 potentiated the severity of colonic colitis. Our clinical data on the interactions between miR-494-3p levels in serum exosomes & colonic tissues and associated outcomes support the clinical relevance of miR-494-3p in IBD. The miR-494-3p agomir system, which we designed permits local delivery in vivo in this study, significantly ameliorated the severity of colonic colitis. Our findings no only uncover a miR-494-3p-mediated cross-talk mechanism by which inflamed colonic LP macrophages integrate signals from IECs to regulate colonic stemness and colonic epithelial repair/homeostasis. The miR-494-3p agomir may serve as a potential therapeutic approach in IBD.
Project description:The lack of suitable animal models reflecting chronically relapsing inflammation and tissue remodeling have hindered fibrosis research in inflammatory bowel diseases (IBD). This study investigated changes in connective tissue in a chronic murine model using different cycles of dextran sodium sulphate (DSS) to mimic the relapsing nature of the disease. We used whole gene expression arrays to study differences in colonic gene expression levels between acute and more chronic DSS colitis, Acute and chronic relapsing colonic inflammation was induced in C57BL6 female mice using several cycles of exposure to DSS in drinking water, followed by recovery phases. Total RNA, extracted from snap frozen colon from five mice per condition was used to analyze mRNA expression via Affymetrix Mouse Gene 1.0 ST arrays.
Project description:The lack of suitable animal models reflecting chronically relapsing inflammation and tissue remodeling have hindered fibrosis research in inflammatory bowel diseases (IBD). This study investigated changes in connective tissue in a chronic murine model using different cycles of dextran sodium sulphate (DSS) to mimic the relapsing nature of the disease. We used whole gene expression arrays to study differences in colonic gene expression levels between acute and more chronic DSS colitis,
Project description:We compared the transcriptional signatures of the colonic mucosa from control mice (WT) versus mice deficient for the epithelial pantetheinase Vnn1 (Vnn1KO) or overexpressing Vnn1 specifically in intestinal epithelial cells (VIVA transgenic mice), during the development of DSS-induced colitis.
Project description:Inflammation markedly alters the microenvironment of intestinal tissue. To explore alterations in the cell composition and transcription of intestinal tissue during colitis, we conducted single-cell RNA sequencing analysis of the colonic tissues obtained from the mice treated with 3% DSS for 6 days.
Project description:TMT proteomics for colonic mucosa in DSS-induced colitis mice with or without administrated Cyanidin-3-O-glucoside was used for discovery of differential expressed proteins.
Project description:Colonic epithelial repair is a key determinant of health. After injury, repair initiates through phenotypic reprogramming of wounded epithelium to a regenerative state permissive for the activation of alternative stem cell populations and healing. Although cytokine signals such as interferons may help induce regenerative reprogramming, the signals that modify this state as the wound resolves remain largely unknown. Here we examined whether cytokine signaling mediated by tumor necrosis factor receptor 2 (TNFR2) influenced the wound repair process. We examined mice with targeted deletion of the Tnfrsf1b (TNFR2) gene in intestinal/colonic epithelium (Vil1::Cre;Tnfr2-f/f) and compared their transcriptional profiles to control (Tnfr2-f/f) mice. We sorted EpCAM+ (epithelial) cells from Vil1::Cre;Tnfr2-f/f and control DSS-treated mice and performed bulk RNA-Seq. Comparison of transcript expression profile before and after DSS-induced colitis in control (Tnfr2-f/f) mice revealed upregulation of pathways associated with metabolic regulation, ribosomal function, oxidative stress, TNF signaling, and focal adhesions after DSS treatment. Pathway enrichment analysis demonstrated elevated regenerative (“fetal”) intestinal signaling, reduced inflammation, and increased proliferative signaling in Vil1::Cre;Tnfr2-f/f colonic epithelium after DSS treatment. The knockout epithelium also showed reduced expression of markers of differentiated colonic epithelium and elevated expression of progenitor cell signaling. Thus, the transcriptional data were consistent with increased regenerative signaling in TNFR2-knockout epithelium, suggesting that TNFR2 has a role in restraining the relatively undifferentiated regenerative state.