Project description:Nutritional and genetic risk factors for intestinal tumors are additive on mouse tumor phenotypes, demonstrating that diet and genetic factors impact risk by distinct combinatorial mechanisms. We analyzed expression profiles of small intestine crypts and villi from mice with nutritional and genetic risk factors. The results advanced our understanding of the mechanistic roles played by major risk factors in the pathogenesis of intestinal tumors. Small intestine crypts and villi from mice with nutritional (Ain76A, NWD1, and NWD2) and genetic risk factors (WT, Apc1638N/+ and p21-/-) were collected for RNA extraction and analysis using the Affymetrix 3' IVT expression microarray. Three or four replicates per tissue/risk factor.
Project description:Nutritional and genetic risk factors for intestinal tumors are additive on mouse tumor phenotypes, demonstrating that diet and genetic factors impact risk by distinct combinatorial mechanisms. We analyzed expression profiles of small intestine crypts and villi from mice with nutritional and genetic risk factors. The results advanced our understanding of the mechanistic roles played by major risk factors in the pathogenesis of intestinal tumors.
Project description:Alcohol induced damages to teh crypts and villi of mouse small intestine revealed by laser capture microdissection (LCM)-based sample collection, DIA-based untargeted proteomics
Project description:Background & Aims: We have recently established long-term culture conditions under which single crypts or stem cells derived from murine small intestine expand over long periods of time. Growing crypts undergo multiple crypt fission events, whilst simultaneously generating villus-like epithelial domains in which all differentiated cell types are present. We have now adapted the culture conditions to grow similar epithelial organoids from mouse colon and human small intestine and colon. Methods: Based on the murine small intestinal culture system, we optimized the murine and human colon culture system. Results: Addition of Wnt3A to the growth factor cocktail allowed mouse colon crypts to expand indefinitely. Further addition of nicotinamide, a small molecule Alk inhibitor and a p38 inhibitor was essential for long-term human small intestine and colon culture. The culture system also allowed growth of murine Apcmin adenomas, human colorectal cancer and human esophageal metaplastic Barrett’s epithelium. Conclusion: The culture technology should be widely applicable as a research tool for infectious, inflammatory and neoplastic pathologies of the human gastrointestinal tract. Moreover, regenerative applications may become feasible with ex vivo expanded intestinal epithelia. Human organoids were grown embedded in Matrigel in HISC (Human intestinal stem cell culture) medium. Additionally, human small intestinal crypts and villi were isolated independently from a freshly operated sample. RNA was isolated using the RNeasy Micro kit (Qiagen). Samples were labled according to Agilent guidelines with Cy3, whereas human reference RNA (Stratagene) was labeled in Cy5. Feature Extraction Software was used to extract and normalize data.
Project description:To investigate the impact transcription that the Spore Forming (SF) Community of bacteria have on the small intestine, B6 mice on a autoclaved diet that were germfree (GF) or colonized with the SF community were investigated. Using laser capture microdissection the intestinal epithelial cells on the villi and the crypts were dissected out and bulk RNA seq was performed.
Project description:Paneth cells are antimicrobial peptide-secreting cells located at the base of the crypts of the small intestine. The proteome of Paneth cells is not well defined because of their co-existence with stem cells making it difficult to culture Panth cells alone in vitro. Using a simplied toluidine blue O method for staining mouse intestinal tissue, laser capture microdissection (LCM) to isolate cells from the crypt region and surfactant assisted one pot protein digestion, we identified more than 1,300 proteins from crypts equivalent to 18,000 cells. Compared with the proteomes of villi and smooth muscle regions, the crypt proteome is highly enriched in defensins, lysozymes and other antimicrobial peptides that are characteristic of Paneth cells. The sensitivity of the LCM-based proteomics approach was also assessed using a smaller number of cell equivalent tissues, a comparable proteomic coverage can be achieved with 3,600 cells. This work is the first proteomics study of intestinal tissue enriched with Paneth cells. The simplied workflow enables profiling of Paneth cell associated pathological changes at the proteome level directly from frozen intestinal tissue. It may also be useful for proteomics studies of other spatially resolved cell types from other tissues.
Project description:Differentiation and specialisation of epithelial cells in the small intestine is regulated in two ways. First, there is differentiation along the crypt-villus axis of the intestinal stem cells into absorptive enterocytes, Paneth, goblet, tuft, enteroendocrine or M-cells, which is mainly regulated by WNT. Second, there is specialization along the cephalocaudal axis with different absorptive and digestive functions in duodenum, jejunum and ileum that is controlled by several transcription factors such as GATA4. However, so far it is unknown whether location-specific functional properties are intrinsically programmed within stem cells or if continuous signalling from mesenchymal cells is necessary to maintain the location-specific identity of the small intestine. By using the pure epithelial organoid technique, we show that region-specific gene expression profiles are conserved throughout long-term cultures of both mouse and human intestinal stem cells and correlated with differential Gata4 expression. Furthermore, the human organoid culture system demonstrates that Gata4-regulated gene expression is only allowed in absence of WNT signalling. These data show that location-specific function is intrinsically programmed in the adult stem cells of the small intestine and that their differentiation fate is independent of location-specific extracellular signals. In light of the potential future clinical application of small intestine-derived organoids, our data imply that it is important to generate GATA4-positive and GATA4-negative cultures to regenerate all essential functions of the small intestine. RNA sequencing of intestinal crypts, villi and cultured organoids derived from mouse duodenum, jejunum and ileum
Project description:DIGE results of mouse models of colon cancer. Tissue harvested from small intestines of Apc1638N+/- and p21-/- mice as per the method developed by Wieser et al. (1973). Spots identified as significant (alpha<0.05) in the comparison of mutant mouse crypts and villi to WT crypts and villi, respectively.
Project description:Rb and E2F are thought to play antagonistic roles in celll proliferation. However, this model is based mostly from in vitro cell culture systems. We used small intestines to test this model in vivo. We found that deletion of E2f1-3 in the small intestine of mice suppressed the ectopic expression of E2F targets and cell proliferation caused by Rb-deficiency. Surprisingly, E2f1-3 deletion failed to arrest the proliferation of intestinal cells containing an intact Rb gene, and instead led to E2F target derepression and apoptosis. Experiment Overall Design: Total RNA of crypts and villi from wild-type, Rb-/-, E2f1-/-, E2f2-/-, E2f3-/-, E2f1-/-, E2f2-/-, and E2f3-/- small intestines. Small intestines were harvested 7 days after mice were injected intraperitoneally with beta-napthoflavone.
Project description:The small intestinal epithelium is the most rapidly self-renewing tissue of mammals. Proliferative cells are confined to crypts, while differentiated cell types predominantly occupy the villi. We recently demonstrated the existence of a long-lived pool of cycling stem cells defined by Lgr5 expression and intermingled with post-mitotic Paneth cells at crypt bottoms. We have now determined a gene signature for these so called Crypt Base Columnar (CBC) cells. One of the genes within this stem cell signature is the Wnt target Ascl2. Transgenic expression of the Ascl2 transcription factor throughout the intestinal epithelium induces crypt hyperplasia and de novo crypt formation on villi. Induced deletion of the Ascl2 gene in adult small intestine leads to disappearance of the CBC stem cells within days. The combined results from these gain- and loss-of-function experiments imply that Ascl2 controls intestinal stem cell fate. Keywords: expression profiling