Project description:Five colorectal adenocarcinomas and matched normal colonic tissues were analyzed with Affymetrix HG-U133-Plus-2.0 microarrays. Two labs independently generated microarray data with the same array platform on the same biological samples.
Project description:Based on genetic risk factors and natural history, Crohn’s disease (CD) can be separated in two entities, an ileal and a colonic disease. Protein based-approaches are needed to elucidate whether such subphenotypes are related to distinct pathophysiological processes. In this work, we compared the proteome of ulcer edge to the one of paired control tissue in ileum and colon of CD patients. We revealed that ileal and colonic ulcer edge can be distinguished by a differential distribution of epithelial–mesenchymal transition proteins, neutrophil degranulation proteins and ribosomal proteins. In ileal and colonic ulcer edge, we found a quasi-systematic increase of the proteins implicated in the pathway of protein processing in endoplasmic reticulum and a quasi-systematic decrease of mitochondrial proteins. Our study provides for the first time protein-based evidences showing partly distinct pathophysiological processes associated to ileal and colonic ulcer edge in CD. This could constitute a first step toward the development of gut segment-specific diagnostic markers and therapeutics.
Project description:There is a gradient of M-NM-2-catenin expression along the colonic crypt axis with the highest levels at the crypt bottom. However, it remains unclear whether different levels of canonical Wnt signaling exert distinct roles in the colonic epithelium. In the present study, we first showed that the canonical Wnt signaling is active in the proliferative compartment of normal colonic crypts by separating actively proliferating progenitor cells from non-proliferating cells in the colon using transgenic mice expressing a histone H2B-green fluorescent protein (GFP) fusion protein under the control of a tetracycline responsive regulatory element. Subsequently, we investigated the dose-dependent effect of canonical Wnt activation on colonic epithelial differentiation by controlling the expression levels of stabilized M-NM-2-catenin using a doxycycline-inducible transgenic system in mice. We show that elevated levels of Wnt signaling induce the amplification of Lgr5+ cells, which is accompanied by crypt fission and a reduction in cell proliferation among progenitor cells. In contrast, lower levels of M-NM-2-catenin induction enhanced cell proliferation rates of epithelial progenitors without affecting crypt fission rates. Notably, slow-cycling cells produced by M-NM-2-catenin activation exhibit activation of Notch signaling and the treatment of M-NM-2-catenin expressing mice with a Notch inhibitor turned such slow-cycling cells into actively proliferating cells. Our results indicate that the activation of the canonical Wnt signaling pathway is sufficient for de novo crypt formation, and suggest that different levels of canonical Wnt activations, in cooperation with Notch signaling, establish a hierarchy of slower-cycling stem cells and faster-cycling progenitor cells characteristic for the colonic epithelium. To separate actively proliferating cells from non-proliferating cells in normal colon, we used transgenic mice expressing a histone H2B-GFP fusion protein under the control of a tetracycline responsive regulatory element (H2B-GFP mice). In H2B-GFP mice, all colonic crypt cells exhibited strong nuclear GFP signal 7 days after doxycycline administration. When doxycycline was withdrawn for 2 days after the labeling period, nuclear GFP signal was diluted in proliferating cells whereas non-proliferating cells retained GFP. GFPhigh non-proliferating and GFPlow proliferating epithelial cells were sorted from the isolated crypts by FACS for microarray analysis. In addition, to investigate the effects of acute Wnt activation in colon, we generated doxycycline-inducible M-NM-2-catenin mice. Colonic crypts were isolated from untreated mice and mice fed doxycycline in the drinking water (2.0 mg/ml) for 5 days and subjected to microarray analysis.
Project description:There is a gradient of β-catenin expression along the colonic crypt axis with the highest levels at the crypt bottom. However, it remains unclear whether different levels of canonical Wnt signaling exert distinct roles in the colonic epithelium. In the present study, we first showed that the canonical Wnt signaling is active in the proliferative compartment of normal colonic crypts by separating actively proliferating progenitor cells from non-proliferating cells in the colon using transgenic mice expressing a histone H2B-green fluorescent protein (GFP) fusion protein under the control of a tetracycline responsive regulatory element. Subsequently, we investigated the dose-dependent effect of canonical Wnt activation on colonic epithelial differentiation by controlling the expression levels of stabilized β-catenin using a doxycycline-inducible transgenic system in mice. We show that elevated levels of Wnt signaling induce the amplification of Lgr5+ cells, which is accompanied by crypt fission and a reduction in cell proliferation among progenitor cells. In contrast, lower levels of β-catenin induction enhanced cell proliferation rates of epithelial progenitors without affecting crypt fission rates. Notably, slow-cycling cells produced by β-catenin activation exhibit activation of Notch signaling and the treatment of β-catenin expressing mice with a Notch inhibitor turned such slow-cycling cells into actively proliferating cells. Our results indicate that the activation of the canonical Wnt signaling pathway is sufficient for de novo crypt formation, and suggest that different levels of canonical Wnt activations, in cooperation with Notch signaling, establish a hierarchy of slower-cycling stem cells and faster-cycling progenitor cells characteristic for the colonic epithelium.
Project description:During ontogeny, γδ T cells emerge from the thymus and directly seed peripheral tissues for in situ immunity, though their functional role in humans is largely defined from blood. Here, we analyzed the phenotype, transcriptome, function, and repertoire of human γδ T cells in blood, mucosal and lymphoid tissues from 176 donors across the lifespan, revealing distinct profiles in children compared to adults. In early life, clonally diverse Vd1 subsets predominate across blood and tissues, comprising naïve and differentiated effector and tissue repair functions, while cytolytic Vd2 subsets populate blood, spleen and lungs. Over age, both subsets exhibit clonal expansions disseminated across sites and express elevated cytolytic signatures. In adults, Vd2 cells predominate in blood, while Vd1 cells are enriched across tissues and express residency profiles. These results indicate that antigenic exposures over childhood drive the functional evolution and tissue compartmentalization of γδ T cells, leading to age-dependent roles in immunity.
Project description:Five colorectal adenocarcinomas and matched normal colonic tissues were analyzed with Affymetrix HG-U133-Plus-2.0 microarrays. Two labs independently generated microarray data with the same array platform on the same biological samples. Colorectal adenocarcinomas and matched normal colonic RNA sample were purchased from Oncomatrix, Inc., San Diego, CA. The RNA from each biological sample was distributed to and processed in two laboratories at Stanford University.
Project description:The colonic lamina propria contains a distinct population of Foxp3+ T regulatory cells (Tregs) that modulate responses to commensal microbes. Analysis of gene expression revealed that the transcriptome of colonic Tregs is distinct from splenic and other tissue Tregs. Rorγ and Helios in colonic Tregs mark distinct populations: Rorγ+Helios- or Rorγ-Helios+ Tregs. We uncovered an unanticipated role for Rorγ, a transcription factor generally considered to be antagonistic to Foxp3. Rorγ in colonic Tregs accounts for a small but specific part of the colon-specific Treg signature. (1) Total colonic and splenic Foxp3+ Treg comparison: Lymphocytes were isolated from colonic lamina propria and spleens of Foxp3-ires-GFP mice, where GFP reports Foxp3 expression. TCRb+CD4+GFP+ cells were double sorted into Trizol. (2) Colonic Rorγ+ and Rorγ- Treg comparison: Foxp3-ires-Thy1.1 reporter mice were crossed to Rorc-GFP reporter mice to generate mice that report both Foxp3 and Rorγ expression. Rorγ+Foxp3+ Tregs (TCRb+CD4+Thy1.1+GFP+) and Rorγ-Foxp3+ Tregs (TCRb+CD4+Thy1.1+GFP-) from colonic lamina propria were double sorted into Trizol.To reduce variability and increase cell number, cells from multiple mice were pooled for sorting and at least three replicates were generated for all groups. RNA from 1.5-3.0 x104 cells was amplified, labeled and hybridized to Affymetrix Mouse Gene 1.0 ST Arrays.