Project description:Intestinal epithelial stem cells (ISCs) are the focus of recent intense study. Current in vitro models rely on supplementation with the Wnt agonist R-spondin1 to support robust growth, ISC self-renewal, and differentiation. Intestinal subepithelial myofibroblasts (ISEMFs) are important supportive cells within the ISC niche. We hypothesized that co-culture with ISEMF enhances the growth of ISCs in vitro and allows for their successful in vivo implantation and engraftment. ISC-containing small intestinal crypts, FACS-sorted single ISCs, and ISEMFs were procured from C57BL/6 mice. Crypts and single ISCs were grown in vitro into enteroids, in the presence or absence of ISEMFs. ISEMFs enhanced the growth of intestinal epithelium in vitro in a proximity-dependent fashion, with co-cultures giving rise to larger enteroids than monocultures. Co-culture of ISCs with supportive ISEMFs relinquished the requirement of exogenous R-spondin1 to sustain long-term growth and differentiation of ISCs. Mono- and co-cultures were implanted subcutaneously in syngeneic mice. Co-culture with ISEMFs proved necessary for successful in vivo engraftment and proliferation of enteroids; implants without ISEMFs did not survive. ISEMF whole transcriptome sequencing and qPCR demonstrated high expression of specific R-spondins, well-described Wnt agonists that supports ISC growth. Specific non-supportive ISEMF populations had reduced expression of R-spondins. The addition of ISEMFs in intestinal epithelial culture therefore recapitulates a critical element of the intestinal stem cell niche and allows for its experimental interrogation and biodesign-driven manipulation. Two samples of intestinal subepithelial myofibroblasts were used in this study.
Project description:Intestinal epithelial stem cells (ISCs) are the focus of recent intense study. Current in vitro models rely on supplementation with the Wnt agonist R-spondin1 to support robust growth, ISC self-renewal, and differentiation. Intestinal subepithelial myofibroblasts (ISEMFs) are important supportive cells within the ISC niche. We hypothesized that co-culture with ISEMF enhances the growth of ISCs in vitro and allows for their successful in vivo implantation and engraftment. ISC-containing small intestinal crypts, FACS-sorted single ISCs, and ISEMFs were procured from C57BL/6 mice. Crypts and single ISCs were grown in vitro into enteroids, in the presence or absence of ISEMFs. ISEMFs enhanced the growth of intestinal epithelium in vitro in a proximity-dependent fashion, with co-cultures giving rise to larger enteroids than monocultures. Co-culture of ISCs with supportive ISEMFs relinquished the requirement of exogenous R-spondin1 to sustain long-term growth and differentiation of ISCs. Mono- and co-cultures were implanted subcutaneously in syngeneic mice. Co-culture with ISEMFs proved necessary for successful in vivo engraftment and proliferation of enteroids; implants without ISEMFs did not survive. ISEMF whole transcriptome sequencing and qPCR demonstrated high expression of specific R-spondins, well-described Wnt agonists that supports ISC growth. Specific non-supportive ISEMF populations had reduced expression of R-spondins. The addition of ISEMFs in intestinal epithelial culture therefore recapitulates a critical element of the intestinal stem cell niche and allows for its experimental interrogation and biodesign-driven manipulation.
Project description:PDGFRA-expressing mesenchyme supports intestinal stem cells. Stomach epithelia have related niche dependencies, but their enabling mesenchymal cell populations are unknown, in part because previous studies pooled the gastric antrum and corpus. Our high-resolution imaging, transcriptional profiling, and organoid assays identified regional subpopulations and supportive capacities of purified mouse corpus and antral PDGFRA+ cells. Sub-epithelial PDGFRAHi myofibroblasts are principal sources of BMP ligands and two molecularly distinct pools distribute asymmetrically along antral glands but together fail to support epithelial growth in vitro. In contrast, PDGFRALo CD55+ cells strategically positioned beneath gastric glands promote epithelial expansion in the absence of other cells or factors. This population encompasses a small fraction expressing the BMP antagonist Grem1. Although Grem1+ cell ablation in vivo impairs intestinal stem cells, gastric stem cells are spared, implying that CD55+ cell activity in epithelial self-renewal derives from other subpopulations. Our findings shed light on spatial, molecular, and functional organization of gastric mesenchyme and the spectrum of signaling sources for epithelial support.
Project description:Adjacent stroma, including subepithelial fibroblasts, are believed to coordinate the differentiation process of epithelial cells, but the mechanisms are not well understood. Glial cell line-derived neurotrophic factor (GDNF) is expressed in the intestinal Pdgfra high subepithelial myofibroblasts (SEMFs), while the GDNF receptor RET is expressed in a subset of enteroendocrine cells (EECs), indicating regulatory crosstalk. In this experiment, single RET+ intestinal cells were sorted the gene expression profile was compared to non-RET cells. This provided knowledge about RET+ cell types. RET+ cells were upregulated with most of the EEC markers, indicating that RET+ cells are expressed in EECs. We also observed the differences in the gene expression profile of stromal-derived GDNF ligand on intestinal organoids. Organoids were derived from intestinal crypts of WT mice C57BL/6J and treated with 500ng/ml of Gdnf and Gfra1. GDNF-treated organoids induced the expression of EEC genes such as Pyy, Tac1, Tph1, and Cck, indicating enhanced differentiation of EC cell and L-I-N cell lineages. This highlights a stroma-epithelium crosstalk pathway regulating the differentiation of intestinal EEC subtypes.
Project description:Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by non-epithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin (IL)-33 as an epithelial cell-derived regulator of stromal cell activation and mediator of intestinal polyposis. IL-33 expression was elevated in the tumors and serum of colorectal cancer patients and induced in the adenomatous polyps of ApcMin/+ mutant mice. Genetic and antibody suppression of IL-33 signaling in ApcMin/+ mice inhibited proliferation, induced apoptosis, and suppressed angiogenesis in polyps, which reduced both tumor number and size. In ApcMin/+ polyps, IL-33 expression localized to tumor epithelial cells and expression of the IL-33 receptor, IL1RL1, associated with two stromal cell types, namely subepithelial myofibroblasts (SEMFs) and mast cells, whose activation was previously associated with polyposis. In vitro IL-33 stimulation of human SEMFs induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in ApcMin/+ polyps and expression of mast cell-derived proteases and cytokines known to promote polyposis. Together, our results suggest that IL-33 is a tumor epithelial cell-derived paracrine signal that promotes polyposis through the coordinated activation of stromal cells and the formation of a reactive stroma microenvironment. Six T-75 flasks of CCD-18Co cells were grown to 80% confluency; three were treated with rhIL-33, three were given vehicle control; cells were trypsinized and split in two--half of each flask used for sequencing and half for qPCR validation post-sequencing
Project description:We isolated myofibroblasts from C57BL6/J mouse ileum or colon and analyzed gene expression profiles from the cultured cells. We also isolated human colon cancer cells from xenografts interacting with mouse intestinal subepithelial myofibroblasts (ISEMFs) and analyzed gene expression in sorted human cancer cells. We used Affymetrix microarrays to detail the global gene expression prolfiles in mouse fibroblasts and human colon cancer cells and identified distinct biological processes of differentially expressed genes in mouse fibroblasts and interacting human colon cancer cells For mouse SEMFs, we isolated fresh fibroblasts from mouse ileum and colon, confirmed their predicted immunophenotype (alpha SMA positive, vimentin positive, desmin negative), and expanded cells in culture before expression array analysis. We examined gene expression in human cancer cells following their interaction with murine ileal or colonic SEMFs, using flow cytometry to isolate DsRed-expressing Caco2 or T84 cells after 5 weeks of growth in NOD/SCID mice in the presence of GFP-expressing ileal or colonic SEMFs.
Project description:In a series of mouse genetic studies, we concluded that miR-143/145 expression in intestinal subepithelial myofibroblasts (ISEMFs) promotes epithelial regeneration after DSS-mediated injury in the colon. This experiment aims to identify miR-143/145 target genes that are involved in this function. We generated primary ISEMFs from wildtype and miR-143/145 null mouse colons and analyzed their gene expression profile. We further subjected ISEMFs to LPS treatment, in order to measure gene expression changes that are only revealed after inflammatory stress. Three wild-type and three miR-143/145 null ISEMF cell lines were isolated from mouse colons. Cells were treated with or without 1 ug/mL LPS for 24 hours and total RNA was isolated. Gene expression was profiled using Illumina microarrays.
Project description:We isolated myofibroblasts from C57BL6/J mouse ileum or colon and analyzed gene expression profiles from the cultured cells. We also isolated human colon cancer cells from xenografts interacting with mouse intestinal subepithelial myofibroblasts (ISEMFs) and analyzed gene expression in sorted human cancer cells. We used Affymetrix microarrays to detail the global gene expression prolfiles in mouse fibroblasts and human colon cancer cells and identified distinct biological processes of differentially expressed genes in mouse fibroblasts and interacting human colon cancer cells
Project description:Wnt/b-catenin signaling supports intestinal homeostasis by regulating proliferation in the crypt. Multiple Wnts are expressed in Paneth as well as other intestinal epithelial and stromal cells. Ex vivo, Wnts secreted by Paneth cells can support intestinal stem cells when Wnt signaling is enhanced with supplemental R-Spondin 1 (RSPO1). However, in vivo, the source of Wnts in the stem cell niche is less clear. Genetic ablation of Porcn, an endoplasmic reticulum resident O-acyltransferase that is essential for the secretion and activity of all vertebrate Wnts, confirmed the role of intestinal epithelial Wnts in ex vivo culture. Unexpectedly, mice lacking epithelial Wnt activity (PorcnDel/Villin-Cre mice) had normal intestinal proliferation and differentiation, as well as successful regeneration after radiation injury, indicating epithelial Wnts are dispensable for these processes. Consistent with a key role for stroma in the crypt niche, intestinal stromal cells endogenously expressing Wnts and Rspo3 support the growth of PorcnDel organoids ex vivo without RSPO1 supplementation. Conversely, increasing pharmacologic PORCN inhibition, affecting both stroma and epithelium, reduced Lgr5 intestinal stem cells, inhibited recovery from radiation injury, and at the highest dose fully blocked intestinal proliferation. We conclude that epithelial Wnts are dispensable, and that stromal production of Wnts can fully support normal murine intestinal homeostasis. Microarray was performed on samples enriched for stromal or epithelial cells from small intestine from Porcn(Del)/Villin-Cre and Porcn(WT)/Villin-Cre male C57Bl/6 mice.
Project description:Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by non-epithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin (IL)-33 as an epithelial cell-derived regulator of stromal cell activation and mediator of intestinal polyposis. IL-33 expression was elevated in the tumors and serum of colorectal cancer patients and induced in the adenomatous polyps of ApcMin/+ mutant mice. Genetic and antibody suppression of IL-33 signaling in ApcMin/+ mice inhibited proliferation, induced apoptosis, and suppressed angiogenesis in polyps, which reduced both tumor number and size. In ApcMin/+ polyps, IL-33 expression localized to tumor epithelial cells and expression of the IL-33 receptor, IL1RL1, associated with two stromal cell types, namely subepithelial myofibroblasts (SEMFs) and mast cells, whose activation was previously associated with polyposis. In vitro IL-33 stimulation of human SEMFs induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in ApcMin/+ polyps and expression of mast cell-derived proteases and cytokines known to promote polyposis. Together, our results suggest that IL-33 is a tumor epithelial cell-derived paracrine signal that promotes polyposis through the coordinated activation of stromal cells and the formation of a reactive stroma microenvironment.