ABSTRACT: Gene expression analysis of FACS-isolated mammary stromal cells (Fsp1-expressing) between stromal Gli2 wild type control and stromal Gli2 ablated mice
Project description:The capacity of stem cells to maintain and regenerate organs is critically dependent on the niche, a complex signaling microenvironment that sustains and regulates stem cell activity. Niche function in the mammary gland must integrate local homeostatic activities with hormonally regulated events, such as pregnancy or the onset of puberty. In the human disorder CPHD (combined pituitary hormone deficiency) breast growth defects at puberty are associated with mutations disrupting the transcription factor, GLI2. Here we find that Gli2 functions in mouse mammary stromal cells to shape a niche signaling program that sustains mammary epithelial stem cells. Ablation of Gli2 in stromal cells thus leads to a disorganized mammary gland, associated with collapse of the niche signaling environment, with a five-fold decrease in functional mammary stem cell activity, and with attenuated response to the mammatrophic hormones estrogen and growth hormone. Consistent with a niche defect, aspects of Gli2-deficient mammary gland architecture can be rescued by local supplementation with IGF and WNT protein signals. Our findings thus identify GLI2 as a critical coordinator of local and hormonal influences on the niche signaling program, and suggest that mammary pathogenesis in CPHD patients results from dysfunction of the mammary epithelial stem cell niche. We used microarrays to identify gene expression signatures associated with stromal Gli2 expression
Project description:Germline mutations in LKB1 predispose to hereditary Peutz-Jeghers Syndrome (PJS), manifesting with gastrointestinal polyposis. We discovered that conditional deletion of Lkb1 in stromal fibroblasts using Fsp1-Cre leads to expansion of stromal cells and gastrointestinal polyposis in mice. Here we have investigated gene expression signatures in the Fsp1-Cre;Lkb1fl/fl mouse polyps harbouring bi-allelic deletion of Lkb1 in stromal cells together with wild-type epithelium. We provide RNA-seq gene expression data of 6 polyps, 4 adjacent gastric mucosa samples and 5 wild-type gastric mucosa samples from littermate controls. Our experiment demonstrates e.g. activated cytokine signaling and inflammatory pathways in the polyps.
Project description:A single-cell transcriptional analysis was performed on GLI2+ stromal cells from the adult murine lung. Whole adult murine lung tissue was dissociated to single cells and subjected to fluorescence activated cell sorting (FACS) to select all live GLI2+ cells. The single cell RNA-sequencing library was then subsequently generated. Cells were sequenced at a depth of ~60,000 reads/cell. We captured approximately 4,600 cells with a median of 2,246 genes detected per cell utilizing a droplet-based barcoding approach to capture single cells for RNA sequencing. The results demonstrate that the GLI2+ population is segregated into distinct stromal subtypes along the proximal-distal axis of the lung with distinct functional contribution to matrix production and paracrine signaling within their distinctive niche.
Project description:Fibroblasts are present in every organ. While the role fibroblasts in chronic diseases such as fibrosis or tumor expression has been extensively explored, little is known about their physiological role. The kidney possesses a unique capacity to recover from even severe acute injury. We study molecular mechanisms of this intrinsic repair capacity in the mouse model of ischemia-reperfusion (IR). In this model, the renal artery and vein are clamped for 45 min, leading to acute kidney injury. The kidney spontaneously recovers from such IR injury within 14 days. IR kidney injury is associated with a transient accumulation of fibroblasts in the diseased tissue. We hypothesized that fibroblasts aid the repair of acute IR injury in the kidney. To elucidate how FSP1+ fibroblasts may contribute to the repair of kidney injury, we undertook a global unbiased approach to compare gene expression profiles of fibroblasts isolated from kidneys post-IRI and from control kidneys by FACS sorting. To investigate the role fibroblasts may play in the repair of kidney inhury, we performed ischemia reperfusion injury surgery on transgenic mice in which the FSP-1 promoter drives EGFP expression. Kidney injury peaks at day 3 post-IRI, followed by spontaneous regeration that restores nearly perfect kidney architecture and health by day 10. Fibroblasts are thought to possibly play a role in this process, as they are normally rare in the healthy kidney, acute kidney injury is associated with a transient accumulation of interstitial fibroblasts, but whether they may help repair the acute kidney injury or in fact could contribute to the damage is not known. To compare the gene expression profiles of normal fibroblasts and those from post-ischemic kidneys, we sacrificed control FSP1-GFP mice and the FSP1-GFP mice three days post-IRI. We generated single-cell suspensions from both the post-IRI and control kidneys, and then isolated FSP1-GFP+ cells by FACS sorting that, when cultured on plastic, displayed typical fibroblast morphology. Total RNA was immediately extracted from the sorted cells and amplified to produce enough for a array. We biotinylated five of the samples from post-ischemic kidneys and three of the control (non-ischemic) kidneys and used Affymetrix 3' Arrays to examine differences in gene expression profiles between the two groups that may she some light on what role, if any, fibroblasts play in the spontaneous healing of the kidney after acute kidney injury. We performed ischemia reperfusion surgery in FSP1-GFP mice, and at day 3, we sacrificed the mice, isolated FSP1-GFP positive cells from both IR and normal control kidneys by FACS sorting, extracted total RNA from the isolated FSP1-GFP cells and used Affymetrix Mouse Expression Array 430 2.0 microarrays to perform gene expression profiling of the samples. All told, we performed the FACS Sorting, RNA extration, and hybridization with 5 ischemic kidneys and 3 normal kidneys. Fibroblasts, acute kidney injury, repair, comparative gene expression profiling, microarrays, FACS sorting, role in healing
Project description:We demonstrate the conserved Hh-GLI2-mediated chromatin and transcriptional regulation of both stomach and intestinal stromal stem cell niche signals. Analyses of H3K27ac marks demonstrate GLI2-mediated transcription regulation of stem cell niche signals such as Wnt ligand genes, through enhancers conserved between the stomach and intestine.
Project description:We demonstrate the conserved Hh-GLI2-mediated chromatin and transcriptional regulation of both stomach and intestinal stromal stem cell niche signals. Analyses of H3K27ac marks demonstrate GLI2-mediated transcription regulation of stem cell niche signals such as Wnt ligand genes, through enhancers conserved between the stomach and intestine.
Project description:A comparative single cell transcriptional analysis of murine CXCL12-abundant reticular stromal cells isolated from ablated and control bone marrow