Project description:Mist1+ cells and parietal cells in mouse stomach were separatedly sorted, and RNAs were isolated. Mist1 (also known as Bhlha15) is expressed in gastric chief cells and gastric stem cells in mice. However, more specific genes for each population needs to be identified to better understand the precise biology in these cell populations. In order to address cell specific gene signature, we separately sorted Mist1+ gastric chief cells and Mist1+ gastric stem cells by FACS, and performed microarray analysis. Mist1+ gastric chief cells were sorted by using Mist1-CreERT; R26-TdTomato mouse stomach, immediately after tamoxifen administration. Mist1+ gastric stem cells were sorted by chief cell-ablated Mist1-CreERT; R26-TdTomato mouse stomach, combining with Lgr5-DTR mice. Lgr5-expressing chief cells were ablated by giving DT into these mice. As a control, acid-secreting gastric parietal cell samples were used. Mice were treated with or without Lgr5-DT ablation before sorting.
Project description:Stomachs from mice +/- H. pylori infection, +/- induction of active KRAS in gastric Mist1-expressing cells, were used for gastric single-cell RNA-sequencing. Samples were obtained six and 12 weeks after infection/KRAS induction. Six samples were frozen, then thawed before sequencing (and in some cases pooled from multiple mice) and two samples were freshly prepared and never frozen before sequencing.
Project description:Background & Aims: Spasmolytic polypeptide/TFF2-expressing metaplasia (SPEM) is known to emerge following parietal cell loss and during Helicobacter pylori infection, however its role in gastric ulcer repair is unknown. Therefore, we sought to investigate if SPEM plays a role in epithelial regeneration. Methods: Acetic acid ulcers were induced in young (2-3 months) C57BL/6 mice to determine the quality of ulcer repair. Gastric tissue was collected and analyzed to determine the expression of SPEM within the regenerating epithelium. As a comparison to native tissue the expression of SPEM was also identified within cultured gastric mouse-derived organoids. Results: Wound healing in the mice coincided with the emergence of SPEM expressing CD44v within the ulcerated region. The emergence of SPEM was also observed in cultured gastric organoids. Conclusions: These data demonstrate the SPEM may play a role in epithelial regeneration. Conclusions: These data demonstrate the SPEM may play a role in epithelial regeneration. 4 samples were used for ulcerated and uninjured tissue. 1 sample was used for intact tissue and organoid-derived RNA. The 'Ulcerated' samples represent C57BL/6 mice with ulcers and the 'Uninjured' samples represent the healthy controls (for "ulcerated" samples). The "Intact stomach tissue" and "Gastric organoids" samples are other types of samples that compared separately. "Gastric organoids" in this comparison are derived from "Intact stomach tissue".
Project description:Proliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bi-directionally towards pit and base. The isthmus is therefore generally viewed as the stem cell zone. We find that the stem cell marker Troy is expressed at the gland base by a small subpopulation of chief cells. By lineage tracing using a Troy-eGFP-ires-CreERT2 allele, single marked cells are shown to generate entirely labeled gastric units over periods of months. This phenomenon accelerates upon tissue damage. Troy+ chief cells can be cultured to generate long-lived gastric organoids. Troy marks a specific, 'plastic' subset of differentiated chief cells capable of replenishing entire gastric units, essentially serving as a quiescent ‘reserve’ stem cell. An EGFP-ires-CreERT2 cassette was introduced into the transcriptional start side of Tnfrsf19 (Troy), resulting in the expression of EGFP and CreERT2 under the control of endogenous Troy-regulatory sequences. Troy is expressed in basally located chief and parietal cells. Using FACS, Troy positive chief and parietal cells can be isolated separately. Expression profiling was performed on these two cell types: three arrays of sorted chief cells, two arrays of sorted parietal cells. As a reference, two arrays of separately isolated whole gastric corpus glands were added. In addition, single sorted Troy positive chief cells can be placed in culture, forming 3D cultures called organoids. Three arrays were generated from different organoid cultures, one time in normal medium containing the factors EGF, Gastrin, FGF10, Noggin, Wnt3a and Rspondin (EGFNWR medium) and one time in medium containing only EGF and Rspondin (ER medium).
Project description:MIST1 is a bHLH transcription factor that is necessary for the maturation of gastric zymogenic cells as they differentiate from their precursor mucous neck cells. In this experiment, mucous neck cells and zymogenic cells of normal, adult C57BL/6 and MIST1 knockout mice were laser-capture microdissected in order to determine MIST1-dependent, zymogenic cell specific gene expression.
Project description:The transcription factor MIST1 is required for final maturation of secretory cells of diverse tissues, including gastric digestive-enzyme secreting zymogenic (chief) cells (ZCs). Here, we show that MIST1 directly activates RAB26, RAB3D and several other genes. Experiment Overall Design: We used microarrays to determine genes upregulated following transient MIST1 transfection. Two gastric cell lines were used: HGC-27 and AGS. Three chips were generated from each cell line: parental (untransfected), GFP+empty vector (a control for effects of transfection), and GFP+MIST1. The latter two chips were generated from cells flow sorted based on GFP fluorescence to isolate cells with high levels of transfection. Chips were analyzed by dChip to identify genes expressed in both MIST1-transfected cell populations relative to their respective controls in multiple Boolean 'AND' comparisons.
Project description:To investigate the function of SOD1 in regulation of ISC growth, we established intestinal organoids from tamoxifen–inducible intestinal epithelial cell (IEC)–specific Sod1 knockout (Sod1f/f; Vil-creERT2) mice. We then performed gene expression profiling analysis using data obtained from RNA-seq of Sod1f/f and Sod1f/f;Vil-creERT2 organoids after 3 days of tamoxifen treatment. Organoids were derived from three mice of each genotype.
Project description:The endodermal lining of the adult gastro-intestinal tract harbors stem cells that are responsible for the day-to-day regeneration of the epithelium. Stem cells residing in the pyloric glands of the stomach and in the small intestinal crypts differ in their differentiation program and in the gene repertoire that they express. Both types of stem cells have been shown to grow from single cells into 3D structures (organoids) in vitro. We show that single adult Lgr5-positive stem cells, isolated from small intestinal organoids, require Cdx2 to maintain their intestinal identity and are converted cell-autonomously into pyloric stem cells in the absence of this transcription factor. Clonal descendants of Cdx2null small intestinal stem cells enter the gastric differentiation program instead of producing intestinal derivatives. Conversely, forced expression of Cdx2 in gastric organoids results in their intestinalization. The intestinal genetic program is thus critically dependent on the single transcription factor encoding gene Cdx2. Small intestinal crypts and stomach glands were isolated from Cdx2-/fl / Lgr5-EGFP-CreERT2 mice and cultured for a week in order to generate small intestinal (SI) and stomach (Sto) in vitro organoids. The Lgr5-CreERT2 enzyme activity has been induced by overnight 4-hydroxytamoxifen induction. Tamoxifen treated and untreated Lgr5-EGFPhi SI and Sto stem cells were FACS sorted and seeded back into ENRWfg (Sto med) culture conditions in order to generate Cdx2-/fl small intestinal (Control SI), Cdx2null small intestinal (Cdx2null SI) and Cdx2-/fl stomach (Control Sto) clonal organoids. Cdx2-/fl SI organoids and Cdx2-/fl Sto organoids have been also cultured in ENR (SI med) to induce differentiation. After some passages of clonal organoid expansion, RNA was isolated from Control SI, Cdx2null SI and Control Sto Lgr5-EGFPhi FACS sorted stem cell populations and from smal intestinal and stomach organoids cultured in different conditions and hybridized on Affymetrix Mouse Gene ST 1.1 arrays.