Project description:Epithelial gland development within the uterine lining during prepubertal period is important to ensure successful gestation in adults. Lgr5 expression in uterus becomes largely restricted to the tips of developing glands after birth. These Lgr5 highly expressing cells function as stem cells during gland development. We used microarrays to detail the gene expression profilings and compare between Lgr5 highly and negatively expressing cells in developing uterus.
Project description:We report the transcriptomic alterations of Lgr5-eGFP+ intestinal stem cells upon Wnt and R-spondin gain-of-function and loss-of-function in vivo
Project description:Lgr5+ crypt base columnar cells, the operational intestinal stem cells (ISCs), are thought to be dispensable for small intestinal (SI) homeostasis. Using a novel Lgr5-2A-DTR (Diphtheria Toxin Receptor) model which ablates Lgr5+ cells with near-complete efficiency and retains endogenous levels of Lgr5 expression, we show that persistent depletion of Lgr5+ ISCs in fact compromises SI epithelial integrity and reduces epithelial turnover in vivo. In vitro, Lgr5-2A-DTR SI organoids are unable to establish or survive when Lgr5+ ISCs are continuously eliminated when DT is in the media. However, transient exposure to DT at the start of culture allows organoids to form, and the rate of outgrowth reduces with increasing length of DT presence. Our results indicate that intestinal homeostasis requires a constant pool of Lgr5+ ISCs, which is supplied by rapidly reprogrammed non-Lgr5+ crypt populations when pre-existing Lgr5+ ISCs are ablated.
Project description:Lgr5+ cell population is the stem cell population that fuels intestinal growth in homeostatic conditions. Here, we have labeled with EGFP the Lgr5 expressing population in patient derived organoids, injected them subcutaneously in mice and disaggregated the tumors to sort the EGFP+ population and characterize its gene expression profile. This Lgr5-EGFP population is more proficient in comparison to the negative in propagating tumors both in vitro (assessed by organoid formation) and in vivo (assessed by Tumor initiation experiments)
Project description:Lgr5 positive and negative MaSC enriched P4 subpopulation were isolated from virgin Lgr5-EGFP-IRES-CreERT2 mice. The transcriptome profiles of the cells are compared to elucidate the molecular mechanism Lgr5+_MaSCs as a more defined MaSCs subpopulation within the P4 (MaSC and basal progenitor enriched popuation).
Project description:Transcriptome profiling using Affymetrix GeneChip arrays was performed on sorted populations of Lgr5-expressing mouse ovarian surface epithelium. The ovary surface epithelium (OSE) undergoes ovulatory tear-and-remodelling throughout life. Resident stem cells drive such tissue homeostasis in many adult epithelia, but their existence in the ovary has yet to be definitively proven. Lgr5 marks stem cells in multiple epithelia. Here we use reporter mice and Single Molecule Florescent-in-Situ-Hybridization (FISH) to document candidate Lgr5+ stem cells within the mouse ovary and associated structures. Lgr5 is broadly expressed during ovary organogenesis, but becomes limited to the OSE in early neonate life. In adults, Lgr5 expression is predominantly restricted to proliferative regions of the OSE and fimbria- mesovarian junction. Using conditional in vivo lineage tracing we identify embryonic and early neonate Lgr5+ populations as stem/progenitor cells contributing to the development of adult OSE and granulosa cell lineages, as well as the epithelia of the mesovarian and oviduct including its distal opening, fimbria. Long-term lineage tracing reveals that adult OSE-resident Lgr5+ populations contribute to epithelial homeostasis and OSE regenerative repair in vivo. Thus, Lgr5 is a marker of stem/progenitor cells of the ovary and tubal epithelia. Ovarian surface epithelium from pooled batches of Lgr5-eGFP-CreERT2 mice (n=8, per array) were sorted for cells expressing either high or low EGFP. Total RNA from three technical replicates per sorted population (Lgr5-high or Lgr5-low) was extracted with the RNeasy Micro Kit (QIAGEN), DNaseI-treated, and amplified with the Ovation Pico WTA V2 (NuGEN Technologies). Single-stranded cDNA amplification products were purified using QIAquick PCR Purification Kit (QIAGEN). cDNA was biotinylated using the Encore Biotin Module (NuGEN Technologies). Biotiylated cDNA was hybridized to Affymetrix Mouse Genechip ST 2.0 expression arrays.
Project description:Perturbed intestinal epithelial homeostasis demonstrated as decreased Lgr5+ intestinal stem cells (Lgr5 ISCs) and increased secretory lineages were observed in our study where Lkb1 was specfically deleted in Lgr5 ISCs using Lgr5-EGFP-creERT2 (Tamoxifen) deletor. To gain mechanistic insight how Lkb1 maintains intestinal epithelial stem cell homeostasis, Lkb1 deficient ISCs (Lgr5-high cells) and progenitors (Lgr5-low cells) are isolated by flow cytometry and profiled by RNA sequencing to compare with controls (Lkb1 wild type ISCs and progenitors).
Project description:Purpose: The goal of the study was to investigate the effect of Neuregulin 1 (NRG1) on intestinal crypt-based columnar stem cells, their progenitors and differentiated cells. Methods: Lgr5-EGFP C57BL/6 male mice (11-15 week-old, littermates) were injected with two intra-peritoneal doses of NRG1 daily (7.5 µg every 12 hours) or vehicle control (PBS) for 5 days (n=3). On day 6, small intestinal tissues were collected and several intestinal cell populations isolated by FACS based on Lgr5-GFP and CD24 expression [CBC stem cells (Lgr5high-CD24low), their immediate progenitors (Lgr5med-CD24low), subsequent progenitors (Lgr5low-CD24low) and differentiated cells (double negative)]. RNA was then extracted for each cell population and RNA sequencing analysis conducted.
Project description:Lgr5-EGFP-IRES-Cre-ERT2 mice were exposed to azoxymethane/dextrane sodium sulfate (AOM/DSS) which induces inflammation-driven colon tumors. Tumors were then flow-sorted into fractions of epithelial cells that expressed high or low levels of Lgr5. To exclude that transcriptional differences between Lgr5 high and low mouse colon tumor cells were imposed by distinct patterns of chromosomal aberrations in the two cell fractions, we also performed array comparative genomic hybridization (aCGH) from these tumors. All eight analyzed tumors were chromosomally stable, and thus, no difference between Lgr5 high and low cells could be detected. AOM/DSS-induced mouse colon tumors were flow-sorted into Lgr5 high and low cells before aCGH was performed. Biological replicates: 8. Two CGH array platforms.