R-spondin (Rspo) signaling is crucial for stem cell renewal and tissue homeostasis in the gastrointestinal tract. In the stomach, Rspo is secreted from myofibroblasts and controls epithelial gland regeneration by inducing proliferation of Wnt-responsive Axin2+ cells in the isthmus of the gland. Infection with H. pylori results in increased expression of stromal Rspo, leading to an expansion of Axin2+ isthmus stem cells and gland hyperplasia. Lgr5+ cells in the gland base are exposed to Rspo3 but the effects of this are not well understood. Here we demonstrate that apart from its activity as a mitogen, endogenous Rspo3 regulates gene expression of Lgr5+ cells in the gastric gland base. Surprisingly, Rspo3 induces differentiation within the Lgr5+ compartment towards secretory deep mucous cells. Moreover, the Rspo3-Lgr5 axis turns out to be a stimulus of epithelial antimicrobial defense. Infection with H. pylori induces a strong antimicrobial response, with Lgr5+ cells expressing antimicrobial compounds that are secreted into the lumen in an Rspo3-dependent manner. Depletion of Lgr5+ cells or knockout of Rspo3 in myofibroblasts leads to hyper-colonization of gastric glands, including the stem cell compartment, whereas systemic application of recombinant Rspo clears H. pylori from the glands. We provide an intriguing, unexpected feature of the Rspo3-Lgr5 axis in the stomach, exhibiting antimicrobial self-protection of the gland to protect the stem cell compartment from invading pathogens. Overall design: Lgr5eGFP reporter mice were infected with H. pylori for 2 months, uninfected mice served as controls. Mice were sacrificed and isolated, sorted Lgr5eGFP+ cells from the stomach antrum were used for single cell RNAseq using the 10x genome platform.
R-spondin-3 induces secretory, antimicrobial Lgr5<sup>+</sup> cells in the stomach.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Plasmacytoid dendritic cells and C1q differentially regulate inflammatory gene induction by lupus immune complexes.
Specimen part, Treatment, Subject
View SamplesThe goal of this study was to determine what genes are up- and down-regulated in response to lupus immune complexes in purified CD14+ monocyte stimulations. Our results have shown that novel genes are induced by immune complexes but the response is less robust when using purified monocytes versus total PBMCs
Plasmacytoid dendritic cells and C1q differentially regulate inflammatory gene induction by lupus immune complexes.
Specimen part, Treatment, Subject
View SamplesIn most embryos, the mid-blastula transition is a complex process featuring maternal RNA degradation, cell cycle pause, zygotic transcriptional activation and morphological changes. The nucleocytoplasmic (N/C) ratio has been proposed to control the multiple events at MBT. To understand the global transcriptional response to the changes of the N/C ratio, we profiled wild type and haploid embryos using cDNA microarrays at three developmental stages.
Coupling of zygotic transcription to mitotic control at the Drosophila mid-blastula transition.
No sample metadata fields
View SamplesKaposis sarcoma-associated hepesvirus (KSHV) encodes four genes with homology to human interferon regulatory factors (IRFs). One of these IRFs, the viral interferon regulatory factor 3 (vIRF-3) is expressed in latently infected PEL cells and required for their continuous proliferation. Moreover, vIRF-3 is known to be involved in modulation of the type I interferon response.
Kaposi's sarcoma-associated herpesvirus viral interferon regulatory factor 3 inhibits gamma interferon and major histocompatibility complex class II expression.
Specimen part, Cell line
View SamplesThe Early Growth Response (Egr) family of transcription factors consists of 4 members (Egr1-4) that are expressed in a wide variety of cell types. A large body of evidence point to a role for Egr transcription factors in growth, survival, and differentiation. A major unanswered question is whether Egr transcription factors serve similar functions in diverse cell types by activating a common set of target genes. Signal transduction cascades in neurons and lymphocytes show striking parallels. Activation of either cell type activates the Ras-MAPK pathway and, in parallel, leads to increases in intracellular calcium stimulating the calcineurin-NFAT pathway. In both cell types, the strength of the activation signal affects the cellular outcomes and very strong stimuli lead to cell death. Notably both these pathways converge on the induction of Egr genes. We believe that downstream targets of Egr transcription factors in lymphocytes may also be activated by Egr factors in activated neurons. There is precedence for common target gene activation in these two cell types: apoptosis in both activated T cells and methamphetamine stimulated neurons occurs via FasL induction by NFAT transcription factors. We propose to use developing T lymphocytes (thymocytes) as a model system for discovery of Egr-dependent target genes for several reasons. First, we have observed a prominent survival defect in thymocytes from mice deficient in both Egr1 and Egr3 (1/3 DKO) and a partial differention block in the immature double negative (DN) stage. In addition, thymocytes are an easily manipulatable cell type, and the DN subpopulation affected in 1/3 DKO mice can be isolated to very high purity. We anticipate that 1/3 DKO thymocytes will provide an excellent experimental system that will provide insight into Egr-dependent transcription in neuronal development, activation, and death.
Redundant role for early growth response transcriptional regulators in thymocyte differentiation and survival.
No sample metadata fields
View SamplesWe report a comprehensive large-scale expression profiling analysis of mammalian male germ cells undergoing mitotic growth, meiosis and gametogenesis using High Density Oligonucleotide Microarrays and highly enriched cell populations. Among 11955 rat loci investigated, 1268 were identified as differentially transcribed in germ cells at subsequent developmental stages as compared to total testis, somatic Sertoli cells as well as brain and skeletal muscle controls. The loci were organized into four expression clusters that correspond to somatic, mitotic, meiotic and post-meiotic cell types. This work provides information about expression patterns of approximately 200 genes known to be important during male germ cell development. Approximately 40 of those are included in a group of 121 transcripts for which we report germ cell expression and lack of transcription in three somatic control cell types. Moreover, we demonstrate the testicular expression and transcriptional induction in mitotic, meiotic and/or post-meiotic germ cells of 293 as yet uncharacterized transcripts some of which are likely to encode factors involved in spermatogenesis and fertility. This group also contains numerous potential germ cell specific targets for innovative contraceptives. A graphical display of the data is conveniently accessible through the GermOnline database at <a href="http://www.germonline.org" target="_blank">http://www.germonline.org</a>.
Expression profiling of mammalian male meiosis and gametogenesis identifies novel candidate genes for roles in the regulation of fertility.
Sex, Age, Specimen part
View SamplesSurgical interventions on blood vessels bear a risk for intimal hyperplasia and atherosclerosis as a consequence of injury. A specific feature of intimal hyperplasia is the loss of vascular smooth muscle cell (VSMC) differentiation gene expression. We hypothesized that immediate responses following injury induce vascular remodeling. To differentiate injury due to trauma, reperfusion and pressure changes we analyzed vascular responses to carotid artery bypass grafting in mice compared to transient ligation. As a control, the carotid artery was surgically laid open only. In both, bypass or ligation models, the inflammatory responses were transient, peaking after 6h, whereas the loss of VSMC differentiation gene expression persisted. Extended time kinetics showed that transient carotid artery ligation was sufficient to induce a persistent VSMC phenotype change throughout 28 days. Transient arterial ligation in ApoE knockout mice resulted in atherosclerosis in the transiently ligated vascular segment but not on the not-ligated contralateral side. The VSMC phenotype change could not be prevented by anti-TNF antibodies, Sorafenib, Cytosporone B or N-acetylcysteine treatment. Surgical interventions involving hypoxia/reperfusion are sufficient to induce VSMC phenotype changes and vascular remodeling. In situations of a perturbed lipid metabolism this bears the risk to precipitate atherosclerosis. Overall design: Comparison of mRNA changes between control tissue and bypass grafts perfused for 1, 6 and 24h. Number of replicated per group =4-5
Hypoxia/reperfusion predisposes to atherosclerosis.
Sex, Specimen part, Cell line, Subject
View SamplesCDKN1B (p27) was formally established as a tumor suppressor gene (tsg) following the identification of inactivating germline mutations in rats (MENX syndrome) and patients (MEN4 syndrome) developing multiple neuroendocrine tumors (NETs). MENX-affected rats are homozygous for the predisposing p27 mutation, suggesting a canonical tsg function. In contrast, mice heterozygous for a defective Cdkn1b allele are already predisposed to tumor formation (haploinsufficiency). We here report that heterozygous mutant rats (p27+/mut) develop the same NETs seen in the homozygous (p27mut/mut) animals but with slower progression. In the tumors of p27+/mut rats, the wild-type allele is neither lost nor silenced, implying that p27 is haploinsufficient for tumor suppression also in this model.
Characterization of neuroendocrine tumors in heterozygous mutant MENX rats: a novel model of invasive medullary thyroid carcinoma.
Age
View SamplesPheochromocytomas (PCC) are mostly benign tumors, amenable to complete surgical resection. However, 1017% of cases can become malignant, and once metastasized, there is no curative treatment for this disease. Given the need to identify effective therapeutic approaches for PCC, we evaluated the antitumor potential of the dual PI3K/mTOR inhibitor BEZ235 against these tumors. We employed an in vivo model of endogenous PCCs (MENX mutant rats), which closely recapitulate the human tumors. Mutant rats with PCCs were treated with 2 doses of BEZ235 (20 and 30 mg/kg), or with placebo, for 2 weeks. Treatment with BEZ235 induced cytostatic and cytotoxic effects on rat PCCs, which could be appreciated by both staining the tumors ex vivo with appropriate markers, and non-invasively by functional imaging (diffusion weighted-DW-MRI) in vivo.
Targeting PI3K/mTOR signaling exerts potent antitumor activity in pheochromocytoma in vivo.
Sex, Age, Specimen part, Treatment
View Samples