IRF8 and IRF1 are transcriptional regulators that play critical roles in the development and function of myeloid cells, including activation of macrophages by pro-inflammatory signals such as interferon gamma. Loss of IRF8 or IRF1 function causes severe susceptibility to infections in mice and in humans. We used chromatin immunoprecipitation sequencing and RNA sequencing in wild type, and in IRF8 and IRF1 mutant primary macrophages to systematically catalog all the genes bound by (cistromes) and transcriptionally activated (regulomes) by IRF8, IRF1, PU.1 and STAT1 including modulation of epigenetic histone marks. Of seven binding combinations identified, two (cluster 1: IRF8/IRF1/STAT1/PU.1; cluster 5: IRF1/STAT1/PU.1) were found to have a major role in controlling macrophage transcriptional programs both at basal level and following IFN? activation. They direct expression of a set of genes, the IRF8/IRF1 regulome, that play critical roles in host inflammatory and anti-microbial defenses in mouse models of neuroinflammation and of pulmonary tuberculosis, respectively. In addition, this IRF8/IRF1 regulome is enriched for genes mutated in human primary immuno-deficiencies, and with loci associated for several inflammatory diseases in humans. Overall design: Sequencing of RNA extracted for untreated or 3h IFNg-treated bone marrow derived macrophages (BMDM) obtained from wild type (B6) and in IRF8 or IRF1 mutant mice.
The macrophage IRF8/IRF1 regulome is required for protection against infections and is associated with chronic inflammation.
Cell line, Treatment, Subject
View SamplesWhile the hypothalamo-pituitary-adrenal axis (HPA) activates a general stress response by increasing glucocorticoid (Gc) synthesis, biological stress resulting from infections triggers the inflammatory response through production of cytokines. The pituitary gland integrates some of these signals by responding to the pro-inflammatory cytokines IL6 and LIF and to a negative Gc feedback loop. The present work used whole-genome approaches to define the LIF/STAT3 regulatory network and to delineate cross-talk between this pathway and Gc action. Genome-wide ChIP-chip identified 3 449 STAT3 binding sites, whereas 2 396 genes regulated by LIF and/or Gc were found by expression profiling. Surprisingly, LIF on its own changed expression of only 85 genes but the joint action of LIF and Gc potentiated the expression of more than a thousand genes. Accordingly, activation of both LIF and Gc pathways also potentiated STAT3 and GR recruitment to many STAT3 targets. Our analyses revealed an unexpected gene cluster that requires both stimuli for delayed activation: 83% of the genes in this cluster are involved in different cell defense mechanisms. Thus, stressors that trigger both general stress and inflammatory responses lead to activation of a stereotypic innate cellular defense response.
Regulatory network analyses reveal genome-wide potentiation of LIF signaling by glucocorticoids and define an innate cell defense response.
Specimen part, Time
View SamplesGenes and pathways in which inactivation dampens tissue inflammation present new opportunities for understanding the pathogenesis of common human inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis and multiple sclerosis. We identified a mutation in the gene encoding the deubiquitination enzyme USP15 (Usp15L749R) that protected mice against both experimental cerebral malaria (ECM) induced by Plasmodium berghei and experimental autoimmune encephalomyelitis (EAE). Combining immunophenotyping and RNA sequencing in brain (ECM) and spinal cord (EAE) revealed that Usp15L749R-associated resistance to neuroinflammation was linked to dampened type I interferon responses in situ. In hematopoietic cells and in resident brain cells, USP15 was coexpressed with, and functionally acted together with the E3 ubiquitin ligase TRIM25 to positively regulate type I interferon responses and to promote pathogenesis during neuroinflammation. The USP15-TRIM25 dyad might be a potential target for intervention in acute or chronic states of neuroinflammation. Overall design: Sequencing of RNA extracted from target tissue in two experimental neuroinflammation models in wild-type (B6), USP15(L749R) and Trim25 KO mutant mice: (1) brains at day 3 and 5 following Plasmodium berghei ANKA (PbA) infection for the cerebral malaria model (ECM); and (2) spinal cords at day 7 following induction of experimental autoimmune encephalomyelitis (EAE) for B6 and Usp15 mutant mice only.
USP15 regulates type I interferon response and is required for pathogenesis of neuroinflammation.
Sex, Specimen part, Treatment, Subject
View SamplesPuberty unmasks or accelerates nephropathies, including the nephropathy of diabetes mellitus (DM). A number of cellular systems implicated in the kidney disease of DM interweave, forming an interdependent functional web. We performed focused microarray analysis to test the hypothesis that one or more genes in the transforming growth factor beta (TGF-) signaling system would be differentially regulated in male rats depending on the age of onset of DM.
Prepubertal onset of diabetes prevents expression of renal cortical connective tissue growth factor.
No sample metadata fields
View SamplesWe investigated how varying the composition of cell culture formulations and growing cancer cells at different densities might affect tumor cells genotype. Specifically, we compared gene expression profiles generated by human MDA-MB-231 human breast cancer cells cultured in different media (MEM, DMEM, or RPMI 1640) containing different concentrations of fetal bovine serum (FBS) or different sera (equine or bovine) that were grown at different cell densities.
Modulation of the cancer cell transcriptome by culture media formulations and cell density.
Specimen part, Cell line, Treatment
View SamplesPluripotent stem cells (PSCs) exist in multiple stable states, each with specific cellular properties and molecular signatures. The process by which pluripotency is either maintained or destabilized to initiate specific developmental programs is poorly understood. We have developed a model to predict stabilized PSC gene regulatory network (GRN) states in response to combinations of input signals. While previous attempts to model PSC fate have been limited to static cell compositions, our approach enables simulations of dynamic heterogeneity by combining an Asynchronous Boolean Simulation (ABS) strategy with simulated single cell fate transitions using a Strongly Connected Components (SCCs). This computational framework was applied to a reverse-engineered and curated core GRN for mouse embryonic stem cells (mESCs) to simulate responses to LIF, Wnt/ß-catenin, FGF/ERK, BMP4, and Activin A/Nodal pathway activation. For these input signals, our simulations exhibit strong predictive power for gene expression patterns, cell population composition, and nodes controlling cell fate transitions. The model predictions extend into early PSC differentiation, demonstrating, for example, that a Cdx2-high/Oct4-low state can be efficiently generated from mESCs residing in a naïve and signal-receptive state sustained by combinations of signaling activators and inhibitors. Overall design: Examination of perturbed PSCs versus control PSCs and mesoderm progenitors Mouse pluripotent stem cells were grown on tissue culture plates for two days in serum-containing, feeder free medium supplemented with the following cytokines/small molecules: 2i = CHIR99021 (Reagents Direct 27-H76 – 3µM) & PD0325901 (Reagents Direct 39-C68 – 1µM) Jaki = JAK inhibitor (EMD Millipore 420097 – 2.0µM) BMP = BMP4 (R&D Systems 314-BP-010 – 10ng/ml) Alk5i = ALK5 inhibitor II (Cedarlane ALX-270-445 - 10µM)
Modeling signaling-dependent pluripotency with Boolean logic to predict cell fate transitions.
Cell line, Treatment, Subject, Time
View SamplesSilicosis, a fibrotic granulomatous lung disease, may occur through accidental high-dose or occupational inhalation of silica, leading to acute/accelerated and chronic silicosis, respectively. While chronic silicosis has a long asymptomatic latency, lung inflammation and apoptosis are hallmarks of acute silicosis. In animal models, histiocytic granulomas develop within days after high-dose intratracheal silica instillation. However, following chronic inhalation of occupationally relevant doses of silica, discrete granulomas resembling human silicosis arise months after the final exposure without significant lung inflammation/apoptosis. To identify molecular events associated with chronic silicosis, lung RNAs from controls or chronically silica-exposed rats were analyzed by Affymetrix at 28 wk after silica exposures. Results suggested a significant upregulation of 144 genes and downregulation of seven genes. The upregulated genes included complement cascade, chemokines/chemokine receptors, G-protein signaling components, metalloproteases, and genes associated with oxidative stress. To examine the kinetics of gene expression relevant to silicosis, qPCR, ELISA, Luminex-bead assays, Western blotting, and/or zymography were performed on lung tissues from 4 d, 28 wk, and intermediate times after chronic silica exposure and compared with 14 d acute silicosis samples. Results indicated that genes regulating fibrosis (secreted phosphoprotein-1, CCL2, and CCL7), redox enzymes (superoxide dismutase-2 and arginase-1), and the enzymatic activities of matrix metalloproteinases 2 and 9 were upregulated in acute and chronic silicosis; however, proinflammatory cytokines were strongly upregulated only in acute silicosis. Thus, inflammatory cytokines are associated with acute but not chronic silicosis; however, genes regulating fibrosis, oxidative stress, and metalloproteases may contribute to both acute and chronic silicosis.
Fibrogenic and redox-related but not proinflammatory genes are upregulated in Lewis rat model of chronic silicosis.
Specimen part, Treatment
View SamplesProgesterone promotes differentiation coupled to proliferation and pro-survival in the breast, but inhibits estrogen-driven growth in the reproductive tract and ovaries. Herein, it is demonstrated, using progesterone receptor (PR) isoform-specific ovarian cancer model systems, that PR-A and PR-B promote distinct gene expression profiles that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target-gene p21 (CDKN1A) are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15 (CDKN2B). Chromatin immunoprecipitation (ChIP) assays performed on PR-isoform specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin marks. Overexpression of constitutively active FOXO1 in PR-A-expressing cells conferred robust ligand-dependent upregulation of the PR-B target genes GZMA, IGFBP1, and p21, and induced cellular senescence. In the presence of endogenous active FOXO1, PR-A was phosphorylated on Ser294 and transactivated PR-B at PR-B target genes; these events were blocked by the FOXO1 inhibitor (AS1842856). PR isoform-specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin; loss of progestin sensitivity correlated with high AKT activity.
Active FOXO1 Is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming.
Treatment, Time
View SamplesProgesterone receptors (PRs) are critical context-dependent transcription factors required for normal uterine (PR-A) and mammary gland (PR-B) development. Progesterone is proliferative in the breast, where PR-target genes include paracrine factors that mediate mammary stem cell self-renewal. In the context of altered signal transduction that typifies breast tumorigenesis, dysregulated (i.e. hyper-phosphorylated) PRs likely contribute to tumor progression by promoting cancer cell pro-survival and proliferation. Notably, in breast cancer cells, progestin-bound PRs induce rapid MAPK activation leading to selective regulation of growth-promoting genes by phosphorylated PR species. Functional domains within PR that interact with c-Src and estrogen receptors (ER) have been identified as indirect routes to MAPK activation. Herein, we describe a common docking (CD) domain located within the PR-B N-terminus, a motif first described in MAPKs that facilitates direct interactions between MAPKs and MEK1 or MAPK-phosphatases (MKPs). Mutation of negatively-charged amino acids, previously determined to be critical for CD domain function in MAPKs, within PR-B (mCD PR) did not alter MEK-binding or progestin-induced rapid signaling (i.e. MAPK activation) and PR transcriptional activity as measured by PRE-luciferase (reporter) assays. Microarray gene-expression analysis revealed that endogenous genes regulated by wt PR, but not mCD PR, are involved in critical cellular pathways regulating growth, proliferation, survival, and cancer. mCD PR failed to undergo ligand-induced phosphorylation on Ser81, a ck2-dependent site required for progestin-regulation of select growth-promoting genes (BIRC3, HSD112, HbEGF). Progestin-induced PR Ser81 phosphorylation mapped to CD domain-dependent binding of PR-B to MKP3, but did not require phosphatase activity. Receptors containing either mutant CD domains (mCD PR) or point mutations of Ser81 (S79/81A PR) failed to upregulate STAT5 and Wnt1, key PR-target gene products that act as critical mediators of mammary stem cell expansion. Inhibition of JAK/STAT signaling blocked progestin-induced STAT5 and Wnt1 expression. ChIP assays demonstrated that wt, but not phospho-mutant (S79/81A), PR-B was co-recruited to a PRE-containing enhancer region of the Wnt1 gene along with MKP3, ck2 and STAT5. Our studies reveal a novel scaffolding action of MKP3 mediated by interaction with the PR CD domain and required for ck2-dependent PR Ser81 phosphorylation. Co-regulation of select target genes by phospho-Ser81 PR and phospho-STAT5 is likely a global mechanism required for the activation of growth promoting programs active during normal mammary gland development and relevant to mechanisms of breast cancer progression.
A Common Docking Domain in Progesterone Receptor-B links DUSP6 and CK2 signaling to proliferative transcriptional programs in breast cancer cells.
Specimen part, Treatment
View SamplesThe progesterone receptor specific gene targets were investigated in ovarian and breast cancer cell lines where FOXO1 was found to be a primary factor that cooperates with PR to activate cellular senescence genes (including p21) specifically in ovarian cells.
Active FOXO1 Is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming.
Treatment, Time
View Samples