Cellular senescence is an irreversible proliferative arrest and can be triggered in many cell types in response to diverse forms of cellular damage or stress.
Senescence of activated stellate cells limits liver fibrosis.
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View SamplesMany traditional cytotoxic agents used in the treatment of cancer function by eliciting an apoptotic response in tumor cells. However, evasion of apoptosis by BCL-2 family members is often deregulated prior to therapeutic intervention leading to treatment failure. To address this, ABT-737 was rationally designed to target BCL-2-like family members and has shown promising results against tumor cells dependent on BCL-2 for their survival. One shortcoming is that MCL-1, a member of the BCL-2 family is poorly inhibited by ABT-737 and is a major cause of resistance. To gain insight into biological pathways that could circumvent this resistance, we designed an shRNA screen to identify novel sensitizers to ABT-737 by engineering MYC driven lymphomas that were resistant to ABT-737 due to endogenous MCL-1 expression. Utilizing this model, we performed a shRNA drop-out screen and identified Dhx9 as a target whose suppression sensitizes cells to ABT-737. DHX9 loss lead to replicative stress signaling, which in turn potently induced the BH3-only proteins, NOXA and PUMA, in a p53-dependent manner to curtail MCL-1 activity. Induction of NOXA is essential for ABT-737 sensitization. Our results ascribe a novel role for DHX9 in the replicative stress pathway and link DHX9 activity to p53 function in vivo.
RNAi screening uncovers Dhx9 as a modifier of ABT-737 resistance in an Eμ-myc/Bcl-2 mouse model.
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View SamplesChlamydia pneumoniae, an obligate intracellular bacterium, causes pneumonia in humans and mice. Toll-like receptors and the key adaptor molecule MyD88 play a critical role in inducing immunity against this microorganism and are crucial to survive the infection. To explore the influence of MyD88 on induction of immune responses in vivo on a genome wide level, WT or MyD88-/- mice were infected with C. pneumoniae upon anesthesia and the pulmonary transcriptome was analyzed three days later by microarrays. We find that the infection induced the transcription of 360 genes and repressed 18 genes in WT mice. Of these, 221 genes were not or weakly induced in lungs of MyD88-/- mice. This cluster contains primarily genes encoding for chemokines, cytokines and other immune effector molecules. Genes induced by interferons were abundant in a cluster of 102 genes which were only partially MyD88-dependent. Interestingly, a set of 37 genes were induced more strongly in MyD88-/- mice and most of them are involved in the regulation of cellular replication. In summary, ex vivo analysis of the pulmonary transcriptome upon infection with C. pneumoniae demonstrated a major impact of MyD88 on inflammatory responses but not on interferon-type responses, and identified MyD88-independent genes involved in cellular replication
MyD88-dependent changes in the pulmonary transcriptome after infection with Chlamydia pneumoniae.
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View SamplesThis experiment is an additional experiment to GSE6688. Mouse macrophages (ANA-1 cells) were infected in vitro with C. pneumoniae with a M.O.I. of 10. Twenty two genes were significantly upregulated. Examples of the most upregulated genes in mouse macrophages after C. pneumoniae infection are serum amyloid A3 (saa3), a protein that is mainly produced by activated macrophages during tissue injury or inflammation, MIP-2 (cxcl2) and irg1. Expression levels of all genes induced by C. pneumoniae in macrophages in vitro correlated with the results obtained from infected lungs from wild type mice (GSE6688), suggesting that this cell type participates in host defense in vivo against C. pneumoniae.
MyD88-dependent changes in the pulmonary transcriptome after infection with Chlamydia pneumoniae.
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View SamplesPurpose: to identify differentially regulated pathways and processes in the livers of neonatal Mdr+/- compared to Mdr+/+ mice and correlate these transcriptomics with hepatic lipdomics data Methods: Mdr2+/- mice were mated. There offspring with +/+, +/-, and -/- mdr2 genotypes were kept as litter mates until harvest of livers at 10 days of life. Lobe 1 and 2 were dissected and snap frozen in liquid nitrogen for subsequent RNA isolation and lipid extraction, respectively. RNA-seq libraries were prepared using Illumina TruSeq RNA prep kits and sequenced on the Illumina Hi-Seq 2000. Results: Approximately 20 million reads were mapped to the mm10 mouse genome build using attotations produced by the Ensembl project, which corresponded to 36,400 transcripts. Of these, over 600 transcripts exhibited differential regulation between Mdr+/+ and Mdr+/- samples. Conclusions: Our study supports a pro-inflammatory microenvironment in neonatal, non-infected mdr2+/- compared with wild type mice. Overall design: Hepatic mRNA profiles of Mdr2+/+ and +/- neonatal, BALB/C mice were generated through RNAsequencing.
Hepatic MDR3 expression impacts lipid homeostasis and susceptibility to inflammatory bile duct obstruction in neonates.
Specimen part, Cell line, Subject
View SamplesAnalysis of human primary macrophages after live Lactobacillus rhamnosus GG (LGG) or LC705 stimulation for 6h and 24h. The results reveal novel mechanisms for probiotics-induced activation of the healthy human innate immune system.
Nonpathogenic Lactobacillus rhamnosus activates the inflammasome and antiviral responses in human macrophages.
Specimen part, Time
View SamplesHuman adipose stem cells (ASCs) have been shown, in pre-clinical studies, to have therapeutic applicability in diverse fields, but a standard expansion method for clinical applications remains yet to be established. Isolated ASCs are typically expanded in medium containing fetal bovine serum (FBS). However, sera and other animal-derived culture reagents stage numerous safety issues in clinical therapy, including possible infections and severe immune reactions. By expanding the ASCs in medium containing human serum (HS), the problem can be eliminated.
Differential gene expression in adipose stem cells cultured in allogeneic human serum versus fetal bovine serum.
Specimen part
View SamplesThe optic vesicle comprises a pool of bi-potential progenitor cells from which the retinal pigment epithelium (RPE) and neural retina fates segregate during ocular morphogenesis. Several transcription factors and signaling pathways have been shown to be important for RPE maintenance and differentiation, but an understanding of the initial fate specification and determination of this ocular cell type is lacking. We show that Yap/Taz-Tead activity is necessary and sufficient for optic vesicle progenitors to adopt RPE identity in zebrafish. A Teadresponsive transgene is expressed within the domain of the optic cup from which RPE arises, and Yap immunoreactivity localizes to the nuclei of prospective RPE cells. yap (yap1) mutants lack a subset of RPE cells and/or exhibit coloboma. Loss of RPE in yap mutants is exacerbated in combination with taz (wwtr1) mutant alleles such that, when Yap and Taz are both absent, optic vesicle progenitor cells completely lose their ability to form RPE. The mechanism of Yap dependent RPE cell type determination is reliant on both nuclear localization of Yap and interaction with a Tead co-factor. In contrast to loss of Yap and Taz, overexpression of either protein within optic vesicle progenitors leads to ectopic pigmentation in a dosagedependent manner. Overall, this study identifies Yap and Taz as key early regulators of RPE genesis and provides a mechanistic framework for understanding the congenital ocular defects of Sveinsson’s chorioretinal atrophy and congenital retinal coloboma. Overall design: 60 pooled eyes from 36 hpf wild type or vsx2:Gal4/dsRed:14xUAS:YapS87A embryos were pooled for one sample. Three wild type and three vsx2:Gal4/dsRed:14xUAS:YapS87A pools were analyzed for RNA.
Yap and Taz regulate retinal pigment epithelial cell fate.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Requirement for the histone deacetylase Hdac3 for the inflammatory gene expression program in macrophages.
Specimen part, Treatment
View SamplesPan-Hdac inhibitors (HDACi) are endowed with a potent anti-inflammatory activity, but the relative role of each of the eleven Hdac proteins sensitive to HDACi to the inflammatory gene expression program is unknown. Using an integrated genomic approach we found that Hdac3-deficient macrophages are unable to activate almost half of the inflammatory gene expression program when stimulated with lipopolysaccharide (LPS). A large part of the activation defect is due to loss of basal and LPS-inducible expression of IFNb, which in basal cells maintains Stat1 protein levels, and after stimulation acts in an autocrine/paracrine manner to promote a secondary wave of Stat1-dependent gene expression. We show that loss of Hdac3-mediated repression of nuclear receptors leads to hyperacetylation of thousands of genomic sites and associated gene derepression. The upregulation of the constitutively expressed prostaglandin endoperoxide synthase, Ptgs1 (Cox-1), has a causative role in the phenotype, since its chemical inhibition reverts the Ifnb activation defect. These data may have relevance for the use of selective Hdac inhibitors as anti-inflammatory agents.
Requirement for the histone deacetylase Hdac3 for the inflammatory gene expression program in macrophages.
Specimen part, Treatment
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