Oxidative stress is a hallmark of inflammation in infection or sterile tissue injury. We show that partially oxidized phospholipids of microvesicles (MVs) from plasma of patients with rheumatoid arthritis or cells exposed to oxidative stress induce activation of TLR4. MVs from healthy donors or reconstituted synthetic MVs can be converted to TLR4 agonists by limited oxidation, while prolonged oxidation abrogates the activity. Activation by MVs mimics the mechanism of TLR4 activation by LPS. However, LPS and MVs induce significantly different transcriptional response profile in mouse BMDMs with a strong inflammation-resolving component induced by the endogenous signals. MVs thus represent a ubiquitous endogenous danger signal released under the oxidative stress, which underlies the pervasive role of TLR4 signaling in inflammation.
Toll-like receptor 4 senses oxidative stress mediated by the oxidation of phospholipids in extracellular vesicles.
Sex
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 SamplesUnderstanding the structure and interplay of cellular signalling pathways is one of the great challenges in molecular biology. Boolean Networks can infer signalling networks from observations of protein activation. In situations where it is difficult to assess protein activation directly, Nested Effect Models are an alternative. They derive the network structure indirectly from downstream effects of pathway perturbations. To date, Nested Effect Models cannot resolve signalling details like the formation of signalling complexes or the activation of proteins by multiple alternative input signals. Here we introduce Boolean Nested Effect Models (B-NEM). B-NEMs combine the use of downstream effects with the higher resolution of signalling pathway structures in Boolean Networks. We show that B-NEMs accurately reconstruct signal flows in simulated data. Using B-NEM we then resolve BCR signalling via PI3K and TAK1 kinases in BL2 lymphoma cell lines.
Analyzing synergistic and non-synergistic interactions in signalling pathways using Boolean Nested Effect Models.
Specimen part, Cell line, Treatment
View SamplesPcG protein complex PRC2 is a methyltransferase specific for histone H3 lysine27, and H3K27me3 is essential for stable transcription silencing. Less well known but quantitatively much more important is the genome-wide role of PRC2 that dimethylates ~70% of total H3K27. Here we show that H3K27me2 occurs in inverse proportion to transcriptional activity in genes and intergenic regions and its loss results in global transcriptional derepression proportionally greatest in previously silent or weakly transcribed regions. H3K27me2 levels are controlled by opposing roaming activities of PRC2 and the H3K27 demethylase dUTX. Unexpectedly, we find an equally pervasive distribution of histone H2A ubiquitylated at lysine 118 (H2AK118ub), attributed to the RING1 subunit of PRC1-type complexes. Overall design: Examination of global changes in transcription genome-wide when E(z) is inactivated by monitoring total RNA from E(z) temperature-sensitive cells at 25°C and 31°C in duplicate
Genome-wide activities of Polycomb complexes control pervasive transcription.
Cell line, Subject
View SamplesTip60 is a key histone acetyltransferase (HAT) enzyme that plays a central role in diverse biological processes critical for general cell function, however the chromatin-mediated cell-type specific developmental pathways that are dependent exclusively upon the HAT activity of Tip60 remain to be explored. Here, we investigate the role of Tip60 HAT activity in transcriptional control during multicellular development, in vivo by examining genome-wide changes in gene expression in a Drosophila model system specifically depleted for endogenous dTip60 HAT function. We show that amino acid residue E431 in the catalytic HAT domain of dTip60 is critical for the acetylation of endogenous histone H4 in our fly model in vivo, and demonstrate that dTip60 HAT activity is essential for multicellular development. Moreover, our results uncover a novel role for Tip60 HAT activity in controlling neuronal specific gene expression profiles essential for nervous system function as well as a central regulatory role for Tip60 HAT function in general metabolism.
Microarray analysis uncovers a role for Tip60 in nervous system function and general metabolism.
Specimen part
View SamplesAlveolar macrophages are the first line of defense against pathogens in the lungs of all mammalian species and therefore may constitute an appropriate therapeutic target cell in the treatment and prevention of opportunistic airway infections. Analysis of alveolar macrophages from several species has revealed a unique cellular phenotype and transcriptome, presumably linked to their distinct airway environment and function in host defense. The current study extends these findings to the horse.
Comparative transcriptome analysis of equine alveolar macrophages.
Treatment
View SamplesComparison of R1 embryonic stem cells response to DMSO and retinoic acid and control
Meta-analysis of differentiating mouse embryonic stem cell gene expression kinetics reveals early change of a small gene set.
Specimen part, Cell line, Compound
View SamplesTransgenic mice were generated that expressed the inhibitor of apoptosis and mitotic regulator survivin in pancreatic islet beta cells. Control non-transgenic or transgenic islets were then used in a model of islet transplantation in diabetic recipient mice and tested for their ability to correct hyperglycemia and allow long-term engraftment of tranplanted islets in vivo. Control or transgenic islets were analyzed by chip microarray for potential transcriptional changes associated with transgenic expression of survivin, in vivo.
Genome-wide analysis of Polycomb targets in Drosophila melanogaster.
Sex, Age, Specimen part
View SamplesTo try to investigate the mechanism behind the adaptive phenotypes observed in a mice model model of HD crossed with mGluR5 knockout, we analyzed whether mutated huntingtin (Htt) expression in a mGluR5 null background could be altering the expression of genes that might be involved in the pattern of Htt aggregation and HD-related locomotor alterations.
Metabotropic glutamate receptor 5 knockout promotes motor and biochemical alterations in a mouse model of Huntington's disease.
Age, Specimen part
View SamplesWe evaluated the trancriptome of primary cutaneous leisions caused by infection with Leishmania braziliensis. mRNA-seq technique was used to study the trancriptome of both host and parasite. A total of 10 samples was obtained from primary skin ulcers of two extreme clinical forms of American tegumentary leishmaniasis: (i) individuals that after antimonial treatment cured completely (localized cutaneous leishmaniasis - LCL, n=5) and (ii) individuals that developed mucosal lesions in naso and oropharynx areas long after initial healing of the cutaneous lesion (mucosal leishmaniasis - ML, n=5). The sequencing generated an average of 13+ 5 million reads per samples. The reads were aligned to Homo sapiens (USCS - hg19) and to Leishmania braziliensis (Wellcome Trust Sanger Institute - V2_29072008) genomes. Approximately, 15,000 human genes could be detected in the samples. Low amount of L. braziliensis reads did not allow the evaluation of parasite gene expression. LCL and ML samples showed different patterns of gene expression, indicating a more robust immune response in LCL individuals. In summary, this study demonstrated that next-generation sequencing can be used for identification of potentially important biological pathways and drug targets in the host-response to L. braziliensis infection and for characterization of a gene expression signature that could be used to predict the disease outcome. Moreover, we also showed the ability of this technique in, simultaneously, sequence host and pathogen mRNA. Overall design: Examination of 10 fragments of cutaneous lesions: 5 from localized cutaneous leishmaniasis patients and 5 from mucosal leishmaniasis patients.
Transcriptome patterns from primary cutaneous Leishmania braziliensis infections associate with eventual development of mucosal disease in humans.
Specimen part, Subject
View Samples