To delineate specific patterns of signaling networks activated by H5N1 we used a comparative systems biology approach analyzing gene expression in endothelial cells infected with three different human and avian influenza strains of high and low pathogenicity.
Essential impact of NF-kappaB signaling on the H5N1 influenza A virus-induced transcriptome.
No sample metadata fields
View SamplesMacrophages were infected with low (PR8) and high pathogenic influenza viruses (FPV and H5N1). To our surprise a genome-wide comparative systems biology approach revealed that in contrast PR8 infections with HPAIV H5N1 and FPV result in a reduced immune response of human macrophages contradicting a primary role of this cell type for the cytokine storm.
Highly pathogenic avian influenza viruses inhibit effective immune responses of human blood-derived macrophages.
Specimen part
View SamplesHighly pathogenic avian influenza viruses (HPAIV) induce severe inflammation in poultry and men. There is still an ongoing threat that these viruses may acquire the capability to freely spread as novel pandemic virus strains that may cause major morbidity and mortality. One characteristic of HPAIV infections is the induction of a cytokine burst that strongly contributes to viral pathogenicity. It has been suggested, that this cytokine overexpression is an intrinsic feature of infected cells and involves hyperinduction of p38 mitogen activated protein kinase (MAPK). Here we investigate the role of MAPK p38 signaling in the antiviral response against HPAIV in mice as well as in endothelial cells, the latter a primary source for cytokines during systemic infections.
Inhibition of p38 mitogen-activated protein kinase impairs influenza virus-induced primary and secondary host gene responses and protects mice from lethal H5N1 infection.
Specimen part
View SamplesHUVEC were left untreated or stimulated for 5h with 2 ng/ml TNF. Comparsion of the gene profiles revealed TNF-mediated gene expression changes in HUVEC.
TNF induces distinct gene expression programs in microvascular and macrovascular human endothelial cells.
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View SamplesHMEC cultures were left untreated or stimulated for 5h with 2 ng/ml TNF. Comparison of the gene expression profiles revealed the TNF-mediated gene expression changes.
TNF induces distinct gene expression programs in microvascular and macrovascular human endothelial cells.
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View SamplesUsing oligonucleotide microarray analysis, we identified 56 genes that were transcriptionally up-regulated and 69 that were suppressed upon exposure of endothelial cells to C. albicans. Among the regulated genes those attributed to the categories chemotaxis, signaling, and transcription and translation were remarkably overrepresented.
Candida albicans triggers activation of distinct signaling pathways to establish a proinflammatory gene expression program in primary human endothelial cells.
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View SamplesWe expressed a constitutively active mutant of MEK5 (MEK5D) in human primary endothelial cells (EC) to study the transcriptional and functional responses to Erk5 activation under static conditions.
Erk5 activation elicits a vasoprotective endothelial phenotype via induction of Kruppel-like factor 4 (KLF4).
Cell line
View SamplesThe alarmins myeloid-related protein (MRP) 8 and MRP14 are the dominant cytoplasmic proteins in phagocytes. After release by activated phagocytes extracellular MRP8/MRP14 complexes promote inflammation in many diseases, including infections, allergies, autoimmune diseases, rheumatoid arthritis or inflammatory bowel disease. As receptors for the pro-inflammatory effects of human MRP8, the active component of the MRP8/MRP14-complex, Toll-like receptor (TLR) 4 and the multi-ligand receptor of advanced glycation end products (RAGE) are controversial discussed. Using a comparative bioinformatics analysis between genome-wide response patterns of monocytes to MRP8, endotoxin and different cytokines we demonstrated a dominant role of TLR4 during MRP8-mediated phagocyte activation. The relevance of this signaling pathway could be confirmed in independent cell models for TLR4 and RAGE dependent signaling in mouse and man. In addition to well-known proinflammatory functions of MRP8 our systems biology approach unraveled a novel anti-apoptotic effect of MRP8 on monocytes which was confirmed in independent functional experiments. Our data define the dominance of the TLR4-MRP8 axis in activation of human phagocytes which represents a novel attractive target for modulation of overwhelming innate immune responses.
Transcriptome assessment reveals a dominant role for TLR4 in the activation of human monocytes by the alarmin MRP8.
Specimen part, Treatment
View SamplesWe disprove that the impaired Myd88-dependent proinflammatory response of neonatal monocytes is a correlate for immaturity and confirm it as display of transient alarmin-mediated stress tolerization. We find a strong inducibility of TRIF-dependent genes in neonatal monocytes by LPS but a barely detectable expression at baseline.
S100-alarmin-induced innate immune programming protects newborn infants from sepsis.
Specimen part, Treatment
View SamplesWe analyzed the transcriptome of the C57BL/6J mouse hypothalamus, hippocampus, neocortex, and cerebellum to determine estrous cycle-specific changes in these four brain regions. We found almost 16,000 genes are present in one or more of the brain areas but only 210 genes, ~1.3%, are significantly changed as a result of the estrous cycle. The hippocampus has the largest number of differentially expressed genes (DEGs) (82), followed by the neocortex (76), hypothalamus (63), and cerebellum (26). Most of these DEGs (186/210) are differentially expressed in only one of the four brain regions. A key finding is the unique expression pattern of growth hormone (Gh) and prolactin (Prl). Gh and Prl are the only DEGs to be expressed during only one stage of the estrous cycle (metestrus). To gain insight into the function of the DEGs, we examined gene ontology and phenotype enrichment and found significant enrichment for genes associated with myelination, hormone stimulus, and abnormal hormone levels. Additionally, 61 of the 210 DEGs are known to change in response to estrogen in the brain. 50 genes differentially expressed as a result of the estrous cycle are related to myelin and oligodendrocytes and 12 of the 63 DEGs in the hypothalamus are oligodendrocyte- and myelin-specific genes. This transcriptomic analysis reveals that gene expression in the female mouse brain is remarkably stable during the estrous cycle and demonstrates that the genes that do fluctuate are functionally related. Overall design: Hypothalamus, hippocampus, neocortex, and cerebellum mRNA from adult female C57BL/6J (B6) mice were analyzed by RNA sequencing of 3 biological replicates for each of the 4 stages of the estrous cycle using an Illumina HiSeq 2500
The stability of the transcriptome during the estrous cycle in four regions of the mouse brain.
Sex, Age, Specimen part, Cell line, Subject
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