One of the hallmarks of Pseudomonas aeruginosa cystic fibrosis (CF) infection is very high-cell-density (HCD) replication in the lung, allowing this bacterium to induce virulence controlled by HCD quorum-sensing systems. However, the nutrient sources sustaining HCD replication in this chronic infection is largely unknown. Hence, understanding the nutrient factors contributing to HCD in the CF lung will yield new insights into the 'metabolic pathogenicity' and potential treatment of CF infections caused by P. aeruginosa. Herein, we performed microarray studies of P. aeruginosa directly isolated from the CF lung to demonstrate its metabolic capability and virulence in vivo. Our in vivo microarray data, confirmed by real-time reverse-transcription-PCR, indicated P. aeruginosa expressed several genes for virulence, drug-resistance, and utilization of multiple nutrient sources (lung surfactant lipids and amino acids) contributing to HCD replication. The data also indicates deregulation of several pathways, suggesting in vivo evolution by deregulation of a large portion of the transcriptome during chronic CF infection. To our knowledge, this is the first in vivo transcriptome of P. aeruginosa in a natural CF infection, and it indicates several important aspects of pathogenesis, drug-resistance, and nutrient-utilization never before observed in vivo.
In vivo evidence of Pseudomonas aeruginosa nutrient acquisition and pathogenesis in the lungs of cystic fibrosis patients.
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View Samplesb-Oxidative enzymes for fatty acid degradation (Fad) of long-chain fatty acid (LCFA), a component of lung surfactant phosphatidylcholine, are induced in vivo during lung infection in cystic fibrosis patients, which could contribute to nutrient acquisition and pathogenesis of Pseudomonas aeruginosa. In addition, fatty acid biosynthesis (Fab) is essential for the syntheses of two virulence controlling acylated-homoserine-lactone molecules in this organism. We mapped the promoter regions of the fadBA5-operon (PA3014 and PA3013) and a fadE homologue (PA2815) involved in Fad and the fabAB-operon involved in Fab. Focusing on the transposon mutagenesis of strain PAO1 carrying the PfadBA5-lacZ fusion, we identified a regulator for the fadBA5-operon to be PsrA (PA3006). Transcriptome analysis of the DpsrA mutant indicates its importance in regulating b-oxidative enzymes, which confirms a previous proteomic study. We further showed that induction of the fadBA-operon responds to LCFA signals, and this induction requires the presence of PsrA, suggesting that PsrA binds to LCFA to derepress fadBA5. Electrophoresis mobility shift assay indicate specific binding of PsrA to the fadBA5-promoter region. This binding is disrupted by specific LCFA (C18:1D9, C16:0, and to a lesser extent C14:0), but not by the first intermediate of b-oxidation, acyl-CoA. We proposed that PsrA is a Fad-regulator that binds and responds to LCFA signals in Pseudomonas aeruginosa.
The Pseudomonas aeruginosa PsrA responds to long-chain fatty acid signals to regulate the fadBA5 beta-oxidation operon.
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View SamplesGenome-wide association studies (GWAS) have identified 19 risk variants associated with colorectal cancer. As most of these risk variants reside outside the coding regions of genes, we conducted cis-expression quantitative trait loci (cis-eQTL) analyses to investigate possible regulatory functions on the expression of neighboring genes.
cis-Expression QTL analysis of established colorectal cancer risk variants in colon tumors and adjacent normal tissue.
Disease, Disease stage
View SamplesIn this study, we explored transcriptional complexity in human neutrophils, cells generally regarded as nonspecific in their functions and responses. We studied distinct human disease phenotypes and found that, at the gene, gene isoform, and miRNA level, neutrophils exhibit considerable specificity in their transcriptomes. These findings were particularly striking for isoform usage. Thus, even cells whose responses are considered non-specific show tailoring of their transcriptional repertoire toward specific physiologic or pathologic contexts. These findings have important implications for our understanding of the link between gene expression and disease phenotypes.
No associated publication
Specimen part, Disease
View SamplesNeutrophils in children with the polyarticular form of juvenile idiopathic arthritis (JIA) display abnormal transcriptional patterns linked to fundamental metabolic derangements. These abnormalities include re-ordering of miRNA-RNA expression networks. In this study, we sought to determine the effects of therapy on miRNA-RNA networks in polyarticular JIA. We studied children with active JIA disease on therapy (ADM), children with inactive disease also on therapy (ID), and children with clinical remission on medication (CRM) using exon and miRNA microarrays and compared results to findings from healthy control (HC) children. We found substantial re-ordering of miRNA-RNA networks after the initiation of therapy. Each disease state was associated with a distinct transcriptional profile.
No associated publication
Specimen part, Disease, Disease stage
View SamplesThe polyarticular and oligoarticular forms of juvenile idiopathic arthritis are classified as distinct entities. At the same time, many children who present with an oligoarticular phenotype eventually evolve to a polyarticular disease pattern, suggesting that the phenotypes might share with overlapping molecular mechanisms. Using gene expression microarrays, we found that 14 genes in neutrophils and 55 genes in PBMC shows common patterns of differential expression when children with active oligoarticular and polyarticular JIA were compared with healthy controls. These results demonstrate that there are commonalities between oligoarticular and polyarticular JIA that suggest overlapping immune mechanisms.
No associated publication
Specimen part, Disease, Disease stage
View SamplesGlial progenitor cells comprise the most abundant population of progenitor cells in the adult human brain. They are responsible for CNS remyelination, and likely contribute to the astrogliotic response to brain injury and degeneration as well. Adult human GPCs are biased to differentiate as oligodendrocytes and elaborate new myelin, and yet they retain multilineage plasticity, and can give rise to neurons as well as astrocytes and oligodendrocytes once removed from the adult parenchymal environment. GPCs retain strong mechanisms for cell-autonomous self-renewal, and yet both their phenotype and fate may be dictated by their microenvironment. Using the transcriptional profiles of acutely isolated GPCs, we have begun to understand the operative ligand-receptor interactions involved in these processes, and have identified several key signaling pathways by which adult human GPCs may be reliably instructed to either oligodendrocytic or astrocytic fate. In addition, we have noted significant differences between the expressed genes and dominant signaling pathways of fetal and adult human GPCs, as well as between rodent and human GPCs. The latter data in particular call into question therapeutic strategies predicated solely upon data obtained using rodents, while perhaps highlighting the extent to which evolution has been attended by the phylogenetic modification of glial phenotype and function.
Fate determination of adult human glial progenitor cells.
Specimen part, Subject
View SamplesThis study investigates the effects of the aryl hydrocarbon receptor (AhR) ligands TCDD, PCB126 and PeCDF; the non-AhR ligand PCB153 and the binary mixture PCB126/PCB153 on hepatic gene expression in female sprague dawley rats. Rats were treated with toxicological equivalent doses of TCDD (100ng/kg), PeCDF (200ng/kg), PCB126 (1000ng/kg) and PCB153 (1000ug/kg) 5 days a week for 13 weeks.
Hepatic gene downregulation following acute and subchronic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.
Specimen part, Treatment
View SamplesThis study investigates the effects of the aryl hydrocarbon receptor (AhR) ligands TCDD and PCB126 on hepatic gene expression in female sprague dawley rats. Rats were treated with toxicological equivalent doses of TCDD (100ng/kg/day) (Toxic equivalence factor (TEF) = 1.0), PCB126 (30ng, 300ng or 1000ng/kg/day) (TEF = 0.1) or a vehicle control of corn oil:acetone (99:1) 5 days a week for 52 weeks.
Toxicogenomic analysis of exposure to TCDD, PCB126 and PCB153: identification of genomic biomarkers of exposure to AhR ligands.
Specimen part
View SamplesVitiligo Blood Transcriptomics Provides New Insights into Disease Mechanisms and Identifies Potential Novel Therapeutic Targets Abstract Background: Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state. Methods: We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy. Results: Unsupervised clustering methods of the VL-blood dataset demonstrate a disease-state-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as hidden (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional hot spot that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets. Conclusions: We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address a major gap in knowledge regarding the systemic changes underlying skin-specific manifestation of vitiligo. Several transcriptional hot spots observed in both environments offer prioritized targets for identifying disease risk genes. Finally, within the transcriptional framework of VL, we identify five novel molecules (STAT1, PRKCD, PTPN6, MYC and FGFR2) that lend themselves to being targeted by drugs for future potential VL-therapy.
Vitiligo blood transcriptomics provides new insights into disease mechanisms and identifies potential novel therapeutic targets.
Specimen part, Disease, Disease stage
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