The thymic microenvironment is essential for proper differentiation and selection of thymocytes.Thymic involution in aged mice results in decreased T cell output and immune function. Here we use gene expression profiling of FACS sorted thymic stromal subsets to identify molecular mediators of thymocyte: stromal cell interactions, as well as gene expression changes thymic stromal subsets during early stages of thymic involution .
Global transcriptional profiling reveals distinct functions of thymic stromal subsets and age-related changes during thymic involution.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThe PA0336 protein from Pseudomonas aeruginosa belongs to the family of widely distributed Nudix pyrophosphohydrolases which catalyze the hydrolysis of pyrophosphate bonds in a variety of nucleoside diphosphate derivatives. The amino acid sequence of the PA0336 protein is highly similar to that of the RppH Nudix RNA pyrophosphohydrolase from E. coli which removes pyrophosphate from 5'-end of triphosphorylated RNA transcripts. Trans-complementation experiments showed that the P. aeruginosa enzyme can functionally substitute for RppH in E. coli cells indicating that, similarly to RppH, the Pseudomonas hydrolase mediates RNA turnover in vivo. In order to elucidate the biological significance of the PA0336 protein in Pseudomonas cells, a PA0336 mutant strain was constructed. The mutated strain considerably increased level of the virulence factor pyocyanin compared to wild type, suggesting that PA0336 could be involved in down-regulation of P. aeruginosa pathogenicity. This phenotype was reversed by complementation with the wild type, but not catalytically inactive PA0336, indicating that the catalytic activity was indispensable for its biological function. To study the role of PA0336 further, transcriptomes of the PA0336 mutant and the wild type strain were compared using RNA sequencing. The cellular level of a number of transcripts was affected by the lack of PA0336. We focused our attention on pathogenesis-related genes. Up-regulated in the PA0336 mutant were transcripts coding for, i. a., proteins involved in the regulation and/or production of pyocyanin, biofim-associated alginates and exotoxins. The results from the global analysis were verified by determining the cellular level of chosen transcripts by quantitative RT-PCR method. Pathogenesis tests in Caenorhabditis elegans showed that the PA0336 mutant of P. aeruginosa was significantly more virulent than the parental strain, confirming further that the P. aeruginosa RNA pyrophosphohydrolase PA0336 modulates bacterial pathogenesis by down-regulating production of virulence factors. Overall design: Study comparing RNA expression of P. aeruginosa PA0336 mutant strain with wild type reference, both in biological triplicates, by RNA-seq performed on Ion Torrent Proton platform
Nudix-type RNA pyrophosphohydrolase provides homeostasis of virulence factor pyocyanin and functions as a global regulator in Pseudomonas aeruginosa.
Cell line, Subject
View SamplesWe analyzed the transcriptional profile of colon and small-intestinal (SI) tissues in response to ex-vivo colonization with members of the gut microbiota. Tissues were dissected from SPF or GF mice, and connected to the ex-vivo gut organ culture system. Then, microbial cultures or fecal samples were infused into the lumen, and tissues were processed in different time points, as indicated below.
An Intestinal Organ Culture System Uncovers a Role for the Nervous System in Microbe-Immune Crosstalk.
Sex, Age
View SamplesAbstract: Transcriptome analysis was applied to characterize the physiological activities of Pseudomonas aeruginosa grown for three days in drip-flow biofilm reactors. Conventional applications of transcriptional profiling often compare two paired data sets that differ in a single experimentally controlled variable. In contrast this study obtained the transcriptome of a single biofilm state, ranked transcript signals to make the priorities of the population manifest, and compared rankings for a priori identified physiological marker genes between the biofilm and published data sets.
Physiology of Pseudomonas aeruginosa in biofilms as revealed by transcriptome analysis.
Treatment
View SamplesUsing a mouse model overexpressing human SNCA and profiling the hippocampal transcriptome, we assessed gene-environment interactions to reveal perturbations in gene expression and their modulation through long-term enriched environment (EE) exposure. We observed that EE prevented perturbations of genes attributed to neuronal and glial cell types and linked to glutamate signaling, calcium homeostasis, inflammation, and related processes of SNCA biology. Cluster and promoter analyses suggested driver genes that specifically responded to the EE, and pointed to a pivotal role of Egr1 to have hierarchically activated other drivers. We suggest a model in which EE-induced driver genes prevent and counter-balance perturbations of SNCA overexpression, restoring a largely normalized gene expression profile and system state. Overall design: Using a 2x2 factorial design, we cross-compared a line of transgenic mice overexpressing human SNCA with wildtype animals, and the effects of a long-term EE with standard housing conditions. Employing RNA-seq, we profiled gene expression in the hippocampus of 12-month-old female animals.
Environmental Enrichment Prevents Transcriptional Disturbances Induced by Alpha-Synuclein Overexpression.
Age, Specimen part, Cell line, Subject
View SamplesThe gene expression pathways leading to muscle pathology in facioscapulohumeral dystrophy (FSHD) remain to be elucidated. This muscular dystrophy is caused by a contraction of an array of tandem 3.3-kb repeats (D4Z4) at 4q35.2. We compared expression of control and FSHD myoblasts and myotubes (three preparations each) on exon microarrays (Affymetrix Human Exon 1.0 ST) and validated FSHD-specific differences for representative genes by qRT-PCR on additional myoblast cell strains. The FSHD and control myoblasts used for these experiments were shown to grow and differentiate into myotubes equally efficiently as control myoblasts. There were no significant FSHD-control differences in RNA levels for MYOD1 and MYOG at the myoblast and myotube stages and for MYF5 and MYF6 at the myoblast stage. In contrast, 295 other genes were dysregulated at least 2-fold in FSHD vs. control myoblasts (p <0.01, adjusted for multiple comparisons).
Gene expression during normal and FSHD myogenesis.
Specimen part
View SamplesGene expression profiling using microarray has been limited to profiling of differentially expressed genes at comparison setting since probesets for different genes have different sensitivities. We overcome this limitation by using a very large number of varied microarray datasets as a common reference, so that statistical attributes of each probeset, such as dynamic range or a threshold between low and high expression can be reliably discovered through meta-analysis. This strategy is implemented in web-based platform named Gene Expression Commons (http://gexc.stanford.edu/ ) with datasets of 39 distinct highly purified mouse hematopoietic stem/progenitor/functional cell populations covering almost the entire hematopoietic system. Since the Gene Expression Commons is designed as an open platform, any scientist can explore gene expression of any gene, search by expression pattern of interest, submit their own microarray datasets, and design their own working models.
Gene Expression Commons: an open platform for absolute gene expression profiling.
Sex, Age
View SamplesDupuytren's contracture (DC) is the most common inherited connective tissue disease of humans and is hypothesized to be associated with aberrant wound healing of the palmar fascia. Fibroblasts and myofibroblasts are believed to play an important role in the genesis of DC and the fibroproliferation and contraction that are hallmarks of this disease. This study compares the gene expression profiles of fibroblasts isolated from DC patients and controls in an attempt to identify key genes whose regulation might be significantly altered in fibroblasts found within the palmar fascia of Dupuytren's patients. Total RNA isolated from diseased palmar fascia (DC) and normal palmar fascia (obtained during carpal tunnel release; 6 samples per group) was subjected to quantitative analyses using two different microarray platforms (GE Code Link and Illumina) to identify and validate differentially expressed genes. The data obtained was analyzed using The Significance Analysis of Microarrays (SAM) software through which we identified 69 and 40 differentially regulated gene transcripts using the CodeLink and Illumina platforms, respectively. The CodeLink platform identified 18 upregulated and 51 downregulated genes. Using the Illumina platform, 40 genes were identified as downregulated, eleven of which were identified by both platforms. Quantitative RT-PCR confirmed the downregulation of three high-interest candidate genes which are all components of the extracellular matrix: proteoglycan 4 (PRG4), fibulin-1 (FBLN-1) transcript variant D, and type XV collagen alpha 1 chain. Overall, our study has identified a variety of candidate genes that may be involved in the pathophysiology of Dupuytren's contracture and may ultimately serve as attractive molecular targets for alternative therapies.
Identification of differentially expressed genes in fibroblasts derived from patients with Dupuytren's Contracture.
Specimen part, Disease
View SamplesDystonia is characterized by involuntary muscle contractions. Its many forms are genetically, phenotypically and etiologically diverse and it is unknown whether their pathogenesis converges on shared pathways. Mutations in THAP1, a zinc-finger transcription factor, cause DYT6, but its neuronal targets and functions are unknown. We used RNA-Seq to assay the in vivo effect of a heterozygote Thap1C54Y or ?Exon2 allele on the gene transcription signatures in neonatal mouse striatum and cerebellum. Enriched pathways and gene ontology terms include eIF2a Signaling, Mitochondrial Dysfunction, Neuron Projection Development, Axonal Guidance Signaling, and Synaptic Long Term Depression pathways, which are dysregulated in a genotype and tissue-dependent manner. Electrophysiological and neurite outgrowth assays confirmed the functional significance of those findings. Notably, several of these pathways were recently implicated in other forms of inherited dystonia, including DYT1. We conclude that dysfunction of these pathways may represent a point of convergence on the pathogenesis of unrelated forms of inherited dystonia. Overall design: We used RNA-Seq to assay the in vivo effect of a heterozygote Thap1C54Y or deltaExon2 allele on the gene transcription signatures in neonatal mouse striatum and cerebellum
Mutations in THAP1/DYT6 reveal that diverse dystonia genes disrupt similar neuronal pathways and functions.
Specimen part, Cell line, Subject
View SamplesPurpose: To ensure that ABX464 acted specifically on HIV splicing and did not significantly or globally affect the splicing events of human genes, we used an assembly approach of HIV (YU2 strain) putative transcripts and human long non-coding sequences from paired-reads (2x75bp) captured on a NimbleGen SeqCap® EZ Developer Library (Roche/NimbleGen). Methods: Cells were infected with 80 ng of p24/106 cells of the YU-2 strain for 4 to 6 hours and then rinsed with PBS before medium renewal, followed by high-throughput RNAseq from custom SeqCap EZ capture libraries. Each raw dataset of the samples contained between 5 and 30 million paired-end reads (75 bp), with an average of approximately 12 million raw reads per sample. Results: The raw reads were then cleaned and assembled per library to generate contigs, giving an average of 930 contigs per sample for further analyses. Conclusions: Our results show that high-throughput analyses coupled with bioinformatics-specific tools offers a comprehensive and more accurate view of mRNA splicing within a cell. Overall design: We used buffy coats from HIV-negative individuals were obtained from the local blood donation center, then human peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll (Histopaque, Sigma) gradient centrifugation. Cells were infected with 80 ng of p24/106 cells of the YU-2 strain for 4 to 6 hours and then rinsed with PBS before medium renewal.
Both anti-inflammatory and antiviral properties of novel drug candidate ABX464 are mediated by modulation of RNA splicing.
Specimen part, Treatment, Subject
View Samples