The forkhead O transcription factors (FOXO) integrate a range of extracellular signals including growth factor signaling, inflammation, oxidative stress and nutrient availability, to substantially alter the program of gene expression and modulate cell survival, cell cycle progression, and many cell-type specific responses yet to be unraveled. Naive antigen-specific CD8+ T cells undergo a rapid expansion and arming of effector function within days of pathogen exposure, but in addition, by the peak of expansion, they form precursors to memory T cells capable of self-renewal and indefinite survival.
Differentiation of CD8 memory T cells depends on Foxo1.
Specimen part
View SamplesAn important but largely unmet challenge in understanding the mechanisms that govern formation of specific organs is to decipher the complex and dynamic genetic programs exhibited by the diversity of cell types within the tissue of interest. Here, we use an integrated genetic, genomic and computational strategy to comprehensively determine the molecular identities of distinct myoblast subpopulations within the Drosophila embryonic mesoderm at the time that cell fates are initially specified. A compendium of gene expression profiles was generated for primary mesodermal cells purified by flow cytometry from appropriately staged wild-type embryos and from twelve genotypes in which myogenesis was selectively and predictably perturbed. A statistical meta-analysis of these pooled datasetsbased on expected trends in gene expression and on the relative contribution of each genotype to the detection of known muscle genesprovisionally assigned hundreds of differentially expressed genes to particular myoblast subtypes. Whole embryo in situ hybridizations were then used to validate the majority of these predictions, thereby enabling true positive detection rates to be estimated for the microarray data. This combined analysis reveals that myoblasts exhibit much greater gene expression heterogeneity and overall complexity than was previously appreciated. Moreover, it implicates the involvement of large numbers of uncharacterized, differentially expressed genes in myogenic specification and subsequent morphogenesis. These findings also underscore a requirement for considerable regulatory specificity for generating diverse myoblast identities. Finally, to illustrate how the developmental functions of newly identified myoblast genes can be efficiently surveyed, a rapid RNA interference assay that can be scored in living embryos was developed and applied to selected genes. This integrated strategy for examining embryonic gene expression and function provides a substantially expanded framework for further studies of this model developmental system.
An integrated strategy for analyzing the unique developmental programs of different myoblast subtypes.
No sample metadata fields
View SamplesRecent genome-wide association studies (GWAS) have identified a number of novel genetic associations with complex human diseases. In spite of these successes, results from GWAS generally explain only a small proportion of disease heritability, an observation termed the missing heritability problem. Several sources for the missing heritability have been proposed, including the contribution of many common variants with small individual effect sizes, which cannot be reliably found using the standard GWAS approach. The goal of our study was to explore a complementary approach, which combines GWAS results with functional data in order to identify novel genetic associations with small effect sizes. To do so, we conducted a GWAS for lymphocyte count, a physiologic quantitative trait associated with asthma, in 462 Hutterites. In parallel, we performed a genome-wide gene expression study in lymphoblastoid cell lines (LCLs) from 96 Hutterites. We found significant support for genetic associations using the GWAS data when we considered variants near the 193 genes whose expression levels across individuals were most correlated with lymphocyte counts. Interestingly, these variants are also enriched with signatures of an association with asthma susceptibility, an observation we were able to replicate. The associated loci include genes previously implicated in asthma susceptibility, as well as novel candidate genes enriched for functions related to T cell receptor signaling and ATP synthesis. Our results, therefore, establish a new set of asthma susceptibility candidate genes. More generally, our observations support the notion that many loci of small effects influence variation in lymphocyte count and asthma susceptibility.
The combination of a genome-wide association study of lymphocyte count and analysis of gene expression data reveals novel asthma candidate genes.
Sex
View SamplesPowdery mildew, caused by the fungus Blumeria graminis (DC) Speer, is one of the most important foliar diseases of cereals worldwide. It is an obligate biotrophic parasite, colonising leaf epidermal cells to obtain nutrients from the plant cells without killing them. Syringolin A (sylA), a circular peptide secreted by the phytopathogenic bacterium Pseudomonas syringae pv. syringae, triggers a hypersensitive cell death reaction (HR) at infection sites when sprayed onto powdery mildew infected wheat which essentially eradicates the fungus. The rational was to identify genes whose expression was specifically regulated during HR, i.e. genes that might be involved in the switch of compatibility to incompatibility.<br></br>Powdery mildew-infected or uninfected plants were treated with syringolin two days after infection and plant material for RNA extraction was collected at 0.5, 1, 2, 4, 8, 12 hours after treatment (hat), resulting in an early (2 and 4 hat) and late pool (8 and 12 hat). Plant material that was uninfected prior to syringolin treatment was collected 8 and 12 hat (late pool of uninfected plant material), and 1 hat, respectively.
Transcriptional changes in powdery mildew infected wheat and Arabidopsis leaves undergoing syringolin-triggered hypersensitive cell death at infection sites.
Compound, Time
View SamplesStudy on selective vulnerability of certain brain regions to oxidative stress. Here we selected 4 brain regions (hippocampal CA1 and CA3, cerebral cortex, and cerebellar granular layer) to study this phenomenon.
Genomic and biochemical approaches in the discovery of mechanisms for selective neuronal vulnerability to oxidative stress.
Specimen part
View SamplesCraniosynostosis (CS) is the congenital premature fusion of one or more cranial sutures and represents the more prevalent craniofacial malformation in humans, with an overall incidence of 1 out of 2000-3000 live births. Non-syndromic craniosynostoses (NSC) are believed to be multifactorial disorders, with a strong genetic component, due to possible genegene or geneenvironment interactions that remain to be clearly identified. In this study we delved into the molecular signaling acting in calvarial tissue and cells from patients affected by nonsynodromic midline craniosynostosis, using a comparative analysis between fused and unfused sutures of each affected individuals. Using comparative microarray tissue gene expression profiling we have identified a subset of genes involved in the structure and function of the primary cilium, including the Bardet-Biedl syndrome 9 (BBS9) gene, which was recently associated to sagittal synostosis in a GWAS study. We therefore characterized BBS9 expression and cilium-related signaling in cells isolated from patients calvarial bone.
BBS9 gene in nonsyndromic craniosynostosis: Role of the primary cilium in the aberrant ossification of the suture osteogenic niche.
Sex, Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesGestational diabetes mellitus (GDM) affects approximately 18% of pregnancies in the United States and increases the risk of adverse health outcomes in the offspring. These adult disease propensities may be set by anatomical and molecular alterations in the placenta associated with GDM. To assess the mechanistic aspects of fetal programming, we measured genome-wide methylation (Infinium HumanMethylation450 Beadchips) and expression (Affymetrix Transcriptome Microarrays) in placental tissue of 41 GDM cases and 41 matched pregnancies without maternal complications from the Harvard Epigenetic Birth Cohort. Specific transcriptional and epigenetic perturbations associated with GDM status included alterations in the major histocompatibility complex (MHC) region, which were validated in an independent cohort, the Rhode Island Child Health Study. Gene ontology enrichment among gene regulation influenced by GDM revealed an over-representation of immune response pathways among differential expression, reflecting these coordinated changes in the MHC region. Our study represents the largest investigation of transcriptomic and methylomic differences associated with GDM, providing comprehensive insight into the molecular basis of GDM induced fetal (re)programming.
Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesTarget specific short single-stranded DNA (ssDNA) molecules, called aptamers, are auspicious ligands for numerous in vivo applications. However, aptamers are synthetic molecules, which might be recognized by the immune cells in vivo and induce an activation of the innate immune system. Thus, immune activation potential of synthetic ssDNA oligonucleotides (ODNs) was determined using a well established closed-loop circulation model. Fresh human blood was incubated at 37C for 2 or 4 hours with ssDNA ODNs (SB_ODN) or CpG ODN as positive control. Transcriptional changes were determined by microarray analyses. Blood samples containing SB_ODN demonstrated after 4 hours a significant regulation of 295 transcripts. Amongst others, CCL8, CXCL10, CCL7 and CXCL11 were highest regulated genes. Gene Ontology terms and KEGG pathway analyses exhibited that the differentially expressed genes belong to the transcripts that are regulated during an immune and inflammatory response, and were overrepresented in TLR signaling pathway. This study shows for the first time the potential of aptamers to activate immune system after systemic application into the human blood. Thus, we highly recommend performing of these preclinical tests with potential aptamer-based therapeutics.
Potential capacity of aptamers to trigger immune activation in human blood.
Sex, Specimen part, Treatment, Subject, Time
View SamplesWe report a time course of RNA-seq data from wild-type embryonic stem cells and embryonic stem cells in which the cardiogenic transcription factors ZNF503, ZEB2 and NKX2-5 are depleted with shRNAs differentiating along the cardiac lineage. Overall design: Biological replicates of RNA-seq data from embryonic stem cells differentiating along the cardiac lineage.
An Orthologous Epigenetic Gene Expression Signature Derived from Differentiating Embryonic Stem Cells Identifies Regulators of Cardiogenesis.
No sample metadata fields
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