High fat feeding is deleterious for skeletal muscle metabolism, while exercise has well documented beneficial effects for these same metabolic features. To identify the genomic mechanisms by which exercise ameliorates some of the deleterious effects of high fat feeding, we investigated the transcriptional and epigenetic response of human skeletal muscle to 9 days of a high-fat diet (HFD) alone (Sed-HFD) or in combination with resistance exercise (Ex-HFD), using genome-wide profiling of gene expression (by RNA-seq) and DNA methylation (by Reduced Representation Bisulfite Sequencing). HFD markedly induced expression of immune and inflammatory genes which was not attenuated by Ex. In contract, Ex markedly remodelled expression of genes associated with muscle growth and structure. We detected marked DNA methylation changes following HFD alone and in combination with Ex. Among the genes that showed significant association between DNA methylation changes and gene expression were glycogen phosphorylase, muscle associated (PYGM), which was epigenetically regulated in both groups, and angiopoiten like 4 (ANGPTL4), which was regulated only following Ex. We conclude that Short-term Ex does not prevent HFD-induced inflammatory response, but provokes a genomic response that may preserve skeletal muscle from atrophy. Epigenetic adaptation provides important mechanistic insight into the gene specific regulation of inflammatory and metabolic processes in human skeletal muscle. Overall design: Sedentary or exercising human subjects undergo high-fat diet intervention.
Transcriptomic and epigenetic responses to short-term nutrient-exercise stress in humans.
Specimen part, Subject, Time
View SamplesThe goal of this analysis was to utilize microarray profiling to identify basal alterations in gene expression in response to TFAM depletion and mtDNA stress.
Mitochondrial DNA stress primes the antiviral innate immune response.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesMedulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesMedulloblastoma (MB), a tumor of the cerebellum, is the most common malignant brain tumor in children. One third of all human MB exhibits a gene expression signature of Sonic hedgehog (Shh) signaling. Hedgehog (Hh) pathway inhibitors have shown efficacy in clinical trials for MB, however, tumors develop resistance to these compounds, highlighting the need to identify additional therapeutic targets for treatment. We have identified a role for Norrin signaling in tumor initiation in the Patched (Ptch) mouse model of MB. Norrin is a secreted factor that functions as an atypical Wnt by binding to the Frizzled4 (Fzd4) receptor on endothelial cells to activate canonical beta-catenin-mediated Wnt signaling pathway. In the cerebellum, activation of Norrin/Fzd4 signaling is required for the establishment and maintenance of the blood brain barrier (BBB). We have identified a role for Norrin signaling in the stroma as a potent tumor inhibitory signal. Inactivation of Norrin in Ptch+/- mice significantly shortens latency and increases MB incidence. This phenotype is associated with an increased frequency of pre-tumor lesions and their conversion to malignancy. In this context, loss of Norrin signalling in endothelial cells is associated with an accelerated transition to a pro-tumor stroma characterized by vascular permeability, inflammation and angiogenic remodelling. Accordingly, loss of Ndp significantly alters the stromal gene expression signature of established Ptch MB.
Norrin/Frizzled4 signalling in the preneoplastic niche blocks medulloblastoma initiation.
Specimen part
View SamplesThe meningeal space is occupied by a diverse repertoire of innate and adaptive immune cells. CNS injury elicits a rapid immune response that affects neuronal survival and recovery, but the role of meningeal inflammation in CNS injury remains poorly understood. Here we describe group 2 innate lymphoid cells (ILC2s) as a novel cell type resident in the healthy meninges that is activated following CNS injury. ILC2s are present throughout the naïve mouse meninges, though are concentrated around the dural sinuses, and have a unique transcriptional profile relative to lung ILC2s. After spinal cord injury, meningeal ILC2s are activated in an IL-33 dependent manner, producing type 2 cytokines. Using RNAseq, we characterized the gene programs that underlie the ILC2 activation state. Finally, addition of wild type lung-derived ILC2s into the meningeal space of IL-33R-/- animals improves recovery following spinal cord injury. These data characterize ILC2s as a novel meningeal cell type that responds to and functionally affects outcome after spinal cord injury, and could lead to new therapeutic insights for CNS injury or other neuroinflammatory conditions. Overall design: ILC2s were isolated from 10 week C57/Bl6 mice with and without spinal cord injury (1 day post injury). 5 mice were pooled per group, with meninges dissected, digested, and FACs sorted (CD45+/DAPI-/Lin–/St2+/Thy1+) directly into RNA lysis buffer.
Characterization of meningeal type 2 innate lymphocytes and their response to CNS injury.
Age, Specimen part, Cell line, Subject
View SamplesHuman cytomegalovirus induces a pro-inflammatory monocyte following infection. To begin to address how HCMV induces these rapid changes in infected monocytes, we examined the transcriptome of infected monocytes. Global transcriptional profiling using cDNA microarrays revealed a significant number of pro-inflammatory genes were upregulated within 4 hours post infection.
Transcriptome analysis reveals human cytomegalovirus reprograms monocyte differentiation toward an M1 macrophage.
Specimen part
View SamplesAdult zebrafish are capable of regenerating cardiac tissue following ventricular resection within 30 days. We profiled both small RNA and mRNA expression in uninjured (0dpa), 1, 3, 7, 14, 21 and 30 days post amputation to study biological processes orchestrate each stage of regeneration. Overall design: Small and mRNA gene expression profiling during 0, 1, 3, 7, 14, 21 and 30 days post ventricular resection.
RegenDbase: a comparative database of noncoding RNA regulation of tissue regeneration circuits across multiple taxa.
Specimen part, Cell line, Subject
View SamplesThe chronological lifespan (CLS) of Saccharomyces cerevisiae is defined as the number days that non-dividing cells remain viable, typically in stationary phase cultures or in water. CLS is extended by restricting glucose in the starting cultures, and is considered a form of caloric restriction (CR). Through a previous genetic screen our lab determined that deleting components of the de novo purine biosynthesis pathway also significantly increased CLS. Significant similarities in gene expression profiles between calorie restricted WT cells and a non-restricted ade4 mutant suggested the possibility of common gene expression biomarkers of all chronologically long lived cells that could also provide insights into general mechanisms of lifespan extension. We have identified additional growth conditions that extend CLS of WT cells, including supplementation of the media with isonicotinamide (INAM), a known sirtuin activator, or by supplementation with a concentrate collected from the expired media of a calorie restricted yeast culture, presumably due to an as yet unidentified longevity factor. Using these varied methods to extend CLS, we compared gene expression profiles in the aging cells (at day 8) to identify functionally relevant biomarkers of longevity. Nineteen genes were differentially regulated in all 4 of the long-lived populations relative to wild type. Of these 19 genes, viable haploid deletion mutants were available for 16 of them, and 12 were found to have a significant impact on CLS.
Functional genomic analysis reveals overlapping and distinct features of chronologically long-lived yeast populations.
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View SamplesThis study demonstrates quantitative and qualitative differences between type I IFN signatures in autoimmunity and viral infection using purified CD4pos T cells and CD16pos- and CD16neg-monocyte subsets. We were able to discriminate between cell-specific viral response signatures and the pathogenically amplified IFN signatures observed in autoimmunity. The differences were of both a qualitative and quantitative nature, as the signatures in the patients with SLE were characterized by much more complexly compiled gene patterns with increased absolute gene expression levels.
Cell-specific type I IFN signatures in autoimmunity and viral infection: what makes the difference?
Specimen part
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