Myelination is essential for nervous system function. Schwann cells interact with neurons and with the basal lamina to sort and myelinate axons, using known receptors and signaling pathways. In contrast, the transcriptional control of axonal sorting and the role of mechano-transduction in myelination are largely unknown. Yap and Taz are effectors of the Hippo pathway that integrate chemical and mechanical signals in cells. Here, we describe a previously unknown role for the Hippo pathway in myelination. Using conditional mutagenesis in mice we show that Taz is required in Schwann cells for radial sorting and myelination. Yap is redundant with Taz as ablation of both Yap and Taz abolishes radial sorting. Yap/Taz regulate Schwann cell proliferation and transcription of basal lamina receptors, both necessary for proper radial sorting of axons, and subsequent myelination. These data link transcriptional effectors of the Hippo pathway and of mechanotransduction to myelin formation in Schwann cells. Overall design: 3 cKO and 3 control wild-type mice
YAP and TAZ control peripheral myelination and the expression of laminin receptors in Schwann cells.
Specimen part, Subject
View SamplesBackground: Severe septic syndromes deeply impair innate and adaptive immunity. While neutrophils represent the first line of defense against infection, little is known about their phenotype and functions during sepsis-induced immunosuppression. The objective of this study was thus to perform for the first time a global evaluation of neutrophil alterations in immunosuppressed septic patients based on phenotypic, functional and transcriptomic studies. In addition, the potential association of these parameters and deleterious outcomes was assessed.
Marked alterations of neutrophil functions during sepsis-induced immunosuppression.
Disease
View SamplesBariatric surgery is the most effective therapy of severe human obesity. It is associated with improvements in metabolic and non metabolic co-morbidities which are thought to be mediated by a decrease of adipose tissue inflammation. However, the molecular mechanisms behind these beneficial effects are poorly understood. We analyzed expression profiles in subcutaneous adipose tissue from 22 obese women before and 3 months after surgery using the RNA-seq technology. Of 15,972 detected genes, 1214 were differentially expressed after surgery. Upregulated genes were mostly involved in the basal cellular machinery. Downregulated genes were enriched in metabolic functions of adipose tissue. At baseline, we identified 26 modules of coexpressed genes. The four most stable modules reflected the innate and adaptive immune responses of adipose tissue, including a general signature of innate immune cells, an adaptive immune response elicited by T lymphocytes, a neutrophil-mediated inflammatory signature and an interferon-signaling pathway, respectively. After surgery, a few crucial molecules involved in chemotaxis and activation of immune cells were disconnected from their respective networks. These molecules may represent therapeutic targets against adipose inflammation. Overall design: mRNA sequencing of subcutaneous adipose tissue (SAT) samples from 22 obese women before and 3 months after bariatric surgery
Bariatric Surgery Induces Disruption in Inflammatory Signaling Pathways Mediated by Immune Cells in Adipose Tissue: A RNA-Seq Study.
No sample metadata fields
View SamplesWe assessed the impact of glucose transporter Glut2 gene inactivation in adult mouse liver (LG2KO mice). This suppressed hepatic glucose uptake but not glucose output. In the fasted state, expression of carbohydrate responsive element-binding protein (ChREBP) and its glycolytic and lipogenic target genes was abnormally elevated. Feeding, energy expenditure, and insulin sensitivity were identical in LG2KO and control mice. Glucose tolerance was normal early after Glut2 inactivation but intolerance developed at later time. This was caused by progressive impairment of glucose-stimulated insulin secretion even though beta-cell mass and insulin content remained normal. Liver transcript profiling revealed a coordinate down-regulation of cholesterol biosynthesis genes in LG2KO mice. This was associated with reduced hepatic cholesterol in fasted mice and a 30 percent reduction in bile acid production. We showed that chronic bile acids or FXR agonist treatment of primary islets increases glucose-stimulated insulin secretion, an effect not seen in islets from fxr-/- mice. Collectively, our data show that glucose sensing by the liver controls beta-cell glucose competence, through a mechanism that likely depends on bile acid production and action on beta-cells.
Hepatic glucose sensing is required to preserve β cell glucose competence.
Specimen part
View SamplesDiminishing potential to replace damaged tissues is a hallmark for ageing of somatic stem cells, but the mechanisms leading to ageing remain elusive. We present a proteome-wide atlas of age-associated alterations in human haematopoietic stem and progenitor cells (HPCs) along with five other cell types that constitute the bone marrow niche. For each, the abundance of a large fraction of the ~12,000 proteins identified was assessed in a cohort of healthy human subjects from different age. As the HPCs became older, pathways in central carbon metabolism exhibited features reminiscent of the Warburg effect where glycolytic intermediates are rerouted towards anabolism. Simultaneously, altered abundance of early regulators of HPC differentiation revealed a reduced functionality and a bias towards myeloid differentiation at the expense of lymphoid development. Ageing caused significant alterations in the bone marrow niche too, such as functionality of the pathways involved in HPC homing and lineage differentiation. The data represents a valuable resource for further in-depth mechanistic analyses, and for validation of knowledge gained from animal models. Overall design: RNA-seq samples extracted from human bone marrow, from 6 cell populations (HPC, LYM, MON, ERP, GRA, MSC). Technical replicates are included for each donor and cell type. Technical replicates were produced by making independent libraries from the same RNA.
Glycogen accumulation, central carbon metabolism, and aging of hematopoietic stem and progenitor cells.
Sex, Age, Specimen part, Subject
View SamplesThis study was performed to understand what controls the aggressivity of the pancreatic infiltrate during type-I diabetes development. We used the BDC2.5 transgenic mouse model. Samples were obtained at the age of onset of insultis. Depending on their genetic background, mice transgenic for the BDC2.5 T cell receptor present very different forms of insulitis. The NOD genetic background leads to a benign insulitis whereas the C57Bl/6-H2g7/g7 leads to an aggressive insulitis. We first studied how antigen-specific T cells are affected by these differences by obtaining the transcriptional profiles of BDC2.5 T cells from pancreas and pancreatic lymph nodes. We also compared the gene expression profiles of the entire leukocyte population present in the pancreatic lesion.
Natural killer cells distinguish innocuous and destructive forms of pancreatic islet autoimmunity.
Age, Specimen part
View SamplesThe development of high-throughput genomic technologies has revealed that a large fraction of the genomes of eukaryotes is associated with the expression of noncoding RNAs. One class of noncoding RNA, the cis-natural antisense transcripts (cis-NATs), are particularly interesting as they are at least partially complementary to the protein-coding mRNAs. Although most studies described cis-NATs involved in the regulation of transcription, a few reports have shown recently that cis-NATs can also regulate translation of the cognate sense coding genes in plants and mammals. In order to identify novel examples of translation regulator cis-NATs in Arabidopsis thaliana, we designed a high-throughput experiment based on polysome profiling and RNA-sequencing. Expression of cis-NATs and translation efficiency of the cognate coding mRNAs were measured in roots and shoots in response to various conditions, including phosphate deficiency and treatment with phytohormones. We identified several promising candidates, and validated a few of them experimentally, in Arabidopsis thaliana transgenic lines over-expressing in trans the translation regulator candidate cis-NATs. Overall design: total RNA and polysomal RNA was sequenced from Arabidopsis thaliana whole seedlings grown in high or low pohsphate content, or from roots or shoots from seedlings treated or not with different phytohormones (Ctrl, IAA, ABA,MeJA and ACC). 3 biological replicates were analyzed for each of the 12 experimental conditions.
Prediction of regulatory long intergenic non-coding RNAs acting in trans through base-pairing interactions.
Specimen part, Treatment, Subject
View SamplesT2 progenies of two transgenic lines overexpressing ERF transcription factor WIN1 were grown on soil in parallel under identical conditions. mRNA was extracted from pooled leaves from multiple plants of each line for the microarray experiement.
WIN1, a transcriptional activator of epidermal wax accumulation in Arabidopsis.
No sample metadata fields
View SamplesThe molecular mechanism(s) leading to Purkinje neuron loss in the neurodegenerative disorder Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS) are limited by the complex morphology of this cell type. Purkinje neurons are notoriously difficult to isolate and maintain in culture presenting considerable difficultly to identify molecular changes in response to riboCGG repeat-containing mRNA that induces neurotoxicity in FXTAS. Several studies have uncovered a number of RNA binding proteins involved in translation that aberrantly interact with the toxic RNA; however, whether these interactions alter the translational profile of cells has not been investigated. Here we employ bacTRAP translational profiling to demonstrate that Purkinje neurons ectopically expressing 90 CGG repeats exhibit a dramatic change in their translational profile even prior to the onset of riboCGG-induced phenotypes. This approach identified nearly 500 transcripts that are differentially associated with ribosomes in r(CGG)90-expressing mice. Functional annotation cluster analysis revealed broad ontologies enriched in the r(CGG)90 list, including RNA binding and response to stress. Intriguingly, a transcript for the Tardbp gene, implicated in a number of other neurodegenerative disorders, exhibits altered association with ribosomes in the presence of r(CGG)90 repeats. We therefore tested and showed that reduced association of Tardbp mRNA with the ribosomes results in a loss of TDP-43 protein expression in r(CGG)90expressing Purkinje neurons. Furthermore, we showed that TDP-43 could modulate the rCGG repeat-mediated toxicity in a Drosophila model that we developed previously. These findings together suggest translational dysregulation may be an underlying mechanism of riboCGG-induced neurotoxicity and provide insight into the pathogenicity of FXTASBAC-trap studies of Purkinje cels in normal and mutant mice
CGG repeats in RNA modulate expression of TDP-43 in mouse and fly models of fragile X tremor ataxia syndrome.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Performance comparison of two microarray platforms to assess differential gene expression in human monocyte and macrophage cells.
Sex, Age, Specimen part
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