Notch1 signaling is absolutely essential for steady-state thymic lymphopoiesis, but the role of other Notch receptors, and their potential overlap with the function of Notch1, remains unclear. Here we show that like Notch1, Notch3 is differentially expressed by progenitor thymocytes, peaking at the DN3 progenitor stage. Using mice carrying a gene-trapped allele, we show that thymic cellularity is slightly reduced in the absence of Notch3, although progression through the defined sequence of TCR- development is normal, as are NKT and TCR cell production.
Nonoverlapping functions for Notch1 and Notch3 during murine steady-state thymic lymphopoiesis.
Sex, Age, Specimen part
View SamplesPurpose: The goals of this study are to elucidate the influence of integrin ß3 signaling on STAT1-dependnet gene expression in IFN?-treated HSCs. Methods: Wild type (WT) HSCs were cultured with or without IFN? and/or VN in the presence of stem cell factor (SCF) plus thrombopoietin (TPO). Subsequently, cultured HSC fraction (CD48- c-kit+ Sca-1+ Lineage-) were sorted, followed by mRNA sequence using Ion Proton (n>4). Moreover, to extract genes whose expression were changed via STAT1 in the presence of IFN?, mRNA profiles of STAT1-/- HSCs treated with or without IFN? were also generated by the same way. The sequence reads that passed quality filters were analyzed by CLC genomic workbench. Results: Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to the mouse genome (build mm10) with CLC genomic workbench. Indeed, hierarchical clustering analysis showed that IFN?-treated STAT1-/- HSCs was categorized to the group including Wt HSCs cultured in the absence of IFN? rather than HSCs treated with IFN?. Furthermore, gene set enrichment analysis (GSEA) showed that STAT1-dependent upregulated gene sets were significantly enriched within genes whose expression was enhanced in HSCs treated with VN and IFN?. In contrast, integrin ß3 signaling in the absence of IFN? appears to not influence the expression of IFN?/STAT1-dependent genes, as evidenced by the observation that VN treatment was statistically and significantly independent of the enrichment of gene sets that were both up-regulated by STAT1 Conclusions: Our study represents that STAT1 plays a central role in IFN?-mediated HSC responses and integrin ß3 signaling in HSCs promotes STAT1-dependent gene expression in the presence of IFN?. Overall design: After HSCs derived from wild type (WT) and STAT1-/- mice were treated with IFNg and/or vitronectin for 5 days, mRNA profiles were generated by deep sequencing using Ion Proton system (n>4).
Integrin αvβ3 enhances the suppressive effect of interferon-γ on hematopoietic stem cells.
Specimen part, Cell line, Subject
View SamplesThe mTOR (mammalian Target of Rapamycin) pathway is constitutively activated in Diffuse Large B-Cell Lymphoma (DLBCL). mTOR inhibition has been shown to have clinical activity in patients with DLBCL, although overall response rates remain low. We therefore evaluated differences in the transcriptome between DLBCL cell lines with differential sensitivity to the mTOR inhibitor Rapamycin, to (A) identify gene-expression patterns(GEP) capable of identifying sensitivity to Rapamycin, (B) understand the underlying mechanisms of resistance to Rapamycin in DLBCL and (C) identify bioactive molecules likely to synergize with mTOR inhibitors. Using Affymetrix HuGene ST 1.0 microarrays, we were able to identify a gene expression signature capable of accurately predicting sensitivity and resistance to Rapamycin in DLBCL cell lines. Pathway analysis identified the serine/threonine kinase Akt as central to the differentially-expressed gene network. Connectivity mapping of our datasets identified compounds targeting the AKT pathway with a high likelihood of reversing the GEP associated with resistance to Rapamycin. Specifically, we evaluated the HIV protease inhibitor (PI) Nelfinavir, which is known to have anti-cancer and Akt-inhibitory properties, as well as the small molecule Akt inhibitor MK-2206, for their potential to synergize with to Rapamycin in DLBCL. Nelfinavir and MK-2206 caused profound inhibition of cell viability in combination with Rapamycin in DLBCL cell lines. Low nanomolar concentrations of Rapamycin inhibited phosphorylation of Akt and also downstream targets of activated mTOR when used in combination with these Akt inhibitors. These findings have the potential to significantly improve patient selection for mTOR inhibitor therapy, and to improve rates and depths of response. More broadly, they support the use of global RNA expression and connectivity mapping to improve patient selection and identify synergistic drug combinations for cancer therapy.
Akt inhibitors MK-2206 and nelfinavir overcome mTOR inhibitor resistance in diffuse large B-cell lymphoma.
Cell line
View SamplesExercise attenuates the development of chronic non-communicable diseases (NCDs). Gene signaling pathway analysis offers an opportunity to discover if electrically induced muscle exercise regulates key pathways among people living with spinal cord injury (SCI). We examined short-term and long-term durations of electrically induced skeletal muscle exercise on complex gene signaling pathways, specific gene regulation, and epigenetic tagging of PGC1a, a major transcription factor in skeletal muscle of men with SCI. After short or long-term electrically induced exercise training, participants underwent biopsies of the trained and untrained muscles. RNA was hybridized to an exon microarray and analyzed using a gene set enrichment analysis. We discovered that long-term exercise training regulated the Reactome gene sets for Metabolism (38 gene sets), Cell Cycle (36 gene sets), Disease (27 gene sets), Gene Expression and Transcription (22 gene sets), Organelle Biogenesis (4 gene sets), Cellular Response to Stimuli (8 gene sets), Immune System (8 gene sets), Vesicle Mediated Transport (4 gene sets), and Transport of Small Molecules (3 gene sets). Specific gene expression included: Oxidative catabolism of glucose including PDHB (p<0.001), PDHX (p<0.001), MPC1 (p<0.009), and MPC2 (p<0.007); Oxidative phosphorylation genes including SDHA (p<0.006), SDHB (p<0.001), NDUFB1 (p<0.002), NDUFA2 (p<0.001); Transcription Genes including PGC1α (p<0.030) and PRKAB2 (p<0.011); Hypertrophy gene MSTN (p<0.001); and the Myokine generating FNDC5 gene (p<0.008). Long-term electrically induced exercise de-methylated the major transcription factor, PGC1a. Taken together, these findings support that long term electrically induced muscle activity regulates key pathways associated with muscle health and systemic metabolism.
Impact of short- and long-term electrically induced muscle exercise on gene signaling pathways, gene expression, and PGC1a methylation in men with spinal cord injury.
Sex, Specimen part, Disease
View SamplesExpression of the SS18/SYT-SSX fusion protein is believed to underlie the pathogenesis of synovial sarcoma (SS). Recent evidence suggests that deregulation of the Wnt pathway may play an important role in SS but the mechanisms whereby SS18-SSX might affect Wnt signaling remain to be elucidated. Here, we show that SS18/SSX tightly regulates the elevated expression of the key Wnt target AXIN2 in primary SS. SS18-SSX is shown to interact with TCF/LEF, TLE and HDAC but not -catenin in vivo and to induce Wnt target gene expression by forming a complex containing promoter-bound TCF/LEF and HDAC but lacking -catenin. Our observations provide a tumor-specific mechanistic basis for Wnt target gene induction in SS that can occur in the absence of Wnt ligand stimulation.
The fusion protein SS18-SSX1 employs core Wnt pathway transcription factors to induce a partial Wnt signature in synovial sarcoma.
Cell line
View SamplesThe molecular mechanisms of neurogenic fate determination are of particular importance in light of the need to regenerate neurons. However the molecular logic of neurogenic fate determination is still ill understood, even though some key transcription factors have been implicated. Here we describe how one of these, the transcription factor Pax6, regulates adult neurogenesis by initiating a cross-regulatory network of 3 transcription factors executing neuronal fate and regulating genes required for neuronal differentiation. This network is initiated and driven to sufficiently high expression levels by the transcription factor Pax6 in close interaction with Brg1-containing SWI/SNF chromatin remodeling factors.
The BAF complex interacts with Pax6 in adult neural progenitors to establish a neurogenic cross-regulatory transcriptional network.
Sex, Age, Specimen part
View SamplesInteraction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them.
Spatial mapping of thymic stromal microenvironments reveals unique features influencing T lymphoid differentiation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cell identity regulators link development and stress responses in the Arabidopsis root.
Age, Specimen part, Treatment
View SamplesWe used a novel approach to study the acute effect of three physiologic stressors (active contractions, vibration, and systemic heat stress) in human skeletal muscle. Three hours after the completion of a dose of physiologic stress, we sampled the soleus (contraction and vibration) or vastus lateralis (heat) muscle and developed a unique gene expression signature for each stressor. We discovered repetitive active muscle contractions up regulated metabolic transcription factors NR4A3 (12.45 fold change), PGC-1 (5.46 fold change), and ABRA (5.98 fold change); and repressed MSTN (0.56 fold change). Heat stress repressed PGC-1 (0.74 fold change); while vibration induced FOXK2 (2.36 fold change). Vibration similarly caused a down regulation of MSTN (0.74 fold change), but to a lesser extent than active muscle contraction. Vibration induced FOXK2 while heat stress repressed PGC-1 (0.74 fold change) and ANKRD1 genes (0.51 fold change). These findings support a distinct gene regulation in response to heat stress, vibration, and muscle contractions. Understanding these responses may assist in developing regenerative rehabilitation interventions to improve muscle cell development, growth, and repair.
Distinct Skeletal Muscle Gene Regulation from Active Contraction, Passive Vibration, and Whole Body Heat Stress in Humans.
Sex, Specimen part
View SamplesCell-type specific transcriptional profiles were generated by FACS (Fluorescence Activated Cell Sorting) sorting of roots that express cell-type specific GFP-reporters. Five different GFP-reporter lines were used. FACS cell populations were isolated from roots grown under standard pH (pH 5.7) or roots that had been transfered to low pH (pH 4.6) media for 24 hours.
Cell identity regulators link development and stress responses in the Arabidopsis root.
Specimen part
View Samples