Oligodendrocytes (OLs) and myelin are critical for normal brain function and they have been implicated in neurodegeneration. Human neuroimaging studies have demonstrated that alterations in axons and myelin occur early in Alzheimer's Disease (AD) course. However, the molecular mechanism underlying the role of OLs in AD remains largely unknown. In this study, we systematically interrogated OL-enriched gene networks constructed from large-scale genomic, transcriptomic, and proteomic data in human AD postmortem brain samples. These robust OL networks were highly enriched for genes associated with AD risk variants, including BIN1. We corroborated the structure of the AD OL coexpression and gene-gene interaction networks through ablation of genes identified as key drivers of the networks, including UGT8, CNP, MYRF, PLP1, NPC1, and NDGR1. Perturbations of these key drivers not only caused dysregulation in their associated network neighborhoods, but also mimicked pathways of gene expression dysregulation seen in human AD postmortem brain samples. In particular, the OL subnetwork controlled by the AD risk gene PSEN1 was strongly dysregulated in AD, suggesting a potential role of PSEN1 in disrupting the myelination pathway towards the onset of AD. In summary, this study built and systematically validated the first comprehensive molecular blueprint of OL dysregulation in AD, and identified key OL- and myelination-related genes and networks as potential candidate targets for the future development of AD therapies. Overall design: The mouse knockout models have been previously described for each of Ugt8 (Coetzee et al., 1996), Cnp (Lappe-Siefke et al., 2003), and Plp1 (Klugmann et al., 1997). For each of the two conditions studied (control and homozygous knockout mice), five mice of either sex were sacrificed at postnatal day 20 and brains were flashed-frozen until analysis. The frontal cortex (FC) and cerebellum (CBM) were dissected out and individually processed. RNA was isolated using Trizol reagent and processed using Ribo-Zero rRNA removal. RNA-sequencing was performed using the Illumina HiSeq2000 with 100 nucleotide paired-end reads. RNA-sequencing reads were mapped to the mouse genome (mm10, UCSC assembly) using Bowtie (version 2.2.3.0), TopHat (version 2.0.11), and SamTools (version 0.1.19.0) using a read length of 100. Reads were converted to counts at the gene level using HTSeq on the BAM files from TopHat2 using the UCSC known genes data set.
Multiscale network modeling of oligodendrocytes reveals molecular components of myelin dysregulation in Alzheimer's disease.
Specimen part, Subject
View SamplesQuiescent stem cells of glioblastoma (GBM), a malignant primary brain tumor, are potential sources for recurrence after therapy. However, the gene expression program underlying the physiology of GBM stem cells remains unclear. We have isolated quiescent GBM cells by engineering them with a knock-in H2B-GFP proliferation reporter and expanding them in a 3D tumor organoid model that mimics tumor heterogeneity. H2B-GFP label retaining quiescent cells were subjected to stem cell assays and RNA-Seq gene expression analysis. While quiescent GBM cells were similar in clonal culture assays to their proliferative counterparts, they displayed higher therapy resistance. Interestingly, quiescent GBM cells upregulated epithelial-mesenchymal transition (EMT) genes and genes of extracellular matrix components. Our findings connect quiescent GBM cells with an EMT-like shift, possibly explaining how GBM stem cells achieve high therapy resistance and invasiveness, and suggest new targets to abrogate GBM. Overall design: Glioblastoma cancer cells in 3D organoid culture were pulsed for 2 weeks with H2B-GFP, then chased either 2 or 4 weeks. Label-retaining GFP-high cells (quiescent) were separated from bulk population, and both populations were analyzed by RNA-Seq.
Gene signatures of quiescent glioblastoma cells reveal mesenchymal shift and interactions with niche microenvironment.
Specimen part, Subject
View SamplesRearrangements involving the NUP98 gene resulting in fusions to several partner genes occur in acute myeloid leukemia and myelodysplastic syndromes. This study demonstrates that the second FG repeat domain of the NUP98 moiety of the NUP98-HOXA9 fusion protein is important for its cell immortalization and leukemogenesis activities. We demonstrate that NUP98-HOXA9 interacts with MLL via this FG repeat domain and that, in the absence of MLL, NUP98-HOXA9-induced cell immortalization and leukemogenesis are severely inhibited. Molecular analyses indicate that MLL is important for the recruitment of NUP98-HOXA9 to the HOXA locus and for NUP98-HOXA9-induced HOXA gene expression. Our data indicate that MLL is crucial for NUP98-HOXA9 leukemia initiation.
MLL is essential for NUP98-HOXA9-induced leukemia.
No sample metadata fields
View SamplesA GFP-expressing recombinant A/Puerto Rico/8/1934 influenza virus was used to infect C57BL/6 wild type mice and on day 3 post infection, lung alveolar epithelial cells (AEC) were isolated and sorted based on GFP expression. GFP+ AEC represent the infected AEC and GFP- AEC represent the bystander AEC. AEC were also sorted from uninfected mice to serve as controls. Overall design: AEC from infected mice were pooled to make three (3) infected GFP+ AEC replicates for sequencing. Five (5) bystander GFP- replicates and five (5) uninfected AEC replicates were also isolated for sequencing
Transcriptome Analysis of Infected and Bystander Type 2 Alveolar Epithelial Cells during Influenza A Virus Infection Reveals <i>In Vivo</i> Wnt Pathway Downregulation.
Specimen part, Subject, Time
View SamplesRegeneration of fragmented Drosophila imaginal discs occurs in an epimorphic manner, involving local cell proliferation at the wound site. Following disc fragmentation, cells at the wound site activate a restoration program through wound healing, regenerative cell proliferation and repatterning of the tissue. However, the interplay of signaling cascades, driving these early reprogramming steps, is not well understood. Here we profiled the transcriptome of regenerating cells in the early phase within twenty-four hours after wounding. We found that JAK/STAT signaling becomes activated at the wound site and promotes regenerative cell proliferation in cooperation with Wingless (Wg) signaling. In addition, we demonstrated that the expression of Drosophila insulin-like peptide 8 (dilp8), which encodes a paracrine peptide to delay the onset of pupariation, is controlled by JAK/STAT signaling in early regenerating discs. Our findings suggest that JAK/STAT signaling plays a pivotal role in coordinating regenerative disc growth with organismal developmental timing.
During Drosophila disc regeneration, JAK/STAT coordinates cell proliferation with Dilp8-mediated developmental delay.
Sex, Specimen part, Treatment
View SamplesGlioblastomas show heterogeneous histological features. These distinct phenotypic states are thought to be associated with the presence of glioma stem cells (GSCs), which are highly tumorigenic and self-renewing sub-population of tumor cells that have different functional characteristics. To investigate gene expression including lncRNA (long non-coding RNA) in GSC, we have performed high-throughput RNA-sequencing (RNA-seq) experiment using Illumina GAIIx. Overall design: Profiles of gene expression including lncRNA in GSC were generated by RNA-seq using Illumina GAIIx.
Targeting the Notch-regulated non-coding RNA TUG1 for glioma treatment.
No sample metadata fields
View SamplesMicroRNA-155 (miR-155) is upregulated in primary effector CD8 T cells but is expressed at low amounts in nave cells. Anti-viral CD8 T cell responses and viral clearance were impaired in miR-155 deficient (bic-/-) mice, and this defect was intrinsic to CD8 T cells, as adoptively transferred bic-/- CD8 T cells generated greatly reduced primary and memory responses during infection. To understand the mechanism by which miR-155 regulates CD8 T cell activation, we analyzed the gene expression profiles of naive and in vitro activated wild-type and bic-/- CD8 T cells.
The microRNA miR-155 controls CD8(+) T cell responses by regulating interferon signaling.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative genomics of gene and metabolic regulation by estrogen receptors α and β, and their coregulators.
Specimen part, Cell line
View SamplesThe closely related transcription factors (TFs), estrogen receptors ER and ER, regulate divergent gene expression programs and proliferative outcomes in breast cancer. Utilizing MCF-7 breast cancer cells with ER, ER, or both receptors as a model system to define the basis of differing response specification by related TFs, we show that these TFs and their key coregulators, SRC3 and RIP140, generate overlapping as well as unique chromatin-binding and transcription-regulating modules.
Integrative genomics of gene and metabolic regulation by estrogen receptors α and β, and their coregulators.
Specimen part, Cell line
View SamplesHuntingtons disease (HD) is a neurodegenerative disorder that is associated with the deposition of proteinaceous aggregates in the brains of HD patients and mouse models. Previous studies have suggested that wide-scale disruption of protein homeostasis occurs in protein folding diseases. Protein homeostasis can be maintained by activation of the heat shock response (HSR) via the transcription factor heat shock factor 1 (HSF1), the pharmacological activation of which can be achieved by Hsp90 inhibition and has been demonstrated to be beneficial in cell and invertebrate models of HD. Whether the HSR is functional in HD and whether its activation has therapeutic potential in mammalian HD models is currently unknown. To address these issues, we used a novel, brain penetrant Hsp90 inhibitor to activate the HSR in brain after systemic administration. Microarrays, quantitative PCR and western blotting showed that the HSR becomes impaired with disease progression in two mouse models of HD and that this originates at the level of transcription.
Altered chromatin architecture underlies progressive impairment of the heat shock response in mouse models of Huntington disease.
Sex, Age, Specimen part, Treatment
View Samples