Human cytomegalovirus (hCMV) is a highly prevalent pathogen that, upon primary infection, establishes life-long persistence in all infected individuals. Acute hCMV infections cause a variety of diseases in humans with developmental or acquired immune deficits. In addition, persistent hCMV infection may contribute to various chronic disease conditions even in immunologically normal people. The pathogenesis of hCMV disease has been frequently linked to inflammatory host immune responses triggered by virus-infected cells. Moreover, hCMV infection activates numerous host genes many of which encode pro-inflammatory proteins. However, little is known about the relative contributions of individual viral gene products to these changes in cellular transcription. We systematically analyzed the effects of the hCMV 72-kDa immediate-early 1 (IE1) protein, a major transcriptional activator and antagonist of type I interferon (IFN) signaling, on the human transcriptome. Following expression under conditions closely mimicking the situation during productive infection, IE1 elicits a global type II IFN-like host cell response. This response is dominated by the selective up-regulation of immune stimulatory genes normally controlled by IFN-gamma and includes the synthesis and secretion of pro-inflammatory chemokines. IE1-mediated induction of IFN-stimulated genes strictly depends on tyrosine-phosphorylated signal transducer and activator of transcription 1 (STAT1) and correlates with the nuclear accumulation and sequence-specific binding of STAT1 to IFN-gamma-responsive promoters. However, neither synthesis nor secretion of IFN-gamma or other IFNs seems to be required for the IE1-dependent effects on cellular gene expression. Our results demonstrate that a single hCMV protein can trigger a pro-inflammatory host transcriptional response via an unexpected STAT1-dependent but IFN-independent mechanism and identify IE1 as a candidate determinant of hCMV pathogenicity.
Human cytomegalovirus IE1 protein elicits a type II interferon-like host cell response that depends on activated STAT1 but not interferon-γ.
Specimen part, Cell line
View SamplesSummary: Spinal cord injury (SCI) is a damage to the spinal cord induced by trauma or desease resulting in a loss of mobility or feeling. SCI is characterized by a primary mechanical injury followed by a secondary injury in which several molecular events are altered in the spinal cord often resulting in loss of neuronal function.
Gene profiling in spinal cord injury shows role of cell cycle in neuronal death.
No sample metadata fields
View SamplesDrosophila melanogaster neural stem cells (neuroblasts [NBs]) divide asymmetrically by differentially segregating protein determinants into their daughter cells. Although the machinery for asymmetric protein segregation is well understood, the events that reprogram one of the two daughter cells toward terminal differentiation are less clear. In this study, we use time-resolved transcriptional profiling to identify the earliest transcriptional differences between the daughter cells on their way toward distinct fates. By screening for coregulated protein complexes, we identify vacuolar-type H+–ATPase (v-ATPase) among the first and most significantly down-regulated complexes in differentiating daughter cells. We show that v-ATPase is essential for NB growth and persistent activity of the Notch signaling pathway. Our data suggest that v-ATPase and Notch form a regulatory loop that acts in multiple stem cell lineages both during nervous system development and in the adult gut. We provide a unique resource for investigating neural stem cell biology and demonstrate that cell fate changes can be induced by transcriptional regulation of basic, cell-essential pathways. Overall design: Comparison of transcriptomes of wild-type type I NBs and GMCs of different ages (1.5h, 3h or 5h old) isolated by FACS from Drosophila melanogaster larval brains.
Time-resolved transcriptomics in neural stem cells identifies a v-ATPase/Notch regulatory loop.
Specimen part, Subject
View SamplesOrganoids derived from human pluripotent stem cells recapitulate the early three-dimensional organization of human brain, but whether they establish the epigenomic and transcriptional programs essential for brain development is unknown. We compared epigenomic and gene regulatory features in cerebral organoids and human fetal brain, using genome-wide, base resolution DNA methylome and transcriptome sequencing. Transcriptomic dynamics in organoids faithfully modeled gene expression trajectories in early-to-mid human fetal brains. We found that early non-CG methylation accumulation at super-enhancers in both fetal brain and organoids marks forthcoming transcriptional repression in the fully developed brain. 74% of 35,627 demethylated regions identified during organoid differentiation overlapped with fetal brain regulatory elements. Interestingly, pericentromeric repeats showed widespread demethylation in multiple types of in vitro human neural differentiation models but not in fetal brain. Our study reveals that organoids recapitulate many epigenomic features of mid-fetal human brain and also identified novel non-CG methylation signatures of brain development. Overall design: MethylC-seq and RNA-seq of Cerebral Organoids differentiation
Cerebral Organoids Recapitulate Epigenomic Signatures of the Human Fetal Brain.
No sample metadata fields
View SamplesAblation of tetraspanin protein TSPAN12 from human MDA-MB-231 cells significantly decreased primary tumor xenograft growth, while increasing tumor apoptosis. Furthermore, TSPAN12 removal markedly enhanced tumor-endothelial interactions and increased metastasis to mouse lungs. TSPAN12 removal from human MDA-MB-231 cells also caused diminished association between FZD4 (a key canonical Wnt pathway receptor) and its co-receptor LRP5. The result likely explains substantially enhanced proteosomal degradation of -catenin, a key effecter of canonical Wnt signalling. Consistent with disrupted canonical Wnt signaling, TSPAN12 ablation altered expression of LRP5, Naked 1 and 2, DVL2, DVL3, Axin 1 and GSK3 proteins. TSPAN12 ablation also altered expression of several genes regulated by -catenin (e.g. CCNA1, CCNE2, WISP1, ID4, SFN, ME1) that may help to explain altered tumor growth and metastasis. In conclusion, these results provide the first evidence for TSPAN12 playing a role in supporting primary tumor growth and suppressing metastasis. TSPAN12 appears to function by stabilizing FZD4-LRP5 association, in support of canonical Wnt-pathway signaling, leading to enhanced -catenin expression and function.
Tetraspanin TSPAN12 regulates tumor growth and metastasis and inhibits β-catenin degradation.
No sample metadata fields
View SamplesThe TRIM-NHL protein Brain tumor (Brat) acts as a tumor suppressor in the Drosophila brain, but how it suppresses tumor formation is not completely understood. Here, we combine temperature controlled brat RNAi with transcriptome analysis to identify the immediate brat targets in Drosophila neuroblasts. Besides the known target Deadpan (Dpn), our experiments identify the transcription factor Zelda (Zld) as a critical target of brat. Our data show that Zld is expressed in neuroblasts and required to allow re-expression of Dpn in transit amplifying intermediate neural progenitors. Upon neuroblast division, Brat is enriched in one daughter cell where its NHL domain directly binds to specific motifs in the 3'UTR of dpn and zld mRNA to mediate their degradation. In brat mutants, both Dpn and Zld continue to be expressed, but inhibition of either transcription factor prevents tumorigenesis. Our genetic and biochemical data indicate that Dpn inhibition requires higher Brat levels than Zld inhibition and suggest a model where stepwise post-transcriptional inhibition of distinct factors ensures sequential generation of fates in a stem cell lineage. Overall design: Comparison of transcriptomes of Drosophila melanogaster control and brat RNAi larval brain type II neural stem cell lineages.
The tumor suppressor Brat controls neuronal stem cell lineages by inhibiting Deadpan and Zelda.
Specimen part, Subject
View SamplesIntroduction of brain tumor-relevant genetic aberrations initiates different subtypes of brain tumor-like neoplasms in cerebral organoids Overall design: Comparison of abundances (TPM) from different brain tumor organoid groups
Author Correction: Genetically engineered cerebral organoids model brain tumor formation.
Specimen part, Subject
View SamplesIntroduction of brain tumor-relevant genetic aberrations initiates different subtypes of brain tumor-like neoplasms in cerebral organoids Overall design: Comparison of transcriptomes from different brain tumor organoid groups
Author Correction: Genetically engineered cerebral organoids model brain tumor formation.
Specimen part, Subject
View SamplesGenome-wide transcriptome analyses have allowed for systems- level insights into gene regulatory networks. Due to the limited depth of quantitative proteomics, however, our understanding of post-transcriptional gene regulation and its effects on protein complex stoichiometry are lagging behind. Here, we employ deep sequencing and iTRAQ technology to determine transcript and protein expression changes of a Drosophila brain tumour model at near genome-wide resolution. In total, we quantify more than 6,200 tissue-specific proteins, corresponding to about 70% of all transcribed protein-coding genes. Using our integrated data set, we demonstrate that post-transcriptional gene regulation varies considerably with biological function and is surprisingly high for genes regulating transcription. We combine our quantitative data with protein-protein interaction data and show that post-transcriptional mechanisms significantly enhance co-regulation of protein complex subunits beyond transcriptional co-regulation. Interestingly, our results suggest that only about 11% of the annotated Drosophila protein complexes are co-regulated in the brain. Finally, we refine the composition of some of these core protein complexes by analysing the co-regulation of potential subunits. Our comprehensive transcriptome and proteome data provide a rich resource for quantitative biology and offer novel insights into understanding post- transcriptional gene regulation in a tumour model. Overall design: Transcriptomes of 1-3 day old adult female Drosophila melanogaster heads of control and brat mutant were generated by deep sequencing, in triplicate, using Illumina GAIIx.
Transcriptome and proteome quantification of a tumor model provides novel insights into post-transcriptional gene regulation.
Subject
View SamplesEngineered brain organoids (enCORs) exhibit reproducible neural differentiation and forebrain regionalization. Overall design: Comparison of transcriptomes from bioengineered micropatterned enCORs and spheroids at 20 days and 60 days
Guided self-organization and cortical plate formation in human brain organoids.
Specimen part, Subject, Time
View Samples