Host cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc Downstream-Reguated Gene 1 (NDRG1) limits productive HCV infection by inhibiting viral assembly. Interestingly, HCV infection down-regulates NDRG1 protein and mRNA expression. Loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by up-regulating MYC, which directly inhibits the transcription of NDRG1.
N-Myc Downstream-Regulated Gene 1 Restricts Hepatitis C Virus Propagation by Regulating Lipid Droplet Biogenesis and Viral Assembly.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesTo gain global insights into the role of the well-known repressive splicing regulator PTB we analyzed the consequences of PTB knockdown in HeLa cells using high-density oliogonucleotide splice-sensitive microarrays. The major class of identified PTB-regulated splicing event was PTB-repressed cassette exons, but there was also a substantial number of PTB-activated splicing events. PTB repressed and activated exons showed a distinct arrangement of motifs with pyrimidine-rich motif enrichment within and upstream of repressed exons, but downstream of activated exons. The N-terminal half of PTB was sufficient to activate splicing when recruited downstream of a PTB-activated exon. Moreover, insertion of an upstream pyrimidine tract was sufficient to convert a PTBactivated to a PTB-repressed exon. Our results demonstrate that PTB, an archetypal splicing repressor, has variable splicing activity that predictably depends upon its binding location with respect to target exons.
Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
Cell line
View SamplesDifferentiating erythroid cells execute a unique gene expression program that insures synthesis of the appropriate proteome at each stage of maturation. Standard expression microarrays provide important insight into erythroid gene expression, but cannot detect qualitative changes in transcript structure, mediated by RNA processing, that alter structure and function of encoded proteins. We analyzed stage-specific changes in the late erythroid transcriptome via use of high resolution microarrays that detect altered expression of individual exons. Ten differentiation-associated changes in erythroblast splicing patterns were identified, including the previously known activation of protein 4.1R exon 16 splicing. Six new alternative splicing switches involving enhanced inclusion of internal cassette exons were discovered, as well as three changes in use of alternative first exons. All of these erythroid stage-specific splicing events represent activated inclusion of authentic annotated exons, suggesting they represent an active regulatory process rather than a general loss of splicing fidelity. The observation that three of the regulated transcripts encode RNA binding proteins (SNRP70, HNRPLL, MBNL2) may indicate significant changes in the RNA processing machinery of late erythroblasts. Together these results support the existence of a regulated alternative pre-mRNA splicing program that is critical for late erythroid differentiation.
Alternative pre-mRNA splicing switches modulate gene expression in late erythropoiesis.
No sample metadata fields
View SamplesAlthough it is well established that the ovarian reserve diminishes with increasing age, and that a womans age is correlated to lower oocyte quality, the interplay of a diminished reserve and age on oocyte developmental competence is not clear. After maturation, oocytes are mostly transcriptionally quiescent, and developmental competence prior to embryonic genome activation (EGA) relies on maternal RNA and proteins. Age and ovarian reserve both affects oocyte developmental competence, however, their relative importance in this process are difficult to tease out, as ageing is accompanied by a decrease in ovarian reserve. Oocytes store large quantities of RNA, including several noncoding transcripts (ncRNAs) involved in early development transcription and translation modulation. Despite the central role of ncRNAs in maternal to zygote transition, no characterization of the ncRNA transcriptome in human oocytes has been reported. This study aims at identifying how the human oocyte transcriptome changes across reproductive ages and ovarian reserve levels, with the goal of identifying candidate markers of developmental competence, and to assess the independent relevance of age and ovarian reserve in the changes of the transcriptome
The transcriptome of human oocytes is related to age and ovarian reserve.
No sample metadata fields
View SamplesWe used RNA sequencing to characterize gene expression of dendritic cells from mouse lymph node that, based on LIPSTIC labeling, underwent interaction with CD4+ T cells. Overall design: Antigen pulsed dendritic cells (DCs) were transferred into recipient mice, followed by antigen specific CD4+ T cells. Forty-eight hours after T cell transfer, endogenous dendritic cells were isolated by facs sorting from mouse lymph node and analyzed based on their in vivo LIPSTIC labeling.
Monitoring T cell-dendritic cell interactions in vivo by intercellular enzymatic labelling.
Specimen part, Cell line, Subject
View SamplesInattention, impulsivity and hyperactivity are the primary behaviors associated with Attention Deficit / Hyperactivity Disorder (ADHD). Previous studies proved that peripheral blood gene expression signature could mirror central nervous system disease.
Correlations of gene expression with ratings of inattention and hyperactivity/impulsivity in Tourette syndrome: a pilot study.
Sex, Age, Specimen part
View SamplesLarge inter-individual variance has been observed in sensitivity to drugs. To comprehensively decipher the genetic contribution to these variations in drug susceptibility, we present a genome-wide model utilizing human lymphoblastoid cell lines from the International HapMap consortium, of which extensive genotypic information is available, to identify genetic variants that contribute to chemotherapeutic agent-induced cytotoxicity. Our model integrated genotype, gene expression and sensitivity of HapMap cell lines to drugs. Cell lines derived from 30 trios of European descent (CEU) and 30 trios of African descent (YRI) were utilized. Cell growth inhibition at increasing concentrations of etoposide for 72 h was determined using alamarBlue assay. Gene expression on 176 HapMap cell lines (87 CEU and 89 YRI) was determined using the Affymetrix GeneChip Human Exon 1.0ST Array. We evaluated associations between genotype and cytotoxicity, genotype and gene expression and correlated gene expression of the identified candidates with cytotoxicity. The analysis identified 63 genetic variants that contribute to etoposide-induced toxicity through their effect on gene expression. These include genes that may play a role in cancer (AGPAT2, IL1B and WNT5B) and genes not yet known to be associated with sensitivity to etoposide. This unbiased method can be used to elucidate genetic variants contributing to a wide range of cellular phenotypes induced by chemotherapeutic agents.
A genome-wide approach to identify genetic variants that contribute to etoposide-induced cytotoxicity.
Sex
View SamplesIn addition to the differences between populations in transcriptional and translational regulation of genes, alternative pre-mRNA splicing (AS) is also likely to play an important role in regulating gene expression and generating variation in mRNA and protein isoforms. Recently, the genetic contribution to transcript isoform variation has been reported in individuals of recent European descent. We report here results of an investigation of the differences in AS patterns between human populations. AS patterns in 176 HapMap lymphoblastoid cell lines derived from individuals of European and African ancestry were evaluated using the Affymetrix GeneChip Human Exon 1.0 ST Array. A variety of biological processes such as immune response and mRNA metabolic process were found to be enriched among the differentially spliced genes. The differentially spliced genes also include some involved in human diseases that have different prevalence or susceptibility between populations. The genetic contribution to the population differences in transcript isoform variation was then evaluated by a genome-wide association using the HapMap genotypic data on single nucleotide polymorphisms (SNPs). The results suggest that local and distant genetic variants account for a substantial fraction of the observed transcript isoform variation between human populations.
Identification of common genetic variants that account for transcript isoform variation between human populations.
Sex
View SamplesWe have undertaken a screen of mouse limb tendon cells in order to identify molecular pathways involved in tendon development. Mouse limb tendon cells were isolated based on Scleraxis (Scx) expression at different stages of development: E11.5, E12.5 and E14.5
Transcriptomic analysis of mouse limb tendon cells during development.
No sample metadata fields
View Samples