Design: Persistent latently infected CD4+ T cells represent a major obstacle to HIV eradication. Histone deacetylase inhibitors (HDACis) are a promising activation therapy in a shock and kill strategy. However, off-target effects of HDACis on host gene expression are poorly understood in primary cells of the immune system. We hypothesized that HDACi-modulated genes would be best identified with a dose response analysis. Methods: Resting primary CD4+ T cells were treated with increasing concentrations (0.34, 1, 3, or 10 M) of the HDACi, suberoylanilide hydroxamic acid (SAHA), for 24 hours and then subjected to microarray gene expression analysis. Genes with dose-correlated expression were identified with a likelihood ratio test using Isogene GX and a subset of these genes with a consistent trend of up or downregulation at each dose of SAHA were identified as dose-responsive. Histone modifications were characterized in promoter regions of the top 6 SAHA dose-responsive genes by RT-qPCR analysis of immunopreciptated chromatin (ChIP). Results: A large number of genes were shown to be up (N=657) or down (N=725) regulated by SAHA in a dose-responsive manner (FDR p-value < 0.05 and fold change |2|). Several of these genes (CTNNAL1, DPEP2, H1F0, IRGM, PHF15, and SELL) are potential in vivo biomarkers of SAHA activity. SAHA dose-responsive gene categories included transcription factors, HIV restriction factors, histone methyltransferases, and host proteins that interact with HIV proteins or the HIV LTR. Pathway analysis suggested net downregulation of T cell activation with increasing SAHA dose. Histone acetylation was not correlated with host expression, but plausible alternative mechanisms for SAHA-modulated expression were identified. Conclusions: Numerous host genes in CD4+ T cells are modulated by SAHA in a dose-responsive manner, including genes that may negatively influence HIV activation from latency. Our study suggests that SAHA influences gene expression through a confluence of several mechanisms, including histone acetylation, histone methylation, and altered expression and activity of transcription factors.
Dose-responsive gene expression in suberoylanilide hydroxamic acid-treated resting CD4+ T cells.
Specimen part, Subject
View SamplesThe patterning of the facial midline involves early specification of neural crest cells to form skeletal tissues that support the upper jaw . In order to understand the molecular mechanisms involved we have taken advantage of a beak duplication model developed in the chicken embryo. Here we can induce the transformation of the side of the beak into a second midline that is easily identifiable by the formation of a supernumerary egg tooth. The phenotype is induced by implanting two microscopic beads, one soaked in retinoic acid and the other soaked in Noggin into the side of the head of the chicken embryo. Here we use microarrays to profile expression of maxillary mesenchyme 16h after placing the beads. A subset of genes were validated using in situ hybridization and QPCR. The aims of the study are to test the function of these genes using retroviral transgenesis, knockdown with morpholinos or expression of secreted proteins and their application to the embryo.
Identification and functional analysis of novel facial patterning genes in the duplicated beak chicken embryo.
Specimen part, Treatment
View SamplesThe face is one of the three regions most frequently affected by congenital defects in humans. In order to understand the molecular mechanisms involved it is necessary to have a more complete picture of gene expression in the embryo. Here we use microarrays to profile expression in chicken facial prominences, post neural crest migration and prior to differentiation of mesenchymal cells. Chip-wide analysis revealed that maxillary and mandibular prominences had similar expression profiles while the frontonasal mass chips were distinct. Of the 3094 genes that were differentially expressed in one or more regions of the face, a group of 56 genes was subsequently validated with quantitative PCR and a subset examined with in situ hybridization. Microarrays trends were consistent with the QPCR data for the majority of genes (81%). On the basis of QPCR and microarray data, groups of genes that characterize each of the facial prominences can be determined.
Whole genome microarray analysis of chicken embryo facial prominences.
Specimen part
View SamplesWe found that the core spliceosomal proteins RBM17, U2SURP and CHERP form a protein complex regulating alternative splicing and expression of a whole network of RNA binding proteins Overall design: RNA sequencing of triplicate RNA samples from HEK293 cells treated with siRNAs against RBM17, U2SURP , CHERP or SCRAMBLE sequence
RBM17 Interacts with U2SURP and CHERP to Regulate Expression and Splicing of RNA-Processing Proteins.
Cell line, Subject
View SamplesRegulation of mRNA stability by RNA-protein interactions contributes significantly to quantitative aspects of gene expression. We have identified potential mRNA targets of the AU-rich element binding protein AUF1. Myc-tagged AUF1 p42 was induced in mouse NIH-3T3 cells and RNA-protein complexes isolated using anti-myc tag antibody beads. Bound mRNAs were analyzed with Affymetrix microarrays. We have identified 508 potential target mRNAs that were at least 3-fold enriched compared to control cells without myc-AUF1. 22.3% of the enriched mRNAs had an AU-rich cluster in the ARED Organism database, against 16.3% of non-enriched control mRNAs. The enrichment towards AU-rich elements was also visible by AREScore with an average value of 5.2 in the enriched mRNAs versus 4.2 in the control group. Yet, many mRNAs were enriched without a high ARE score suggesting that AUF1 has a broader binding spectrum than standard AUUUA repeats. AUF1 did not preferentially bind to unstable mRNAs. Still, some enriched mRNAs were highly unstable, as those of TNFSF11 (known as RANKL), KLF10, HES1, CCNT2, SMAD6, and BCL6. We have mapped some of the instability determinants. HES1 mRNA appeared to have a coding region determinant. Detailed analysis of the RANKL and BCL6 3UTR revealed for both that full instability required two elements, which are conserved in evolution. In RANKL mRNA both elements are AU-rich and separated by 30 bases, while in BCL6 mRNA one is AU-rich and 60 bases from a non AU-rich element that potentially forms a stem-loop structure.
Short-lived AUF1 p42-binding mRNAs of RANKL and BCL6 have two distinct instability elements each.
Cell line
View SamplesWe observed robust overexpression of type I interferon (IFN)inducible genes and genomic signatures that indicate T cell and dendritic cell infiltration in lesional skin. Up-regulation of mRNAs for IFN-a subtypes was observed in lesional skin compared with nonlesional skin. Enrichment of mature dendritic cells and 2 type I IFNinducible proteins, STAT1 and ISG15, were observed in the majority of lesional skin biopsies. Concordant overexpression of IFN-c and TNF-ainducible gene signatures occurred at the same disease sites.
Type I interferon: potential therapeutic target for psoriasis?
Disease
View SamplesImmune cell infiltration in myositis were by examining microarray expression profiles in muscle biopsies from 31 myositis patients and 5 normal controls.
Genomic signatures characterize leukocyte infiltration in myositis muscles.
Sex, Specimen part, Disease, Disease stage
View SamplesZinc finger nucleases (ZFN) are powerful tools for editing genes in cells. Here we use ZFNs to interrogate the biological function of human ADPGK, which encodes an ADP-dependent glucokinase (ADPGK), in tumour cell lines. The hypothesis tested is that ADPGK utilises ADP to phosphorylate glucose under conditions where ATP becomes limiting, such as hypoxia. We characterised two ZFN knockout clones in each of two tumour cell lines (H460 and HCT116). All four lines had frameshift mutations in all alleles at the target site in exon 1 of ADPGK, and were ADPGK-null by immunoblotting. ADPGK knockout had little or no effect on cell proliferation, but compromised the ability of H460 cells to survive siRNA silencing of hexokinase-2 under oxic conditions, with clonogenic survival falling from 213% for the parental line to 6.40.8% (p=0.002) and 4.30.8% (p=0.001) for the two knockouts. A similar increased sensitivity to clonogenic cell killing was observed under anoxia. No such changes were found when ADPGK was knocked out in HCT116 cells, for which the parental line was less sensitive than H460 to anoxia and to hexokinase-2 silencing. While knockout of ADPGK in HCT116 cells caused few changes in global gene expression, knockout of ADPGK in H460 cells caused notable up-regulation of mRNAs encoding cell adhesion proteins. Surprisingly, we could discern no effect on glycolysis as measured by glucose consumption or lactate formation under oxic or anoxic conditions, or extracellular acidification rate (Seahorse XF analyser) under oxic conditions in a variety of media. However, oxygen consumption rates were generally lower in the ADPGK knockouts, in some cases markedly so. Collectively, the results demonstrate that ADPGK can contribute to tumour cell survival under conditions of high glycolytic dependence, but the phenotype resulting from knockout of ADPGK is cell line dependent and appears to be unrelated to priming of glycolysis.
Expression and role in glycolysis of human ADP-dependent glucokinase.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The plasma cell signature in autoimmune disease.
Specimen part, Treatment, Time
View SamplesObjective: Production of pathogenic autoantibodies by self-reactive plasma cells (PC) is a hallmark of autoimmune diseases. Investigating the prevalence of PC in autoimmune disease and their relationship with known pathogenic pathways may increase our understanding of the role of PC in disease progression and treatment response. Methods: We developed a sensitive gene expression based method to overcome the challenges of measuring PC using flow cytometry. Whole genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA, IGJ, IGKC, IGKV, and TNFRSF17, expressed predominantly in PC. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy; evaluating the relationship between PC and other autoimmune disease-related genes; and estimating PC levels in affected blood and tissue from multiple autoimmune diseases. Results: The PC signature was highly sensitive and capable of detecting as few as 300 PCs. The PC signature was reduced over 90% in scleroderma patients following anti-CD19 treatment and this reduction was highly correlated (r = 0.77) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed 30-35% of lupus, rheumatoid arthritis, and scleroderma patients with increased PC levels. Conclusion: This newly developed PC signature provides a robust and accurate method to measure PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases that may benefit from PC depleting therapy.
The plasma cell signature in autoimmune disease.
Specimen part, Treatment, Time
View Samples