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GSE11524
Homo sapiens
26 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
In sickle cell disease, ischemia-reperfusion injury and intravascular hemolysis produce endothelial dysfunction and vasculopathy characterized by reduced nitric oxide (NO) and arginine bioavailability. Recent functional studies of platelets in patients with sickle cell disease reveal a basally activated state, suggesting that pathological platelet activation may contribute to sickle cell disease vasculopathy. Studies were therefore undertaken to examine transcriptional signaling pathways in platelets that may be dysregulated in sickle cell disease. We demonstrate and validate here the feasibility of comparative platelet transcriptome studies on clinical samples from single donors, by the application of RNA amplification followed by microarray-based analysis of 54,000 probe sets. Data mining an existing microarray database, we identified 220 highly abundant genes in platelets and a subset of 72 relatively platelet-specific genes, defined by more than 10-fold increased expression compared to the median of other cell types in the database with amplified transcripts. The highly abundant platelet transcripts found in the current study included 82% or 70% of platelet abundant genes identified in two previous gene expression studies on non-amplified mRNA from pooled or apheresis samples, respectively. On comparing the platelet gene expression profiles in 18 patients with sickle cell disease in steady state to 12 African American controls, at a 3-fold cut-off and 5% false discovery rate, we identified ~100 differentially expressed genes, including multiple genes involved in arginine metabolism and redox homeostasis. Further characterization of these pathways using real time PCR and biochemical assays revealed increased arginase II expression and activity and decreased platelet polyamine levels. These studies suggest a potential pathogenic role for platelet arginase and altered arginine and polyamine metabolism in sickle cell disease and provide a novel framework for the study of disease-specific platelet biology.
Publication Title
Amplified expression profiling of platelet transcriptome reveals changes in arginine metabolic pathways in patients with sickle cell disease.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 65 Downloadable Samples
- Affymetrix Human Genome U219 Array (hgu219)
Description
Hepatitis C virus (HCV) chronically infects 170 million people worldwide and is a leading cause of liver-related mortality due to hepatocellular carcinoma and cirrhosis1. Standard-of-care treatment is shifting from interferon-alpha (IFN)-based to IFN-free directly acting antiviral (DAA) regimens, which demonstrate improved efficacy and tolerability in clinical trials2,3. Virologic relapse after completion of DAA therapy is a common cause of treatment failure, although mechanisms are unclear2,3. We conducted a clinical trial using the DAA sofosbuvir with ribavirin (SOF/RBV)4, and report here detailed mRNA expression analysis of pre- and end-of-treatment (EOT) liver biopsies and blood samples. On-treatment viral clearance was accompanied by rapid down-regulation of interferon-stimulated genes (ISGs) in liver and blood. Analysis of paired liver biopsies from patients who achieved a sustained virologic response (SVR) revealed that viral clearance was accompanied by decreased expression of ISGs, IFNG, and IFNLs, but increased expression of IFNA2. Patients who achieved SVR had higher expression of a hepatic type-I interferon gene signature in unpaired EOT liver biopsies than patients who later relapsed. Together, these results support a model whereby restoration of type-I intrahepatic interferon signaling at the EOT is associated with sustained hepatic HCV suppression and prevention of relapse upon withdrawal of SOF/RBV.
Publication Title
Endogenous intrahepatic IFNs and association with IFN-free HCV treatment outcome.
Sample Metadata Fields
Sex, Age, Specimen part, Time
View Samples- Homo sapiens
- 18 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Herpesviruses are known to encode micro (mi)RNAs and to use them to regulate the expression of both viral and cellular genes. The genome of Kaposis sarcoma herpesvirus (KSHV) encodes a cluster of twelve miRNAs, which are abundantly expressed during both latency and lytic infection. Relatively few cellular targets of KSHV miRNAs are known. Here, we used a microarray expression profiling approach to analyze the transcriptome of both B lymphocytes and endothelial cells stably expressing KSHV miRNAs and monitor the changes induced by the presence of these miRNAs. We generated a list of potential cellular targets by looking for miRNA seed-match-containing transcripts that were significantly down regulated upon KSHV miRNAs expression. Interestingly, the overlap of putative targets identified in B lymphocytes and endothelial cells was minimal, suggesting a tissue-specific target-regulation by viral miRNAs. Among the putative targets, we identified caspase 3, a critical factor for the control of apoptosis, which we validated using luciferase reporter assays and western blotting. In functional assays we obtained further evidence that KSHV miRNAs indeed protect cells from apoptosis.
Publication Title
Kaposi's sarcoma herpesvirus microRNAs target caspase 3 and regulate apoptosis.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 27 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Total, nascent and unlabeled RNA were prepared following 1h of labeling with 100 M 4-thiouridine and 3 replicates analyzed by Affymetrix Gene ST 1.0 arrays
Publication Title
Systematic analysis of viral and cellular microRNA targets in cells latently infected with human gamma-herpesviruses by RISC immunoprecipitation assay.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 24 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
RIP-Chip was performed on DG75-eGFP, DG75-10/12, BCBL-1, BL41, BL41 B95.8 and Jijoye using anti-human Ago2 (11A9) antibodies. Anti-BrdU antibodies were used as controls for DG75-eGFP, DG75-10/12 and BCBL-1. Total RNA was used as control for BL41, BL41 B95.8 and Jijoye. Samples were analyzed on Affymetrix Gene ST 1.0 Arrays (2 independent biological replicates / sample)
Publication Title
Systematic analysis of viral and cellular microRNA targets in cells latently infected with human gamma-herpesviruses by RISC immunoprecipitation assay.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 71 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Rhabdoid tumors (RTs) are aggressive tumors of early childhood that occur most often in brain (AT/RTs) or kidney (KRTs). Regardless of location, they are characterized by loss of functional SMARCB1 protein, a component of the SWI/SNF chromatin remodeling complex. The aim of this study was to determine genes and biological process dysregulated in common to both AT/RTs and KRTs. Gene expression for AT/RTs was compared to that of other brain tumors and normal brain using microarray data from our lab. Similar analysis was performed for KRTs and other kidney tumors and normal kidney using data from GEO. Dysregulated genes common to both analyses were analyzed for functional significance. Unsupervised hierarchical clustering of RTs identified 3 major subsets: 2 comprised of AT/RTs, and 1 of KRTs. Compared to other tumors, 1187, 663 and 539 genes were dysregulated in each subset, respectively. Only 14 dysregulated genes were common to all 3 subsets. Compared to normal tissue, 5209, 4275 and 2841 genes were dysregulated in each subset, with an overlap of 610 dysregulated genes. Among these genes, processes associated with cell proliferation, MYC activation, and epigenetic dysregulation were common to all 3 RT subsets. The low overlap of dysregulated genes in AT/RTs and KRTs suggests that factors in addition to SMARCB1 loss play a role in determining subsequent gene expression. Drugs which target cell cycle or epigenetic genes may be useful in all RTs. Additionally, targeted therapies tailored to specific RT subset molecular profiles should be considered.
Publication Title
Pediatric rhabdoid tumors of kidney and brain show many differences in gene expression but share dysregulation of cell cycle and epigenetic effector genes.
Sample Metadata Fields
Specimen part
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