Variation in RNA-Seq transcriptome profiles of peripheral whole blood from healthy individuals with and without globin depletion
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Scott Tebbutt
PROVIDER: E-GEOD-53655 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Room temperature whole blood mRNA stabilization procedures, such as the PAX gene system, are critical for the application of transcriptional analysis to population-based clinical studies. Global transcriptome analysis of whole blood RNA using microarrays has proven to be challenging due to the high abundance of globin transcripts that constitute 70% of whole blood mRNA in the blood. This is a particular problem in patients with sickle-cell disease, secondary to the high abundance of globin-expressing nucleated red blood cells and reticulocytes in the circulation . In order to more accurately measure the steady state whole blood transcriptome in sickle-cell patients, we evaluated the efficacy of reducing globin transcripts in PAXgene stabilized RNA samples for genome-wide transcriptome analyses using oligonucleotide arrays. We demonstrate here by both microarrays and Q-PCR that the globin mRNA depletion method resulted in 55-65 fold reduction in globin transcripts in whole blood collected from healthy volunteers and sickle-cell disease patients. This led to an improvement in microarray data quality with increased detection rate of expressed genes and improved overlap with the expression signatures of isolated peripheral blood mononuclear (PBMC) preparations. The differentially modulated genes from the globin depleted samples had a higher correlation coefficient to the 112 genes identified to be significantly altered in our previous study on sickle-cell disease using PBMC preparations. Additionally, the analysis of differences between the whole blood transcriptome and PBMC transcriptome reveals important erythrocyte genes that participate in sickle-cell pathogenesis and compensation. The combination of globin mRNA reduction after whole-blood RNA stabilization represents a robust clinical research methodology for the discovery of biomarkers for hematologic diseases and in multicenter clinical trials investigating a wide range of nonhematologic disorders where fractionation of cell types is impracticable. Keywords: Microarrays, PAXgene, globin reduction, whole blood, PBMC There are 10 samples for each of PBMC, PAX and PAX globin-reduced, where 5 samples come from sickle-cell patients and 5 from healthy controls.
2009-06-20 | E-GEOD-16728 | biostudies-arrayexpress
Project description:Microarray-based gene expression analysis of peripheral whole blood is a common strategy in the development of clinically relevant biomarker panels for a variety of human diseases. However, the results of such an analysis are often plagued by decreased sensitivity and reliability due to the effects of relatively high levels of globin mRNA in whole blood. Globin reduction assays have been shown to overcome such effects, but they require large amounts of total RNA and may induce distinct gene expression profiles. The Illumina whole-genome DASL (WG-DASL) assay can detect gene expression levels using partially degraded RNA samples and has the potential to detect rare transcripts present in highly heterogeneous whole blood samples without the need for globin reduction. We therefore assessed the utility of the WG-DASL assay in the analysis of peripheral whole blood gene expression profiles. We find that gene expression detection is significantly increased with the use of WG-DASL compared to the standard in vitro transcription-based direct hybridization (IVT), while globin-probe-negative WG-DASL did not exhibit significant improvements over globin-probe-positive WG-DASL. Globin reduction increases the detection sensitivity and reliability of both WG-DASL and IVT with little effect on raw intensity correlations: raw intensity correlations between total RNA and globin-reduced RNA were 0.970 for IVT and 0.981 for WG-DASL. Overall, the detection sensitivity of the WG-DASL assay is higher than the IVT-based direct hybridization assay, with or without globin reduction, and should be considered in conjunction with globin reduction methods for future blood-based gene expression studies. Peripheral whole blood samples were collected from eight human donors in PAXGene tubes. RNA was isolated after freezing and storage, and then prepared for gene expression analysis using the Illumina Human-Ref8 v3.0 BeadChip. Alpha and beta globin were reduced from a portion of the total RNA using the GLOBINclear assay (Ambion, Austin, TX, USA). Two methods of microarray target preparation were examined: Illumina IVT-based direct hybridization (IVT) and Illumina Whole-Genome DASL (WG-DASL). Two DASL Assay Oligo pools (DAP) were utilized for DASL target preparation: the DASL Assay Oligo Pool with globin probes (DAP +) and the DASL Asssay Oligo Pool without globin probes (DAP-).
2011-04-01 | E-GEOD-28064 | biostudies-arrayexpress
Project description:Whole blood rather than purified peripheral blood mononuclear cells is likely to become the prime tissue using expression microarrays for disease predication or prognosis however excess of globin mRNA may reduce probe detection sensitivity. In our study, we assessed whether whole-blood or globin-reduced RNA gives the most robust and sensitive results to detect small gene expression changes in response to hormone replacement therapy exposure. Each sample (N = 12) were hybridized according to 3 different protocols: no globin reduction (controls), globin reduction using peptid nucleic acids (PNA) and using magnetic beads in the GlobinClear kit from Ambion. Finally, 7 and 4 technical replicates were conducted in no globin reduction and PNA groups, respectively. Both globin reduction approaches were mostly efficient at reducing globin RNA from cRNA. Samples processed by GlobinClear kit gave a very distinct gene expression profiles from the controls while samples processed with PNA gave an intermediary profile closest to the non globin reduction group with a slight increased sensitivity of transcript detection but a loss of reproducibility. Overall, no sign of higher sensitivity in detection of gene expression changes followed by hormone exposure was observed after globin reduction which was therefore judged not beneficial. Keywords: Groups comparaison To assess effect of globin reduction protocols on gene expression from whole-blood, we selected 12 postmenopausal women (6 HRT users and 6 non-HRT users) who were not using other medication than HRT at the time of blood sampling and in order to cover a wide body mass index (BMI) range in both HRT and non HRT users. The samples were also selected to contain the highest concentration of total extracted RNA. Each sample was hybridized according to 3 different protocols: no globin reduction (controls), globin reduction using PNAs, globin reduction using magnetic beads in the GlobinClear™ kit from Ambion. The reproducibility of the globin reduction method compared to the non globin reduction approach was investigated for the PNA method only since this method was the most effective and specific. We planned to conduct 7 technical replicates in each group (i.e. no globin reduction and PNA groups). During amplification process with PNA, 4 samples failed to reverse transcript long fragment of mRNA certainly due to inhibitory contamination and these arrays were therefore excluded from our analyses. One sample (sample 34) was amplified with PNA twice the same day to study technical reproducibility without amplification date effect. Finally, a total of 47 arrays were conducted including 7 and 4 technical replicates in no globin reduction and PNA group, respectively.
2008-02-11 | E-GEOD-7008 | biostudies-arrayexpress
Project description:RNA extracted from whole blood of healthy controls or podoconiosis patients and subject to RNA sequencing. Total RNA libraries were prepared using the QIAseq Stranded RNA library kit with rRNA and globin RNA depleted using the QIAseq FastSelect rRNA and globin mRNA removal kit.
2024-03-14 | E-MTAB-13860 | biostudies-arrayexpress
Project description:Detecting differential changes in the peripheral whole-blood transcriptome, post-challenge compared to pre-challenge; using globin reduced PAXgene (PAX.GR) tubes Blood was collected immediately prior to, and two hours after challenge Blood samples from 4 subjects were used to study the effects of globin reduction on differential gene expression Preprocessing and filtering were applied to the PAX.GR dataset using the Factor Analysis for Robust MicroArray Summarization (farms) package in R The Linear Models for MicroArrays (limma) package in R was used to determine differential gene expression using a Benjamini Hochberg FDR of 5%.
2012-01-26 | E-GEOD-34158 | biostudies-arrayexpress
Project description:The transcriptional responses of human hosts towards influenza viral pathogens are important for understanding virus-mediated immunopathology. Despite great advances gained through studies using model organisms, the complete temporal host transcriptional responses in a natural human system are poorly understood. In a human challenge study using live influenza (H3N2/Wisconsin) viruses, we conducted a clinically uninformed (unsupervised) factor analysis on gene expression profiles and established an ab initio molecular signature that strongly correlates to symptomatic clinical disease. This is followed by the identification of 42 biomarkers whose expression patterns best differentiate early from late phases of infection. In parallel, a clinically informed (supervised) analysis revealed over-stimulation of multiple viral sensing pathways in symptomatic hosts and linked their temporal trajectory with development of diverse clinical signs and symptoms. The resultant inflammatory cytokine profiles were shown to contribute to the pathogenesis because their significant increase preceded disease manifestation by 36 hours. In subclinical asymptomatic hosts, we discovered strong transcriptional regulation of genes involved in inflammasome activation, genes encoding virus interacting proteins, and evidence of active anti-oxidant and cell-mediated innate immune response. Taken together, our findings offer insights into influenza virus-induced pathogenesis and provide a valuable tool for disease monitoring and management in natural environments. During the challenge study, subjects had peripheral blood taken 24 hours prior to inoculation with virus (baseline), immediately prior to inoculation (pre-challenge) and at set intervals (8 hour intervals) following challenge. RNA was extracted at Expression Analysis (Durham, NC) from whole blood using the PAXgene™ 96 Blood RNA Kit (PreAnalytiX, Valencia, CA) employing the manufacturer's recommended protocol. While whole blood RNA is initially extracted, a secondary procedure (B-globin reduction) was then employed to remove the contribution of red blood cell (RBC) RNA to the total RNA. A set of four peptide nucleic acid (PNA) oligomers whose sequences are complementary to the 3’ portions of the alpha and beta hemoglobin RNA transcripts were added to reduce globin RNA transcription due to RBC. The inhibition of globin cDNA synthesis dramatically reduces the relative amount of anti-sense, biotin-labeled cRNA corresponding to the hemoglobin transcripts. Hybridization and microarray data collection was performed using the Human Genome U133A 2.0 Array (Affymetrix, Santa Clara, CA) and expression profiles were pre-processed using robust multi-array (RMA) method
2011-07-12 | E-GEOD-30550 | biostudies-arrayexpress
Project description:Whole blood was collected from chronic granulomatous patients, carriers and healthy controls. RNA was isolated from whole blood and globin removal was performed for all samples. The cells were not selecter or stimulated ex vivo.
2014-11-01 | E-GEOD-44969 | biostudies-arrayexpress
Project description:We hypothesized that patients with sarcoidosis have characteristic mRNA profiles. Microarray analysis of gene expression was done on peripheral blood. Comparing peripheral blood from patients with sarcoidosis to controls, 872 transcripts were upregulated and 1039 were downregulated at >1.5-fold change and a significant q value. Several transcripts associated with interferon and STAT1 were upregulated. Lung and lymph node analyses also showed dramatic increases in STAT1 and STAT1-regulated chemokines. Granulomas in lymph nodes of patients with sarcoidosis expressed abundant STAT1 and phosphorylated STAT1. STAT1 might play an important role in sarcoidosis. This novel hypothesis unites seemingly disparate observations with regard to sarcoidosis including implication of a casual role for interferons, a suspected infectious trigger, TH1 predominating lymphocytes in bronchoalveolar lavage, and the association with hypercalcemia. This study tested the hypothesis that SpA is characterized by a distinct pattern of gene expression in peripheral blood of affected individuals compared with healthy controls. High-density, human GeneChip probe arrays were used to profile mRNA of peripheral blood cells from 18 subjects with SpA and 25 normal individuals. Samples were processed as two separate sets at different times. Blood samples were taken at a time when patients were not receiving systemic immunomodulatory therapy. Differential expression was defined as a 1.5-fold change with a q value <5%. Gene ontology and pathway information were also studied. Signals from 134 probe sets (representing 95 known and 12 unknown gene transcripts) were consistently different from controls in both Sets 1 and 2. Included among these were transcripts for a group of 20 genes, such as interleukin-1 receptors 1 and 2, NLRP2, SLPI, SPARC, and TREM-1 that are clearly related to the immune or inflammatory response and a group of 4 transcripts that have a strong role in bone remodeling. Our observations are the first to implicate SPARC, SLPI, and NLRP2, a component of the innate immune system, in the pathogenesis of SpA. Our results also indicate a possible role for interleukin-1 and its receptors in SpA. In accord with the bone pathology component of SpA, we also found that expression levels of transcripts reflecting bone remodeling factors are also distinguishable in peripheral blood from patients with SpA versus controls. These results confirm some previously identified biomarkers implicated in the pathogenesis of SpA and also point to novel mediators in this disease. Peripheral blood was collected from diseased and control subjects. The sarcoidosis portion of the study included 12 patients and 12 control subjects. The spondyloarthropathy study was done in two independent sets. The first set included 11 patients and the same 12 control subjects used for the sarcoidosis study. The second set included 7 patients and 13 control subjects. For each sample, total RNA was isolated and analyzed by hybridization on Affymetrix arrays.
2009-11-04 | E-GEOD-18781 | biostudies-arrayexpress
Project description:Peripheral blood was collected into PAXgene tubes from 7 patients with follicular lymphoma, in a phase 2 clinical trial of lenalidomide plus rituximab as initial therapy for advanced-stage indolent non-Hodgkin's lymphoma. Blood was collected at baseline and on Day 15 of the second 28-day cycle, for determination of the gene expression profile after globin mRNA reduction. The effect of treatment on gene expression profiles was largely based on the paired t test, using the Significance Analysis of Microarrays method.
2014-02-06 | E-GEOD-54740 | biostudies-arrayexpress
Project description:Peripheral whole blood-based gene expression profiling has become one of the most common strategies exploited in the development of clinically relevant biomarkers. However, the ability to identify biologically meaningful conclusions from gene expression patterns in whole blood is highly problematic. First, it is difficult to know whether or not expression patterns in whole blood capture those in primary tissues. Second, if explicit steps are not taken to accommodate the extremely elevated expression levels of globin in blood then large-scale multi-probe microarray-based studies can be severely compromised. Many studies consider the use of mouse blood as a model for human blood in addition to considering blood gene expression levels as a general surrogate for gene expression levels in other tissues. We explored the effects of globin reduction on peripheral mouse blood in the detection of genes known to be expressed in human tissues. Globin reduction resulted in 1.) a significant increase in the number of probes detected (5840 ± 944 vs 12411 ± 1904); 2.) increased expression for 4128 probe sets compared to non-globin reduced blood (p < .001, ≥ two-fold); 3.) improved detection of genes associated with many biological pathways and diseases; and 4.) an increased ability to detect genes expressed in 27 human tissues (p < 10-4). This study suggests that although microarray-based mouse blood gene expression studies that do not consider the effects of globin are severely compromised, globin-reduced mouse whole blood gene expression studies can be used to capture the expression profiles of genes known to contribute to various human diseases. Whole and GLOBINclear-treated paired blood samples from 18 mice representing 3 mice from 6 different isogenic mice strains.
2010-07-22 | E-GEOD-19282 | biostudies-arrayexpress