Transcription profiling of human peripheral blood mononuclear cells (PMBCs) from male patients with post-viral chronic fatigue (n=8) and male healthy control subjects (n=7) to identify a gene signature for Chronic Fatigue Syndrome
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ABSTRACT: Human genome-wide Affymetrix GeneChip arrays were used to compare the levels of gene expression in the peripheral blood mononuclear cells (PMBCs) of male patients with post-viral chronic fatigue (n=8) and male healthy control subjects (n=7). Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance. Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment. Experiment Overall Design: Two groups of patients: Chronic Syndrom Fatigue (CFS) patients (n=8) and control patients (n=7).
Project description:Background. Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes. Methods. Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue. Biological sampling conditions were standardized and RNA stabilizing media were used. These methodological features provide rigorous control for bias resulting from case-control mismatched ancestry and experimental error. Individual gene expression profiles were assessed using Affymetrix Human Genome U133 Plus 2.0 arrays. Findings. There were no significant differences in gene expression for any transcript. Conclusions. Contrary to our expectations, we were unable to identify a biomarker for chronic fatiguing illness in the transcriptome of peripheral blood leukocytes suggesting that positive findings in prior studies may have resulted from experimental bias. Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue.
Project description:Human genome-wide Affymetrix GeneChip arrays were used to compare the levels of gene expression in the peripheral blood mononuclear cells (PMBCs) of male patients with post-viral chronic fatigue (n=8) and male healthy control subjects (n=7). Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance. Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment. Keywords: comparison between two groups of samples
Project description:Genome-wide analysis of DNA methylation profiles from patients with Sjögren's syndrome with high versus low fatigue levels using the Illumina Infinium HumanMethylation450 Beadchip array. Background Chronic fatigue is a common, disabling, and poorly understood phenomenon. Recent studies indicate that epigenetic mechanisms may be involved in the expression of fatigue, a prominent feature of primary Sjögrenâs syndrome (pSS). The aim of this study was to investigate whether DNA methylation profiles of whole blood are associated with fatigue in patients with pSS. Methods 48 pSS patients with high (n=24) or low (n=24) fatigue as measured by a visual analogue scale were included. Genome-wide DNA methylation was investigated using the Illumina HumanMethylation450 BeadChip array. Case-case study including Sjögren's patients with high fatigue (n=24) and patients with low fatigue levels (n=24)
Project description:Background. Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes. Methods. Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue. Biological sampling conditions were standardized and RNA stabilizing media were used. These methodological features provide rigorous control for bias resulting from case-control mismatched ancestry and experimental error. Individual gene expression profiles were assessed using Affymetrix Human Genome U133 Plus 2.0 arrays. Findings. There were no significant differences in gene expression for any transcript. Conclusions. Contrary to our expectations, we were unable to identify a biomarker for chronic fatiguing illness in the transcriptome of peripheral blood leukocytes suggesting that positive findings in prior studies may have resulted from experimental bias.
Project description:HIV-related fatigue is multi-causal in origin and potentially related to mitochondrial dysfunction caused by toxicity from nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral therapy. CD14+ cells are undifferentiated macrophages, vulnerable to HIV infection, and easily accessible for gene expression experiments in a purified cell population. We utilized a novel mitochondrially-specific gene expression microarray to assess mitochondrial and nuclear genes in CD14+ cells of low- and high-fatigued, NRTI-treated HIV/AIDS patients (n=5 each). Novel Bayesian and liquid association network methods identified 33 genes predictive of low versus high fatigue and 32 genes predictive of healthy versus HIV infection. Sulfotransferase 2B1 (SULT2B1) is relevant to both the cholesterol and testosterone pathway, and like several inner mitochondrial membrane genes also identified, predictive of fatigue status, while outer mitochondrial membrane genes were predictive of HIV status. A surprising finding was that adenylate cyclase 2 (ADCY2) was a predictor of both HIV and fatigue; it had the highest Kendallâs Tau association value in the HIV group, but in reverse, the lowest Tau value in the fatigue group. Assaying CD14+ cells may provide an alternative to muscle biopsy and a minimally invasive procedure to evaluate patient mitochondrial function, and Bayesian and network tools are useful to identify the link between subjective symptom perceptions and underlying biologically pathways. Fatigue status in HIV patients treated with NRTIs was found to be linked to RNA expression differences related to mitochondrial function. Additional studies are needed to confirm the relevance of our findings in CD14+ cells in other tissues (e. g. skeletal muscle) and to understand the significance of key genes such as SULT2B and ADCY2 in fatigue and HIV disease. The design was a comparison of HIV high fatigue to HIV low fatigue. Low fatigue was determined as 3-7 on the Revised Piper Fatigue Score and High fatigue was a score of 7 or greater. Five HIV negative control samples were used to compare normal fatigue and non-disease status.
Project description:Fatigue is a debilitating condition with a significant impact on patientsâ quality of life. Fatigue is frequently reported by patients suffering from primary Sjo Ìgrenâs Syndrome (pSS), a chronic autoimmune condition characterised by dryness of the eyes and the mouth. However, although fatigue is common in pSS, it does not manifest in all sufferers, providing an excellent model with which to explore the potential underpinning biological mechanisms. Whole blood samples from 131 fully-phenotyped pSS patients, stratified for the presence of fatigue, collected by the UK primary Sj Ìogrenâs Syndrome Registry were used for whole genome microarray. The resulting data were analysed both on a gene by gene basis and using pre-defined groups of genes. Finally, gene set enrichment analysis (GSEA) was used as a feature selection technique for input into a support vector machine (SVM) classifier. Classification was assessed using area under curve (AUC) of receiver operator characteristic and standard error of Wilcoxon statistic, SE(W). Contributor: The UK Primary Sjögrenâs syndrome registry
Project description:Interferon (IFN)-alpha causes high rates of depression and fatigue, and is used to investigate the impact of innate immune cytokines on brain and behavior. However, little is known about transcriptional profiles of circulating immune cells during chronic IFN-alpha administration. Accordingly, genome-wide transcriptional profiling was performed on peripheral blood mononuclear cells from 21 patients with chronic hepatitis C virus either awaiting IFN-alpha therapy (n=10) or after 12 weeks of IFN-alpha treatment (n=11). Significance analysis of microarray data identified 252 up-regulated gene transcripts, the majority of which were related to IFN-alpha/antiviral or innate-immune/inflammatory signaling. Of these upregulated genes, 2'-5'-oligoadenylate synthetase 2 (OAS2) was the only gene that was differentially expressed in patients that developed IFN-alpha-induced depression/fatigue, and correlated with depression and fatigue scores at 12 weeks of IFN-alpha administration. Promoter-based bioinformatic and cellular origin analyses revealed IFN-alpha-induced increases in genes bearing transcription factor binding motifs (TFBMs) related to myeloid differentiation, IFN-alpha signaling, API and CREB/ATF family of transcription pathways, with changes derived primarily from monocytes and plasmacytoid dendritic cells. Patients with high depression/fatigue scores demonstrated up-regulation of genes bearing TFBMs for myeloid differentiation, IFN-alpha and AP1 signaling, and down regulation of TFBMs for CREB/ATF-related transcription factors. Cellular origin analyses indicated a shift toward genes derived from CD8+T and NK cells in subjects with high depression/fatigue scores. These results reveal an antiviral and inflammatory transcriptional profile after 12 weeks IFN-alpha, accompanied by increased OAS2 expression, decreased CREB/ATF transcriptional control, and a shift from monocyte-derived genes to those of cytotoxic lymphocytes in IFN-alpha-induced depression/fatigue. Total RNA was isolated from the peripheral blood mononuclear cells (PBMC) obtained at 12 weeks from HCV patients treated with IFN-alpha plus ribavirin (n=11) and untreated HCV patients awaiting IFN-alpha/ribavirin therapy (control subjects, n=10).
Project description:Chronic Fatigue Syndrome (CFS), also known as myalgic encephalomyelitis, is a complex multifactorial disease that is characterized by the persistent presence of fatigue and other particular symptoms for a minimum of 6 months. Symptoms fail to dissipate after sufficient rest and have major effects on the daily functioning of CFS sufferers. CFS is a multi-system disease with a heterogeneous patient population showing a wide variety of functional disabilities and its biological basis remains poorly understood. Stable alterations in gene function in the immune system have been reported in several studies of CFS. Epigenetic modifications have been implicated in long-term effects on gene function, however, to our knowledge, genome-wide epigenetic modifications associated with CFS have not been explored. We examined the DNA methylome in peripheral blood mononuclear cells isolated from CFS patients and healthy controls using the Illumina HumanMethylation450 BeadChip array, controlling for invariant probes and probes overlapping polymorphic sequences. Genomic DNA from 24 peripheral blood mononuclear cells (PBMC) samples (12 CFS, 12 controls) were bisulfite-converted and hybridised to the Illumina Infinium HumanMethylation450 BeadChip. GenomeStudio files were generated and the data was analyzed using the Illumina Methylation Analyzer R package.
Project description:Chronic Fatigue Syndrome (CFS), also known as myalgic encephalomyelitis, is a complex multifactorial disease that is characterized by the persistent presence of fatigue and other particular symptoms for a minimum of 6 months. Symptoms fail to dissipate after sufficient rest and have major effects on the daily functioning of CFS sufferers. CFS is a multi-system disease with a heterogeneous patient population showing a wide variety of functional disabilities and its biological basis remains poorly understood. Stable alterations in gene function in the immune system have been reported in several studies of CFS. Epigenetic modifications have been implicated in long-term effects on gene function, however, to our knowledge, genome-wide epigenetic modifications associated with CFS have not been explored. We examined the DNA methylome in peripheral blood mononuclear cells isolated from CFS patients and healthy controls using the Illumina HumanMethylation450 BeadChip array, controlling for invariant probes and probes overlapping polymorphic sequences.
Project description:Genome-wide analysis of DNA methylation profiles from patients with Sjögren's syndrome with high versus low fatigue levels using the Illumina Infinium HumanMethylation450 Beadchip array. Background Chronic fatigue is a common, disabling, and poorly understood phenomenon. Recent studies indicate that epigenetic mechanisms may be involved in the expression of fatigue, a prominent feature of primary Sjögren’s syndrome (pSS). The aim of this study was to investigate whether DNA methylation profiles of whole blood are associated with fatigue in patients with pSS. Methods 48 pSS patients with high (n=24) or low (n=24) fatigue as measured by a visual analogue scale were included. Genome-wide DNA methylation was investigated using the Illumina HumanMethylation450 BeadChip array.