Differential gene expression profiling in whole blood during acute systemic inflammation in lipopolysaccharide-treated rats

National Center for Toxicogenomics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
Physiological Genomics (Impact Factor: 2.37). 04/2005; 21(1):92-104. DOI: 10.1152/physiolgenomics.00190.2004
Source: PubMed


Microarrays have been used to evaluate the expression of thousands of genes in various tissues. However, few studies have investigated the change in gene expression profiles in one of the most easily accessible tissues, whole blood. We utilized an acute inflammation model to investigate the possibility of using a cDNA microarray to measure the gene expression profile in the cells of whole blood. Blood was collected from male Sprague-Dawley rats at 2 and 6 h after treatment with 5 mg/kg (ip) LPS. Hematology showed marked neutrophilia accompanied by lymphopenia at both time points. TNF-alpha and IL-6 levels were markedly elevated at 2 h, indicating acute inflammation, but by 6 h the levels had declined. Total RNA was isolated from whole blood and hybridized to the National Institute of Environmental Health Sciences Rat Chip v.3.0. LPS treatment caused 226 and 180 genes to be differentially expressed at 2 and 6 h, respectively. Many of the differentially expressed genes are involved in inflammation and the acute phase response, but differential expression was also noted in genes involved in the cytoskeleton, cell adhesion, oxidative respiration, and transcription. Real-time RT-PCR confirmed the differential regulation of a representative subset of genes. Principal component analysis of gene expression discriminated between the acute inflammatory response apparent at 2 h and the observed recovery underway at 6 h. These studies indicate that, in whole blood, changes in gene expression profiles can be detected that are reflective of inflammation, despite the adaptive shifts in leukocyte populations that accompany such inflammatory processes.

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Available from: Todd Auman, Sep 30, 2015
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    • "In the present study, we aimed to characterize the suitability of cOFM for monitoring BBB function and cerebral cytokine production in a rat model. We adopted a well-characterized model for acute systemic inflammation induced by a septic dose of lipopolysaccharide (LPS) [22] to study cytokine synthesis in the brain, and utilized Naf as a marker for BBB permeability. Systemic administration of LPS produces an acute inflammatory response in the brain, which includes BBB disruption [23] and release of cytokines [24], [25]. "
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    ABSTRACT: Blood-brain barrier (BBB) impairment in systemic inflammation leads to neuroinflammation. Several factors including cytokines, chemokines and signal transduction molecules are implicated in BBB dysfunction in response to systemic inflammation. Here, we have adopted a novel in vivo technique; namely, cerebral open flow microperfusion (cOFM), to perform time-dependent cytokine analysis (TNF-alpha, IL-6 and IL-10) in the frontal cortex of the rat brain in response to a single peripheral administration of lipopolysaccharide (LPS). In parallel, we monitored BBB function using sodium fluorescein as low molecular weight reporter in the cOFM sample. In response to the systemic LPS administration, we observed a rapid increase of TNF-alpha in the serum and brain, which coincides with the BBB disruption. Brain IL-6 and IL-10 synthesis was delayed by approximately 1 h. Our data demonstrate that cOFM can be used to monitor changes in brain cytokine levels and BBB disruption in a rat sepsis model.
    PLoS ONE 05/2014; 9(5):e98143. DOI:10.1371/journal.pone.0098143 · 3.23 Impact Factor
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    • "After decapitation, neck blood samples (2.5 mL) were collected in PaxGene RNA collection tubes (PreAnalytiX) according to the manufacturer's recommendations. Two hours after collection, total RNA was extracted using PaxGene blood RNA isolation kit (PreAnalytiX) with minor modification [34]. After RNA extraction, RNA was treated with DNaseI and the quality of the RNA was evaluated by electrophoresis in agarose gel. "
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    ABSTRACT: Sleep is a restorative process and is essential for maintenance of mental and physical health. In an attempt to understand the complexity of sleep, multidisciplinary strategies, including genetic approaches, have been applied to sleep research. Although quantitative real time PCR has been used in previous sleep-related gene expression studies, proper validation of reference genes is currently lacking. Thus, we examined the effect of total or paradoxical sleep deprivation (TSD or PSD) on the expression stability of the following frequently used reference genes in brain and blood: beta-actin (b-actin), beta-2-microglobulin (B2M), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and hypoxanthine guanine phosphoribosyl transferase (HPRT). Neither TSD nor PSD affected the expression stability of all tested genes in both tissues indicating that b-actin, B2M, GAPDH and HPRT are appropriate reference genes for the sleep-related gene expression studies. In order to further verify these results, the relative expression of brain derived neurotrophic factor (BDNF) and glycerol-3-phosphate dehydrogenase1 (GPD1) was evaluated in brain and blood, respectively. The normalization with each of four reference genes produced similar pattern of expression in control and sleep deprived rats, but subtle differences in the magnitude of expression fold change were observed which might affect the statistical significance. This study demonstrated that sleep deprivation does not alter the expression stability of commonly used reference genes in brain and blood. Nonetheless, the use of multiple reference genes in quantitative RT-PCR is required for the accurate results.
    BMC Molecular Biology 02/2009; 10(1):45. DOI:10.1186/1471-2199-10-45 · 2.19 Impact Factor
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    • "oncology, new drugs testing, etc.). Many works now aim at applying this high-throughput tool to toxicological studies [5], [10], for which the ultimate purposes are to know whether an individual has been intoxicated and if so, to identify the toxicant and possibly to predict the exposure level. Because the clinical signs are the same for a wide range of toxicants, a molecular imprint yielded by gene expression, the so called molecular signature, of these toxicants would help the design of a fast and efficient diagnostic tool. "
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    ABSTRACT: Gene expression profiling in toxicogenomics is often used to find molecular signature of toxicants. The range of doses chosen in toxicogenomics studies does not always represent all the possible effects on gene expression: several doses of toxicant can lead to the same observable effect on the transcriptome. This makes the problem of dose exposure prediction difficult to address. We propose a strategy allowing to gather the doses with similar effects prior to the computing of a molecular signature. The different gatherings of doses are compared with criteria based on likelihood or Monte Carlo cross validation. The molecular signature is then determined via a voting algorithm. Experimental results point out that the obtained classifier has better prediction performances than the classifier computed according to the original labeling.
    International Conference on Biocomputation, Bioinformatics, and Biomedical Technologies, BIOTECHNO 2008, June 29 - July 5, 2008, Bucharest, Romania; 01/2008
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