Gene expression profiling of CsA or TBTO exposed primary mouse splenocytes
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ABSTRACT: primary splenocytes (C57BL6) were exposed to CsA (7.5 or 15 uM) TBTO (500nM) or DMSO (0.1% as control) for 6h. Gene expression profiling was performed by ServiceXS on GeneTitan430PM 16 array plate
Project description:Circadian rhythms are endogenous 24-h oscillations that influence a multitude of physiological processes. The pathogen-associated molecular pattern (PAMP), lipopolysaccharide, has been shown to modify the circadian molecular clock. The aim of this study was to determine if other PAMPs alter clock gene expression. Therefore, mRNA levels of clock genes (Per2, Bmal1, Rev-erbα, and Dbp) were measured after an ex vivo challenge with several PAMPs and to further test the relevance of PAMP alteration of the molecular clock, an in vivo poly(I:C) challenge was performed. This study revealed that several other PAMPs are also capable of altering clock gene expression.
Project description:BackgroundFibrates are a unique hypolipidemic drugs that lower plasma triglyceride and cholesterol levels through their action as peroxisome proliferator-activated receptor alpha (PPARalpha) agonists. The activation of PPARalpha leads to a cascade of events that result in the pharmacological (hypolipidemic) and adverse (carcinogenic) effects in rodent liver.ResultsTo understand the molecular mechanisms responsible for the pleiotropic effects of PPARalpha agonists, we treated mouse primary hepatocytes with three PPARalpha agonists (bezafibrate, fenofibrate, and WY-14,643) at multiple concentrations (0, 10, 30, and 100 microM) for 24 hours. When primary hepatocytes were exposed to these agents, transactivation of PPARalpha was elevated as measured by luciferase assay. Global gene expression profiles in response to PPARalpha agonists were obtained by microarray analysis. Among differentially expressed genes (DEGs), there were 4, 8, and 21 genes commonly regulated by bezafibrate, fenofibrate, and WY-14,643 treatments across 3 doses, respectively, in a dose-dependent manner. Treatments with 100 muM of bezafibrate, fenofibrate, and WY-14,643 resulted in 151, 149, and 145 genes altered, respectively. Among them, 121 genes were commonly regulated by at least two drugs. Many genes are involved in fatty acid metabolism including oxidative reaction. Some of the gene changes were associated with production of reactive oxygen species, cell proliferation of peroxisomes, and hepatic disorders. In addition, 11 genes related to the development of liver cancer were observed.ConclusionOur results suggest that treatment of PPARalpha agonists results in the production of oxidative stress and increased peroxisome proliferation, thus providing a better understanding of mechanisms underlying PPARalpha agonist-induced hepatic disorders and hepatocarcinomas.
Project description:The characteristics of tumor cells of primary vitreoretinal lymphoma (PVRL) have not been defined, although researches have shown that most cases are of diffuse large B-cell lymphoma (DLBCL). To determine the subtype and biological characteristics of tumor cells of PVRL, we performed a gene expression profiling analysis. RNA was extracted from the vitreous fluid of 7 PVRL patients and from nodal samples of 10 DLBCL patients: 6 of germinal center B-cell (GCB) type and 4 of activated B-cell (ABC) type determined by Hans' criteria. Six PVRL samples showed gene expression profiles that were similar to each other. The patterns were different from those of the ABC-type nodular DLBCL but relatively close to those of the GCB-type nodular DLBCL. Interestingly, all of the 6 examined PVRL samples had either MYD88L265P or mutation in the immunoreceptor tyrosine-based activation motif (ITAM) region of CD79B. Five PVRL patients with similar gene expression profiles were treated with a standardized regimen: intravitreal administration of methotrexate (MTX) followed by six courses of systemic high doses of MTX. As a result, 2 patients had CD79B mutations and showed early central nervous system (CNS) progression. Patients without CNS progression did not have this mutation. In conclusion, PVRL had unique genetic features: an expression pattern different from ABC-type and relatively close to GCB-type DLBCL. CD79B mutations showed potential to serve as prognostic markers for CNS progression.
Project description:Ketamine, a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, is associated with accelerated neuronal apoptosis in the developing rodent brain. In this study, postnatal day (PND) 7 rats were treated with 20 mg/kg ketamine or saline in six successive doses (s.c.) at 2-h intervals. Brain frontal cortical areas were collected 6 h after the last dose and RNA isolated and hybridized to Illumina Rat Ref-12 Expression BeadChips containing 22,226 probes. Many of the differentially expressed genes were associated with cell death or differentiation and receptor activity. Ingenuity Pathway Analysis software identified perturbations in NMDA-type glutamate, GABA and dopamine receptor signaling. Quantitative polymerase chain reaction (Q-PCR) confirmed that NMDA receptor subunits were significantly up-regulated. Up-regulation of NMDA receptor mRNA signaling was further confirmed by in situ hybridization. These observations support our working hypothesis that prolonged ketamine exposure produces up-regulation of NMDA receptors and subsequent over-stimulation of the glutamatergic system by endogenous glutamate, triggering enhanced apoptosis in developing neurons.
Project description:BackgroundIt has been estimated that more than 1 million workers in the United States are exposed to cobalt. Occupational exposure to 59 Co occurs mainly via inhalation and leads to various lung diseases. Cobalt is classified by the IARC as a possible human carcinogen (group 2B). Although there is evidence for in vivo and in vitro toxicity, the mechanisms of cobalt-induced lung toxicity are not fully known. The purpose of this work was to identify potential signatures of acute cobalt exposure using a toxicogenomic approach. Data analysis focused on some cellular processes and protein targets that are thought to be relevant for carcinogenesis, transport and biomarker research.ResultsA time course transcriptome analysis was performed on A549 human pulmonary cells, leading to the identification of 85 genes which are repressed or induced in response to soluble 59 Co. A group of 29 of these genes, representing the main biological functions, was assessed by quantitative RT-PCR. The expression profiles of six of them were then tested by quantitative RT-PCR in a time-dependent manner and three modulations were confirmed by Western blotting. The 85 modulated genes include potential cobalt carriers (FBXL2, ZNT1, SLC12A5), tumor suppressors or transcription factors (MAZ, DLG1, MYC, AXL) and genes linked to the stress response (UBC, HSPCB, BNIP3L). We also identified nine genes coding for secreted proteins as candidates for biomarker research. Of those, TIMP2 was found to be down-regulated and this modulation was confirmed, in a dose-dependent manner, at protein level in the supernatant of exposed cells.ConclusionMost of these genes have never been described as related to cobalt stress and provide original hypotheses for further study of the effects of this metal ion on human lung epithelial cells. A putative biomarker of cobalt toxicity was identified.
Project description:Exposure of adult humans to manganese (Mn) has long been known to cause neurotoxicity. Recent evidence also suggests that exposure of children to Mn is associated with developmental neurotoxicity. Astrocytes are critical for the proper functioning of the nervous system, and they play active roles in neurogenesis, synaptogenesis and synaptic neurotransmission. In this report, to help elucidate the molecular events underlying Mn neurotoxicity, we systematically identified the molecular targets of Mn in primary human astrocytes at a genome-wide level, by using microarray gene expression profiling and computational data analysis algorithms. We found that Mn altered the expression of diverse genes ranging from those encoding cytokines and transporters to signal transducers and transcriptional regulators. Particularly, 28 genes encoding proinflammatory chemokines, cytokines and related functions were up-regulated, whereas 15 genes encoding functions involved in DNA replication and repair and cell cycle checkpoint control were down-regulated. Consistent with the increased expression of proinflammatory factors, analysis of common regulators revealed that 16 targets known to be positively affected by the interferon-gamma signaling pathway were up-regulated by Mn(2+). In addition, 68 genes were found to be similarly up- or down-regulated by both Mn(2+) and hypoxia. These results from genomic analysis are further supported by data from real-time RT-PCR, Western blotting, flow cytometric and toxicological analyses. Together, these analyses show that Mn(2+) selectively affects cell cycle progression, the expression of hypoxia-responsive genes, and the expression of proinflammatory factors in primary human astrocytes. These results provide important insights into the molecular mechanisms underlying Mn neurotoxicity.
Project description:Global expression profiling by DNA microarrays provides a snapshot of cell and tissue status and becomes an essential tool in biological and medical sciences. Typical questions that can be addressed by microarray analysis in developmental biology include: (1) to find a set of genes expressed in a specific cell type; (2) to identify genes expressed commonly in multiple cell types; (3) to follow the time-course changes of gene expression patterns; (4) to demonstrate cell's identity by showing similarities or differences among two or multiple cell types; (5) to find regulatory pathways and/or networks affected by gene manipulations, such as overexpression or repression of gene expression; (6) to find downstream target genes of transcription factors; (7) to find downstream target genes of cell signaling; (8) to examine the effects of environmental manipulation of cells on gene expression patterns; and (9) to find the effects of genetic manipulation in embryos and adults. Here, we describe strategies for executing these experiments and monitoring changes of cell state with gene expression microarrays in application to mouse embryology. Both statistical assessment and interpretation of data are discussed. We also present a protocol for performing microarray analysis on a small amount of embryonic materials.
Project description:Heart disease remains the most frequent cause of death in the general population with increasing incidence in the elderly population. The pathologic failure of the aging heart may be related to structural and functional alterations in cardiac muscle cells. However, the molecular mechanisms underlying the aging-related decline in cardiac muscle function are largely unknown. To provide the first analysis of cardiac aging at the level of gene expression, we established and compared cDNA libraries from apparently healthy young and aged mouse ventricular cardiac muscle cells. We report the identification of genes that exhibit aging-related changes of mRNA levels. Aging expression profiles in aged hearts indicate decreased cellular adaptation and protection against stress-induced injury together with the development of contractile dysfunction. The data suggest reduced activity of the mitochondrial electron transport system and reduced levels of cardiac-specific transcription regulators. The cardiomyocyte aging profile of gene expression displays similarities with known heart disorders. Genes whose mRNA levels change with aging in cardiomyocytes might profoundly affect pathological changes in the heart.
Project description:Chronic stress contributes to the risk of developing depression; the habenula, a nucleus in epithalamus, is associated with many neuropsychiatric disorders. Using genome-wide gene expression analysis, we analyzed the transcriptome of the habenula in rats exposed to chronic restraint stress for 14 days. We identified 379 differentially expressed genes (DEGs) that were affected by chronic stress. These genes were enriched in neuroactive ligand-receptor interaction, the cAMP (cyclic adenosine monophosphate) signaling pathway, circadian entrainment, and synaptic signaling from the Kyoto Encyclopedia of Genes and Genomes pathway analysis and responded to corticosteroids, positive regulation of lipid transport, anterograde trans-synaptic signaling, and chemical synapse transmission from the Gene Ontology analysis. Based on protein-protein interaction network analysis of the DEGs, we identified neuroactive ligand-receptor interactions, circadian entrainment, and cholinergic synapse-related subclusters. Additionally, cell type and habenular regional expression of DEGs, evaluated using a recently published single-cell RNA sequencing study (GSE137478), strongly suggest that DEGs related to neuroactive ligand-receptor interaction and trans-synaptic signaling are highly enriched in medial habenular neurons. Taken together, our findings provide a valuable set of molecular targets that may play important roles in mediating the habenular response to stress and the onset of chronic stress-induced depressive behaviors.