Nicotine, acting through the neuronal nicotinic acetylcholine receptors (nAChR), can induce seizures in mice. We aimed to study brain transcriptional response to seizure and to identify genes whose expression is altered after nicotine-induced seizures. Whole brains of untreated mice were compared to brains one hour after seizure activity, using Affymetrix U74Av2 microaarays. Experimental groups included wild-type mice and both nicotine-induced seizures sensitive and resistant nAChR mutant mice. Each genotype group received different nicotine doses to generate seizures. This approach allowed the identification of significantly changed genes whose expression was dependent on seizure activity, nicotine administration or both, but not on the type of nAChR subunit mutation or the amount of nicotine injected. Significant expression changes were detected in 62 genes (p < 0.05, FDR correction). Among them, GO functional annotation analysis determined that the most significantly over-represented categories were of genes encoding MAP kinase phosphatases, regulators of transcription and nucleosome assembly proteins. In-silico bioinformatic analysis of the promoter regions of the 62 changed genes detected the significant enrichments of 16 transcription regulatory elements (TREs), creating a network of transcriptional regulatory responses to seizures. The TREs for ATF and SRF were most significantly enriched, supporting their association with seizure activity. Our data suggest that nicotine-induced seizure in mice is a useful model to study seizure activity and its global brain transcriptional response. The differentially expressed genes detected here can help understand the molecular mechanisms underlying seizures in animal models, and may also serve as candidate genes to study epilepsy in humans.
Expression changes in mouse brains following nicotine-induced seizures: the modulation of transcription factor networks.
Sex, Age, Treatment
View SamplesAging is accompanied by expression changes in multiple genes and the brain is one of the tissues most vulnerable to aging. Since the alpha7 nicotinic acetylcholine receptor (nAChR) subunit has been associated with neurodevelopmental disorders and cognitive decline during aging, we hypothesized that its absence might affect gene expression profiles in aged brains. To study whether transcriptional changes occur due to aging, alpha7 deficiency or both, we analyzed whole brain transcriptomes of young (8 week) and aged (2 year) alpha7 deficient and wild-type control mice, using Mouse Genome 430 2.0 microarray. Highly significant expression changes were detected in 47 and 1543 genes (after Bonferroni and FDR correction) in the brains of aged mice compared to young mice, regardless of their genotype. These included genes involved in immune system function and ribosome structure, as well as genes that were previously demonstrated as differentially expressed in aging human brains. Genotype-dependent changes were detected in only 3 genes, Chrna7 which encodes the alpha7 nAChR subunit, and two closely linked genes, likely due to a mouse background effect. Expression changes dependent on age-genotype interaction were detected in 207 genes (with a low significance threshold). Age-dependent differential expression levels were approved in all nine genes that were chosen for validation by real-time RT-PCR. Our results suggest that the robust effect of aging on brain transcription clearly overcomes the almost negligible effect of alpha7 nAChR subunit deletion, and that germline deficiency of this subunit has a minor effect on brain expression profile in aged mice.
The effects of aging vs. α7 nAChR subunit deficiency on the mouse brain transcriptome: aging beats the deficiency.
Age
View SamplesMicroRNAs (miRs) function primarily as post-transcriptional negative regulators of gene expression through binding to their mRNA targets. Reliable prediction of a miRs targets is a considerable bioinformatic challenge of great importance for inferring the miRs function. Sequence-based prediction algorithms have high false-positive rates, are not in agreement, and are not biological context specific. Here we introduce CoSMic (Context-Specific MicroRNA analysis), an algorithm that combines sequence-based prediction with miR and mRNA expression data. CoSMic differs from existing methodsit identifies miRs that play active roles in the specific biological system of interest and predicts with less false positives their functional targets. We applied CoSMic to search for miRs that regulate the migratory response of human mammary cells to epidermal growth factor (EGF) stimulation. Several such miRs, whose putative targets were significantly enriched by migration processes were identified. We tested three of these miRs experimentally, and showed that they indeed affected the migratory phenotype; we also tested three negative controls. In comparison to other algorithms CoSMic indeed filters out false positives and allows improved identification of context-specific targets. CoSMic can greatly facilitate miR research in general and, in particular, advance our understanding of individual miRs function in a specific context.
Context-specific microRNA analysis: identification of functional microRNAs and their mRNA targets.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gaucher disease: transcriptome analyses using microarray or mRNA sequencing in a Gba1 mutant mouse model treated with velaglucerase alfa or imiglucerase.
Age, Specimen part, Treatment
View SamplesThe comparative whole genome transcriptome effects of two similar pharmaceuticals, imig or vela, on a Gaucher disease mouse model, 9V/null, were evaluated by two commonly used platforms, mRNA-Seq and microarray. Also, statistical methods, DESeq and edgeR for mRNA-Seq and Mixed Model ANOVA for microarray, were compared for differential gene expression detection. The biological pathways were similar between two platforms. Cell growth and proliferation, cell cycle, heme metabolism, and mitochondrial dysfunction were the most altered functions associated with the disease process. Although the two biopharmaceuticals have a very similar structure and function, imig- and vela- treatment in the mice differentially affected disease-specific pathways indicating the action of the two drugs on the disease process in the visceral tissues of Gaucher mouse model differ significantly at the molecular level. This study provides a comprehensive comparison between the two platforms (mRNA-Seq and microarray) for gene expression analysis and addresses the contribution of the different methods involved in the analysis of such data. The results also provide insights into the differential molecular effects of two similar biopharmaceuticals for Gaucher disease treatment Overall design: 9V/null mice (Gaucher mouse model) were injected weekly via tail vein with 60U/kg/wk of imig or vela for 8 wks. Control 9V/null mice were injected with same volume of saline. Wt mice were untreated. Age and strain matched mice were used for the study. Also, statistical methods, DESeq and edgeR for mRNA-Seq and Mixed Model ANOVA for microarray, were compared for differential gene expression detection. Cell growth and proliferation, cell cycle, heme metabolism, and mitochondrial dysfunction were the most altered functions associated with the disease process. The results also provide insights into the differential molecular effects of two similar biopharmaceuticals for Gaucher disease treatment.
Gaucher disease: transcriptome analyses using microarray or mRNA sequencing in a Gba1 mutant mouse model treated with velaglucerase alfa or imiglucerase.
Age, Specimen part, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gaucher disease: transcriptome analyses using microarray or mRNA sequencing in a Gba1 mutant mouse model treated with velaglucerase alfa or imiglucerase.
Age, Specimen part, Treatment
View SamplesGaucher disease type 1 is an inborn error of metabolic disease with the defective activity of the lysosomal enzyme acid b-glucosidase (GCase). Enzyme replacement/reconstitution therapy (ERT), infusions with purified recombinant GCases, is efficacious in reversing hematologic, hepatic, splenic, and bony disease manifestations in Gaucher type 1 patients. However, the tissue specific molecular events in Gaucher disease and their response to therapy are not known yet. To explore the molecular events underlying GCase treatment, we evaluated the tissue-specific gene expression profiles and molecular responses in our Gaucher disease mouse model, which were treated with two FDA approved commercially available GCases, imiglucerase (imig) and velaglucerase alfa (vela). Using microarray and mRNA-Seq techniques, differentially expressed genes (DEGs) were identified in the spleen and liver by the direct comparison of imig- vs. vela- treated mice. Among them three gene expression networks were derived from these spleens: 1) cell division/proliferation, 2) hematopoietic system and 3) inflammatory/macrophage response. Our study showed the occurrence of differential molecular pathophysiologic processes in the mice treated with imig compared with vela even though these two biosimilars had the same histological and biochemical efficacy Overall design: 9V/null mice (Gaucher mouse model) were injected weekly via tail vein with 60U/kg/wk of imig or vela for 8 wks. To understand the molecular events underlying GCase treatment, we evaluated the tissue-specific gene expression profiles and molecular responses in our Gaucher disease mouse model, which were treated with two FDA approved commercially available GCases, imiglucerase (imig) and velaglucerase alfa (vela).
Gaucher disease: transcriptome analyses using microarray or mRNA sequencing in a Gba1 mutant mouse model treated with velaglucerase alfa or imiglucerase.
Age, Specimen part, Treatment, Subject
View SamplesAbstract Background. The cellular effects of androgen are transduced through the androgen receptor, which controls the expression of genes that regulate biosynthetic processes, cell growth, and metabolism. Androgen signaling also impacts DNA damage signaling through mechanisms involving gene expression and transcription-associated DNA damaging events. Defining the contributions of androgen signaling to DNA repair is important for understanding androgen receptor function, and it also has important translational implications. Methods. We generated RNA-seq data from multiple prostate cancer lines and used bioinformatic analyses to characterize androgen-regulated gene expression. We compared the results from cell lines with gene expression data from prostate cancer xenografts, and patient samples, to query how androgen signaling and prostate cancer progression influences the expression of DNA repair genes. We performed whole genome sequencing to help characterize the status of the DNA repair machinery in widely used prostate cancer lines. Finally, we tested a DNA repair enzyme inhibitor for effects on androgen-dependent transcription. Results. Our data indicates that androgen signaling regulates a subset of DNA repair genes that are largely specific to the respective model system and disease state. We identified deleterious mutations in the DNA repair genes RAD50 and CHEK2. We found that inhibition of the DNA repair enzyme MRE11 with the small molecule mirin inhibits androgen-dependent transcription and growth of prostate cancer cells. Conclusions. Our data supports the view that crosstalk between androgen signaling and DNA repair occurs at multiple levels, and that DNA repair enzymes in addition to PARPs, could be actionable targets in prostate cancer. Overall design: RNA was extracted from PC3-AR, VCaP, and LNCaP cells under untreated and androgen (2 nM, R1881) treated conditions. A total of 21 samples were sequenced with 3 replicates for each condition.
Genomic analysis of DNA repair genes and androgen signaling in prostate cancer.
Cell line, Subject
View SamplesSplenocytes from lymphoreplete, unmanipulated mice were analyzed for basal mRNA levels. We hypothesized, based on previous data from our lab and others, that many cytokine/inflammatory response genes would show an increase from na誰ve CD5lo<CD5hi<Virtual memory. Overall design: mRNA was analyzed from mouse splenocytes separated into na誰ve CD5lo, na誰ve CD5hi, and virtual memory cells. Mice were lymphoreplete and unmanipulated.
Virtual memory T cells develop and mediate bystander protective immunity in an IL-15-dependent manner.
Cell line, Subject
View SamplesPre-stimulation of MDMs with LPS (signals via MyD88 and TRIF dependent pathways) and PolyI:C (signals via a TRIF dependent pathway) leads to a reduced viral infection. In contrast, pre-stimulation with P3C (signals via MyD88 dependent pathway) does not lead to a reduced viral infection. This microarray was performed to find genes that are specifically upregulated in LPS and PolyI:C stimulated MDMs but not P3C stimulated MDMs. So to give us leads into the mechanism involved in the reduction of viral infection.
Bacterial lipopolysaccharide inhibits influenza virus infection of human macrophages and the consequent induction of CD8+ T cell immunity.
Specimen part, Treatment, Subject
View Samples