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GSE30012
Mus musculus
5 Downloadable Samples
Description
MicroRNAs (miRNAs) post-transcriptionally regulate the expression of thousands of distinct mRNAs. While some regulatory interactions help to maintain basal cellular functions, others are likely relevant in more specific settings, such as response to stress. Here we describe such a role for the mir-290-295 cluster, the dominant miRNA cluster in mouse embryonic stem cells (mESCs). Examination of a target list generated from bioinformatic prediction, as well as expression data following miRNA loss, revealed strong enrichment for apoptotic regulators, two of which we validated directly: Caspase 2, the most highly conserved mammalian caspase, and Ei24, a p53 transcriptional target. Consistent with these predictions, mESCs lacking miRNAs were more likely to initiate apoptosis following genotoxic exposure to gamma irradiation or doxorubicin. Knockdown of either candidate partially rescued this pro-apoptotic phenotype, as did transfection of members of the mir-290-295 cluster. These findings were recapitulated in a specific mir-290-295 deletion line, confirming that they reflect miRNA functions at physiological levels. In contrast to the basal regulatory roles previously identified, the pro-survival phenotype shown here may be most relevant to stressful gestations, where pro-oxidant metabolic states induce DNA damage. Similarly, this cluster may mediate chemotherapeutic resistance in a neoplastic context, making it a useful clinical target.
Publication Title
A latent pro-survival function for the mir-290-295 cluster in mouse embryonic stem cells.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 22 Downloadable Samples
Description
The purpose was to determine AcP- and AcPb-dependent gene responses to IL-1 by virally-reconstituting AcP-deficient mouse embryonic cortical neurons with CD25 (control), full length AcP, AcPb or the combination of both. A control population was transduced with a CD25-expressing virus. Half the samples were stimulated with IL-1-beta for four hours, RNA was analyzed by microarray.
Publication Title
A central nervous system-restricted isoform of the interleukin-1 receptor accessory protein modulates neuronal responses to interleukin-1.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
Description
CD4+ T cell help is critical for optimal CD8+ T cell expansion after priming in many experimental systems. However, a role for CD4+ T cells in regulating the initial steps of CD8+ T cell effector differentiation is not well established. Here we demonstrate that absence of CD4+ T cells at the time of replication-incompetent adenovirus vector immunization of C57BL/6 mice led to immediate CD8+ T cell dysfunction characteristic of exhaustion at the first detectable timepoints as well as impaired expansion of antigen-specific CD8+ T cells. The absence of CD4+ T cell help resulted in antigen-specific CD8+ T cells that had reduced ex vivo cytotoxicity and decreased capacity to produce IFN- and TNF-. CD8+ T cells primed in the absence of CD4+ T cells expressed elevated levels of the inhibitory receptors PD-1, LAG-3, and Tim-3, and these cells exhibited transcriptomic exhaustion profiles by gene set enrichment analysis. This dysfunctional state was imprinted within 3 days of immunization and could not be reversed by provision of CD4+ T cell help after priming. Partial rescue of unhelped CD8+ T cell expansion and effector differentiation could be achieved by PD-1 pathway blockade or recombinant IL-2 administration.
Publication Title
Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 23 Downloadable Samples
Description
Cardiac hypertrophy can lead to heart failure, and is induced either by physiological stimuli eg postnatal development, chronic exercise training or pathological stimuli eg pressure or volume overload. Majority of new therapies for heart failure has mixed outcomes. A combined mouse model and oligo-array approach are used to examine whether phosphoinositide 3-kinase (p110-alpha isoform) activity is critical for maintenance of cardiac function and long-term survival in a setting of heart failure. The significance and expected outcome are to recognise genes involved in models of heart failure ie pathological- vs physiology-hypertrophy, and examine the molecular mechanisms responsible for such activity.
Publication Title
PI3K(p110 alpha) protects against myocardial infarction-induced heart failure: identification of PI3K-regulated miRNA and mRNA.
Sample Metadata Fields
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