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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
- 78 Downloadable Samples
Description
Polyinosinic:polycytidylic acid (poly I:C) is a synthetic analogue of double-stranded (ds)RNA, a molecular pattern associated with viral infections, that is used to exacerbate inflammation in lung injury models. Despite its frequent use, there are no detailed studies of the responses elicited by a single topical administration of poly I:C to the lungs of mice. Our data provides the first demonstration that the molecular responses in the airways induced by poly I:C correlate to those observed in the lungs of COPD patients. These expression data also revealed three distinct phases of response to poly I:C, consistent with the changing inflammatory cell infiltrate in the airways. Poly I:C induced increased numbers of neutrophils and NK cells in the airways, which were blocked by CXCR2 and CCR5 antagonists, respectively. Using gene set variation analysis on representative data sets, gene sets defined by poly I:C-induced DEGs were enriched in the molecular profiles of chronic obstructive pulmonary disease (COPD), but not idiopathic pulmonary fibrosis patients. Collectively, these data represent a new approach for validating the clinical relevance of preclinical animal models and demonstrate that a dual CXCR2/CCR5 antagonist may be an effective treatment for COPD patients.
Publication Title
Double-stranded RNA induces molecular and inflammatory signatures that are directly relevant to COPD.
Sample Metadata Fields
Sex, Specimen part, Time
View Samples- Mus musculus
- 111 Downloadable Samples
Description
Genomic profiling of bleomycin- and saline-treated mice across 7 timepoints (1, 2, 7, 14, 21, 28, 35 days post treatment) was carried out in C57BL6/J mice to determine the phases of response to bleomycin treatment which correspond to onset of active pulmonary fibrosis.
Publication Title
Bleomycin induces molecular changes directly relevant to idiopathic pulmonary fibrosis: a model for "active" disease.
Sample Metadata Fields
Sex, Specimen part, Treatment, Time
View Samples- Mus musculus
- 4 Downloadable Samples
Description
Following infection with LCMV, CD4+ SMARTA TCR transgenic cells (specific for the gp61-80 epitope of the LCMV glycoprotein) rapidly expand, become effector cells, and go on to form a long-lived memory population. Following infection with a recombinant Listeria monocytogenes expressing the LCMV epitope gp61-80, SMARTA cells also expand but display defective effector differentiation and fail to form memory. In an attempt to understand the signals required for CD4 T cell memory differentiation, we compared gene expression by SMARTA cells at the peak of the primary response following either Lm-gp61 or LCMV infection.
Publication Title
Rapid culling of the CD4+ T cell repertoire in the transition from effector to memory.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 65 Downloadable Samples
Description
It is widely believed that the carcinogenic action of ionizing radiation is due to targeted DNA damage and resulting mutations, but there is also substantial evidence that non-targeted radiation effects alter epithelial phenotype and the stromal microenvironment. Activation of transforming growth factor 1 (TGF) is a non-targeted radiation effect that mediates cell fate decisions following DNA damage and regulates microenvironment composition; it could either suppress or promote cancer. We asked if such non-targeted radiation effects contribute to carcinogenesis by using a novel radiation chimera model. Unirradiated Trp53 null mammary epithelium was transplanted to the mammary stroma, previously divested of endogenous epithelia, of mice previously exposed to a single low (10 -100 cGy) radiation dose. By 300 days, 100% of transplants in irradiated hosts at either 10 or 100 cGy had developed Trp53 null breast carcinomas compared to 54% in unirradiated hosts. Tumor growth rate was also increased by high, but not low, dose host irradiation. In contrast, irradiation of Tgfb1 heterozygote mice prior to transplantation failed to decrease tumor latency, or increase growth rate at any dose. Host irradiation significantly reduced the latency of invasive ductal carcinoma compared to spindle cell carcinoma. However, irradiation of either host genotype significantly increased the frequency of estrogen receptor negative tumors. These data demonstrate two concepts critical to understanding radiation risks. First, non-targeted radiation effects can significantly promote the frequency and alter the features of epithelial cancer. Second, radiation-induced TGF activity is a key mechanism of tumor promotion.
Publication Title
Radiation acts on the microenvironment to affect breast carcinogenesis by distinct mechanisms that decrease cancer latency and affect tumor type.
Sample Metadata Fields
Age, Specimen part
View Samples