Filters
Organism
Technology
Platform
GSE16380
Mus musculus
8 Downloadable Samples
Description
CCAAT/enhancer binding protein beta (C/EBPb) is a member of a family of highly conserved transcription factors that regulates numerous genes involved in proliferation and differentiation in a variety of tissues. C/EBPb is deregulated in human breast cancer and germline deletion of this gene results in multiple defects in mammary gland development. We hypothesized that C/EBPb regulates mammary stem cell self-renewal, maintenance and/or differentiation through the regulation of multiple target genes that coordinate mammary gland development. Utilizing both a germline knockout mouse model and a conditional knockout strategy, we demonstrated that mammosphere formation was significantly decreased in C/EBPb-deficient mammary epithelial cells (MECs). The ability of C/EBPb-deleted MECs to regenerate the mammary gland in vivo was severely impaired when transplanted at limiting dilution. Furthermore, serial transplantation of C/EBPb-null mammary tissue resulted in decreased outgrowth potential when compared to wildtype, and an early senescence phenotype. Flow cytometric analysis revealed that C/EBPb-null MECs contain a lower frequency of repopulating stem cells accompanied by an increase in committed, differentiated luminal cells as compared to wildtype. Microarray analysis of stem/progenitor cell populations was performed and revealed an alteration in cell fate specification in C/EBPb-null glands, exemplified by the aberrant expression of basal markers in the luminal cell compartment. Collectively, our studies demonstrate that C/EBPb is a critical regulator of mammary stem cell differentiation, and an important determinant of luminal cell fate specification.
Publication Title
CCAAT/enhancer binding protein beta regulates stem cell activity and specifies luminal cell fate in the mammary gland.
Alternate Accession IDs
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 7 Downloadable Samples
Description
Primordial genomic challenge compromises embryonic development and survival, and surveillance of deployed transcriptional programs may provide an early opportunity to forecast phenotype abnormalities. Here, comparisons between wild-type and calreticulin-ablated embryonic stem cells revealed transcriptome shifts precipitated by calreticulin loss. Bioinformatic analysis identified down and up-regulation in 1187 and 418 genes, respectively. Cardiovascular development precedes other organogenic programs, and examination of cardiogenic genes revealed a map of calreticulin-calibrated expression profiles that encompass the developmental regulators, Ccnd1, Ccnd2 and Notch1. Interrogation of primary function in the resolved network forecasted abnormalities during myocardial development. Whole embryo magnetic resonance imaging, verified by pathoanatomical analysis, diagnosed prominent ventricular septal defect. Correlation clustering and network resolution of probesets associated with protein folding/chaperoning and calcium handling demonstrated 14 and 19 genes, respectively, modulated by calreticulin deficiency. Calreticulin deletion provoked ontological re-prioritization of gene expression, molecular transport and protein trafficking that translated into multiple subcellular functional outcomes. Individual stem cell-derived cardiomyocytes lacking calreticulin demonstrated a disorganized contractile apparatus with mitochondrial paucity and architectural aberrations. Thus, bioinformatic deconvolution of primordial embryonic stem cell transcriptomes enables predictive phenotyping of defective developmental networks that coalesce from complex systems biology hierarchies.
Publication Title
Decoded calreticulin-deficient embryonic stem cell transcriptome resolves latent cardiophenotype.
Alternate Accession IDs
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
Description
The mammalian gastrointestinal tract harbors thousands of bacterial species that include symbionts as well as potential pathogens. The immune responses that limit access of these bacteria to underlying tissue remain poorly defined.
Publication Title
Gammadelta intraepithelial lymphocytes are essential mediators of host-microbial homeostasis at the intestinal mucosal surface.
Alternate Accession IDs
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 9 Downloadable Samples
Description
Epithelial tumor cells (E) underwent EMT in vivo in FVB/N mice generating mesenchymal tumors. Mesenchymal cell lines (M1-M4) were each derived from a different mouse. This study compares gene expression between these two different tumor types.
Publication Title
Immune-induced epithelial to mesenchymal transition in vivo generates breast cancer stem cells.
Alternate Accession IDs
Sample Metadata Fields
No sample metadata fields
View Samples