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GSE13948
Mus musculus
21 Downloadable Samples
Description
Antagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver
Publication Title
Antagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 3 Downloadable Samples
Description
Sialic acids on vertebrate cell surfaces mediate many biological roles. Altered expression of certain sialic acid types or their linkages can have prognostic significance in human cancer. A classic but unexplained example is enhanced 2-6-sialylation on N-glycans, resulting from over-expression of the Golgi enzyme -galactoside:2-6-sialyltransferase (ST6Gal-I). Previous data supporting a role for the resulting Sia2-3Gal1-4GlcNAc (Sia6LacNAc) structure in tumor biology were based on in vitro studies in transfected carcinoma cells, in which increased Sia6LacNAc on 1-integrins enhanced their binding to ligands, and stimulated cell motility. Here we examine for the first time the in vivo role of the ST6Gal-I enzyme in the growth and differentiation of spontaneous mammary cancers in mice transgenic for an MMTV-promoter-driven polyoma-middle-T antigen, a tumor in which beta1-integrin function is important for tumorigenesis, and in maintaining the proliferative state of tumor cells. Tumors induced in St6gal1 null animals were more differentiated in comparison to those in the wild-type background, both by histological analysis and by protein expression profiles. Furthermore, we show the St6gal1 null tumors have selectively altered expression of genes associated with focal adhesion signaling, and have decreased phosphorylation of FAK, a downstream target of 1-integrins. This first in vivo evidence for a role of ST6Gal-I in tumor progression was confirmed using a novel approach, which conditionally restored St6gal1 in cell lines derived from the null tumors. These findings indicate a role for ST6Gal-I as a mediator of tumor progression, with its expression causing a less differentiated phenotype, via enhanced 1-integrin function.
Publication Title
alpha 2-6-Linked sialic acids on N-glycans modulate carcinoma differentiation in vivo.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
Description
A surge of luteinizing hormone (LH) from the pituitary gland triggers ovulation, oocyte maturation, and luteinization for successful reproduction in mammals. Since the signaling molecules RAS and ERK1/2 are activated by a LH surge in granulosa cells of preovulatory follicles, we disrupted Erk1/2 in mouse granulosa cells and provide in vivo evidence that these kinases are necessary for LH-induced oocyte resumption of meiosis, ovulation, and luteinization. In addition, biochemical analyses and selected disruption of the Cebpb gene in granulosa cells demonstrate that C/EBP is a critical downstream mediator of ERK1/2 activation. These mouse models provide in vivo systems in which to define the context specific and molecular mechanisms by which granulosa cells respond to LH and these mechanisms are relevant to the regulation of human fertility and infertility.
Publication Title
MAPK3/1 (ERK1/2) in ovarian granulosa cells are essential for female fertility.
Sample Metadata Fields
Age, Specimen part
View Samples- Mus musculus
- 24 Downloadable Samples
Description
Background and Aims: In the interleukin-10-deficient (Il10-/-) mouse model of IBD, 10 quantitative trait loci (QTL) have been shown to be associated with colitis susceptibility by linkage analyses on experimental crosses of highly susceptible C3H/HeJBir (C3Bir)-Il10-/- and partially resistant C57BL/6J (B6)-Il10-/- mice. The strongest locus (C3Bir-derived cytokine deficiency-induced colitis susceptibility [Cdcs]1 on Chromosome [Chr] 3) controlled multiple colitogenic subphenotypes and contributed the vast majority to the phenotypic variance in cecum and colon. This was demonstrated by interval-specific Chr 3 congenic mice wherein defined regions of Cdcs1 from C3Bir or B6 were bred into the IL-10-deficient reciprocal background and altered the susceptible or resistant phenotype. Furthermore, this locus likely acts by inducing innate hypo- and adaptive hyperresponsiveness, associated with impaired NFB responses of macrophages. The aim of the present study was to dissect the complexity of Cdcs1 by further development and characterization of reciprocal Cdcs1 congenic strains and to identify potential candidate genes in the congenic interval. Material and Methods: In total, 15 reciprocal congenic strains were generated from Il10-/- mice of either C3H/HeJBir or C57BL/6J backgrounds by 10 cycles of backcrossing. Colitis activity was monitored by histological grading. Candidate genes were identified by fine mapping of congenic intervals, sequencing, microarray analysis and a high-throughput real-time RT-PCR approach using bone marrow-derived macrophages. Results: Within the originally identified Cdcs1-interval, three independent regions were detected that likely contain susceptibility-determining genetic factors (Cdcs1.1, Cdcs1.2, and Cdcs1.3). Combining results of candidate gene approaches revealed Fcgr1, Cnn3, Larp7, and Alpk1 as highly attractive candidate genes with polymorphisms in coding or regulatory regions and expression differences between susceptible and resistant mouse strains. Conclusions: Subcongenic analysis of the major susceptibility locus Cdcs1 on mouse chromosome 3 revealed a complex genetic structure. Candidate gene approaches revealed attractive genes within the identified regions with homologs that are located in human susceptibility regions for IBD.
Publication Title
Cdcs1 a major colitis susceptibility locus in mice; subcongenic analysis reveals genetic complexity.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 25 Downloadable Samples
Description
The generation of specific types of neurons from stem cells offers important opportunities in regenerative medicine. However, future applications and proper verification of cell identities will require stringent ways to generate homogenous neuronal cultures. Here we show that under permissive culturing conditions individual transcription factors can induce a desired neuronal lineage from virtually all expressing cells by a mechanism resembling developmental binary cell fate switching. Such efficient selection of cell fate resulted in remarkable cellular enrichment that enabled global gene expression validation of generated neurons and identification of novel features in the studied cell lineages. Several sources of stem cells have a limited competence to differentiate into e.g. dopamine neurons. However, we show that the combination of factors that normally promote either regional or dedicated neuronal specification can overcome limitations in cellular competence and promote efficient reprogramming also in more remote neural contexts, including human neural progenitor cells.
Publication Title
Transcription factor-induced lineage selection of stem-cell-derived neural progenitor cells.
Sample Metadata Fields
Specimen part, Cell line
View Samples