The choroid plexuses (ChPs) are the main regulators of cerebrospinal fluid (CSF) composition and thereby also control the composition of a principal source of signaling molecules that is in direct contact with neural stem cells in the developing brain. The regulators of ChP development mediating the acquisition of a fate that differs from the neighboring neuroepithelial cells are poorly understood. Here, we demonstrate in mice a crucial role for the transcription factor Otx2 in the development and maintenance of ChP cells. Deletion of Otx2 by the Otx2-CreERT2 driver line at E9 resulted in a lack of all ChPs, whereas deletion by the Gdf7-Cre driver line affected predominately the hindbrain ChP, which was reduced in size, primarily owing to an increase in apoptosis upon Otx2 deletion. Strikingly, Otx2 was still required for the maintenance of hindbrain ChP cells at later stages when Otx2 deletion was induced at E15, demonstrating a central role of Otx2 in ChP development and maintenance. Moreover, the predominant defects in the hindbrain ChP mediated by Gdf7-Cre deletion of Otx2 revealed its key role in regulating early CSF composition, which was altered in protein content, including the levels of Wnt4 and the Wnt modulator Tgm2. Accordingly, proliferation and Wnt signaling levels were increased in the distant cerebral cortex, suggesting a role of the hindbrain ChP in regulating CSF composition, including key signaling molecules. Thus, Otx2 acts as a master regulator of ChP development, thereby influencing one of the principal sources of signaling in the developing brain, the CSF.
The transcription factor Otx2 regulates choroid plexus development and function.
Sex
View SamplesObjective: Physical exercise and vitamin E are considered effective treatments of nonalcoholic fatty liver and other metabolic diseases. However, vitamin E has also been shown to interfere with the adaptation to exercise training, in particular for the skeletal muscle. Here, we studied the hypothesis that vitamin E also interferes with the metabolic adaptation of the liver to acute exercise.
A Vitamin E-Enriched Antioxidant Diet Interferes with the Acute Adaptation of the Liver to Physical Exercise in Mice.
Sex, Specimen part
View SamplesHeterogeneous nuclear ribonucleoprotein (hnRNP) C1/C2 plays a pivotal role in vitamin D receptor (VDR) signaling by acting as a vitamin D response element (VDRE)-binding protein (VDRE-BP). Transcriptional regulation by active 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) involves occupancy of VDRE by VDRE-BP or 1,25(OH)2D3 bound-VDR. This relationship is disrupted by over-expression of VDRE-BP and can cause a form of human hereditary vitamin D-resistant rickets (HVDRR). DNA array analyses using B-cells from an HVDRR patient and matched control defined a sub-cluster of genes where 1,25(OH)2D3-regulated transcription was abrogated by over-expression of VDRE-BP. Amongst these, the DNA-damage-inducible transcript 4 (DDIT4), an inhibitor of mammalian target of rapamycin (mTOR) signaling, was also induced by 1,25(OH)2D3 in human osteoblasts.
Gene targeting by the vitamin D response element binding protein reveals a role for vitamin D in osteoblast mTOR signaling.
Sex, Specimen part, Subject
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microRNA cluster 106a~363 is involved in T helper 17 cell differentiation.
Sex
View SamplesCombined analysis of mRNA and miRNA transcriptoms revealed a complex network regulating major immune regulatory signaling pathways
microRNA cluster 106a~363 is involved in T helper 17 cell differentiation.
Sex
View SamplesEmbryonic mouse brain development involves a sequential differentiation of multipotent progenitor cells into neurons and glia. Using microarrays and large 2-D electrophoresis, we investigated the transcriptome and proteome of mouse brains at embryonic days 9.5, 11.5 and 13.5. During this developmental period, neural progenitor cells shift from proliferation to neuronal differentiation. As expected, we detected numerous expression changes between the time points investigated but interestingly, the rate of alteration was about 10% to 13% of all proteins and mRNAs during every two days of development. Furthermore, up- and downregulation was balanced. This was confirmed for two additional stages of development, embryonic day 16 and 18. We hypothesize that during embryonic development, the rate of protein expression alteration is rather constant due to a limitation of cellular resources such as energy, space and free water. The similar complexity found at the transcriptome and proteome level at all stages suggests, that changes in relative concentration of gene products rather than an increased number of gene products dominate throughout cellular differentiation. We found that metabolism and cell cycle related gene products were downregulated in expression when precursor cells switched from proliferation to neuronal differentiation (day 9.5 to 11.5), whereas neuron specific gene products were upregulated. A detailed analysis revealed their implication in differentiation related processes such as rearrangement of the actin cytoskeleton as well as Notch and Wnt signaling pathways.
Transcriptome and proteome analysis of early embryonic mouse brain development.
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View SamplesMuscle contraction during exercise is the major stimulus for the release of peptides and proteins (myokines) that are supposed to take part in the benefical adaptation to exercise. We hypothesize that application of an in vitro exercise stimulus as electric pulse stimulation (EPS) to human myotubes enables the investigation of the human muscle secretome in a clearly defined model. We applied EPS for 24 h to primary human myotubes and studied the whole genome-wide transcriptional response and as well as the release of candidate myokines. We observed 183 differentially regulated transcripts with fold-changes > 1.3. The transcriptional response resembles several properties of the in vivo situation in the skeletal muscle after endurance exercise, namely significant enrichment of pathways associated with interleukin and chemokine signaling, lipid metabolism, and anti-oxidant defense; notably without increased release of creatin kinase.
Cytokine response of primary human myotubes in an in vitro exercise model.
Sex, Specimen part, Subject
View SamplesThe invasion of activated fibroblasts represents a key pathomechanism in fibrotic diseases, carcinogenesis and metastasis. Here, invading fibroblasts contribute to fibrotic extracellular matrix (ECM) formation and the initiation, progression, or resistance of cancer, respectively. To construct a transcriptome-wide signature of fibroblast invasion, we used a multiplex phenotypic 3D invasion assay using murine lung fibroblasts. Microarray-based gene expression profiles of invading and non-invading fibroblasts were highly distinct: 1049 genes were differentially regulated (>1.5-fold). An unbiased pathway analysis (Ingenuity) identified a significant enrichment for the functional clusters invasion of cells, idiopathic pulmonary fibrosis (IPF) and metastasis. Particularly, matrix metalloprotease13 (MMP13), transforming growth factor (TGF)1, Caveolin1 (Cav1), Phosphatase and Tensin Homolog (Pten), and secreted frizzled-related protein1 (Sfrp1) were among the highest regulated genes. In silico analysis by Ingenuity predicted TGF1, epidermal growth factor (EGF), fibroblast growth factor2 (FGF2), and platelet-derived growth factor (PDGF)-BB to induce invasion. As such, these growth factors were tested in the 3D invasion assay and displayed a significant induction of invasion, thus validating the transcriptome profile. Accordingly, our transcriptomic invasion signature describes the invading fibroblast phenotype in unprecedented detail and provides a tool for future functional studies of cell invasion and therapeutic modulation thereof.
Validated prediction of pro-invasive growth factors using a transcriptome-wide invasion signature derived from a complex 3D invasion assay.
Sex
View SamplesCDKN1B (p27) was formally established as a tumor suppressor gene (tsg) following the identification of inactivating germline mutations in rats (MENX syndrome) and patients (MEN4 syndrome) developing multiple neuroendocrine tumors (NETs). MENX-affected rats are homozygous for the predisposing p27 mutation, suggesting a canonical tsg function. In contrast, mice heterozygous for a defective Cdkn1b allele are already predisposed to tumor formation (haploinsufficiency). We here report that heterozygous mutant rats (p27+/mut) develop the same NETs seen in the homozygous (p27mut/mut) animals but with slower progression. In the tumors of p27+/mut rats, the wild-type allele is neither lost nor silenced, implying that p27 is haploinsufficient for tumor suppression also in this model.
Characterization of neuroendocrine tumors in heterozygous mutant MENX rats: a novel model of invasive medullary thyroid carcinoma.
Age
View SamplesPheochromocytomas (PCC) are mostly benign tumors, amenable to complete surgical resection. However, 1017% of cases can become malignant, and once metastasized, there is no curative treatment for this disease. Given the need to identify effective therapeutic approaches for PCC, we evaluated the antitumor potential of the dual PI3K/mTOR inhibitor BEZ235 against these tumors. We employed an in vivo model of endogenous PCCs (MENX mutant rats), which closely recapitulate the human tumors. Mutant rats with PCCs were treated with 2 doses of BEZ235 (20 and 30 mg/kg), or with placebo, for 2 weeks. Treatment with BEZ235 induced cytostatic and cytotoxic effects on rat PCCs, which could be appreciated by both staining the tumors ex vivo with appropriate markers, and non-invasively by functional imaging (diffusion weighted-DW-MRI) in vivo.
Targeting PI3K/mTOR signaling exerts potent antitumor activity in pheochromocytoma in vivo.
Sex, Age, Specimen part, Treatment
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