Transcription profiling of yeast Med2, Med3, Med18, Med20 deletion mutants and with a C-terminal truncation of Med8
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ABSTRACT: We made deletions of Med2, Med3, Med18, Med20 and a C-terminal truncation of Med8. We expression profiled the mutants against a common reference.
Project description:In order to study the physiological consequences of a high-copper diet on hepatic gene expression, 6 mM CuCl2 was added to the drinking water for a period of 1 month. After this period, livers of seven control mice and eight copper-treated mice were isolated and were subjected to microarray analysis and copper measurements. The hepatic gene expression profile of copper-treated mice was compared to non-treated mice using a pooled reference.
Project description:Nine time points for microarray analysis were chosen to study early and late transcriptional responses in copper metabolism upon copper overload in HepG2 cells. Samples of copper-treated cells were hybridized using non-treated samples as a reference.
Project description:A gene expression study using microarray analysis was performed to elucidate the underlying mechanism leading to embryonic lethality in homozygous Commd1 null (Commd1-/-) mouse embryos. A gene expression profile of 9.5 dpc Commd1-/- embryos were generated and were compared to a gene expression profile of both 8.5 dpc and 9.5 dpc normal embryos.
Project description:The PI3K-PKB/c-akt-FOXO signalling network provides a major intracellular hub for regulation of cell proliferation, survival and stress resistance1. Here we report a novel function for FOXO transcription factors in regulating autophagy through modulation of intracellular glutamine levels. To identify novel transcriptional targets of this module we performed an unbiased microarray analysis after conditional activation of the key components PI3K, PKB, FOXO3 and FOXO4. Utilising this global pathway approach we identified glutamine synthetase (GS) as being transcriptionally regulated by PI3K-PKB-FOXO signalling. FOXO-mediated increase in GS expression specifically induced glutamine production independently of cell type, and this was evolutionary conserved. FOXO activation resulted in mTOR inhibition by preventing the translocation of mTOR to lysosomal membranes, which was dependent on GS activity. Increased GS activity resulted in increased autophagosome turnover as measured by LC3 lipidation, p62 degradation, and confocal imaging of LC3, p62, WIPI-1, ULK2 and Atg12. Inhibition of FOXO3-mediated autophagy resulted in increased apoptosis, suggesting that the induction of autophagy by FOXO3-mediated upregulation of GS is important for cellular survival. These findings reveal a novel signalling network that can directly modulate autophagy through regulation of glutamine metabolism. conditional activation of foxo3 and foxo4 were followed in a timeseries. Each timepoint consists of 4 independent replicates, labeled with either cy3 or cy5 and put on array against time0 as reference.
Project description:Meso-diencephalic dopaminergic (mdDA) neurons are critical for motor control and cognitive functioning and their loss or dysfunction is associated with disorders such as Parkinson’s disease (PD), schizophrenia and addiction. However, relatively little is known about the molecular mechanisms underlying mdDA neuron development and maintenance. Here, we determined the spatiotemporal map of genes involved in the development of mdDA neurons to gain further insights into their molecular programming. Genome-wide gene expression profiles of the developing ventral mesencephalon (VM) were compared at different developmental stages leading to the identification of novel regulatory roles of neuronal signaling through nicotinic acthylcholine receptors (Chrna6 and Chrnb3 subunits) and the identification of novel transcription factors (OC1 and 2)) involved in the generation of mdDA neuronal field. We show here that Pitx3 in cooperation with Nurr1 are the critical components in the activation of the Chrna6 and b3 subunits in mdDA neurons. Furthermore, we provide evidence of two divergent regulatory pathways resulting in the expression of Chrna6 and Chrnb3 respectively. Embryonic ventral midbrain (VM) tissue was used to generate RNA samples for microarray analysis. Each sample consists of pooled RNA from three embryonic VMs, and is hybridized twice (in both dye orientations) against a common reference RNA (KC001-ref) consisting of pooled RNA from adult VMs. Each embryonic stages E10.5, E11.5, E12.5 and E13.5 is analysed from three independant samples.
Project description:This SuperSeries is composed of the following subset Series: GSE35701: CP001: Modulation of glutamine metabolism by the PI3K-PKB/c-akt-FOXO network regulates autophagy GSE35703: CP003: Modulation of glutamine metabolism by the PI3K-PKB/c-akt-FOXO network regulates autophagy Refer to individual Series
Project description:Contains gene expression profiles of yeast single and double deletion mutants of gene-specific transcription factors. Genetic interactions were studied by comparing gene expression changes of double mutants with gene expression changes in the respective single mutants. Pairs of gene-specific transcription factors were chosen based on previous evidence for epistasis, including synthetic genetic interactions as well as common DNA binding. Two channel microarrays were used. RNA isolated from a large amount of wt yeast from a single culture was used as a common reference. This common reference was used in one of the channels for each hybridization and used in the statistical analysis to obtain an average expression-profile for each deletion mutant relative to the wt. Two independent cultures were hybridized on two separate microarrays. For the first hybridization the Cy5 (red) labeled cRNA from the deletion mutant is hybridized together with the Cy3 (green) labeled cRNA from the common reference. For the replicate hybridization, the labels are swapped. Each gene is represented twice on the microarray, resulting in four measurements per mutant. Using the Erlenmeyer growth protocol up to five deletion strains were grown on a single day. In the tecan platereader, up to eleven deletion strains could be grown on a single day. Wt cultures were grown parallel to the deletion mutants to assess day-to-day variance.
Project description:Objective: Aging and early degeneration of the intervertebral disc (IVD) involves the substition of notochordal cells (NCs) in the nucleus pulposus (NP) by chondrocyte-like cells (CLCs). This study investigated the gene expression profiles involved in this process using NP tissue from both non-chondrodystrophic and chondrodystrophic dogs, a species with naturally occuring IVD degeneration. Methods: Dual channel DNA microarrays were used to compare 1) healthy NP tissue, 2) NP tissue with a mixed population of NCs and CLCs, and 3) NP tissue containing solely CLCs. Canonical Wnt-signaling was validated using qPCR of relevant Wnt target genes. Caveolin-1, a known regulator of canonical Wnt signaling, was investigated further in tissue sections using qPCR and immunohistochemistry, and in cultured NCs by qPCR and immunofluorescence. Also, the NP of 3-month-old caveolin-1 knock-out mice was histopathologically evaluated and compared with wild type mice of the same age. Results: Early IVD degeneration involved significant regulations in numerous pathways, such as extracellular matrix remodeling, Bone Morphogenetic Protein- , and Wnt/beta-catenin-signaling. With regard to Wnt/beta-catenin signaling, axin2 gene expression was significantly higher in chondrodystrophic dogs compared with non-chondrodystrophic dogs. IVD degeneration involved significant downregulation of axin2 gene expression and caveolin-1 gene and protein expression. NCs showed abundant caveolin-1 expression in vivo and in vitro, whereas CLCs did not. The NP of 3-month-old WT mice were rich in viable NCs, whereas the NPs of 3-month-old caveolin-1 knock-out mice contained chondroid-like matrix with small, rounded cells, the majority of which showed morphological signs of apoptosis. Conclusions: Aging and the onset of degeneration of the IVD involve significant downregulation of canonical Wnt signaling and caveolin-1, which appears to be essential in the physiology and preservation of NCs. DNA microarrays were used to compare nucleus palposus (NP) tissue of healthy and chondrodystrophic individuals. Furthermore, the situation of the tissue was divided into three stages: NCR: notochordal cell(NC) rich; CR: tissue containing solely chondrocyte-like-cells (CLC) and T: tissue with a mixed population of NCs and CLCs. Comparisons were analysed on a 2-color platform against a common reference sample, consisting of a multitude of canine organs, including liver, spleen, kidney, lung, hart, intestine and bone.