E-MTAB-3001
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ABSTRACT:
PROVIDER: E-MTAB-3001 | ExpressionAtlas | 2018-06-04
REPOSITORIES: ExpressionAtlas
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Project description:The genome-wide transcriptional response of S. cerevisiae cells upon transfer to carbon-limited or carbon-limited and metformin supplemented media is investigated. DHO strain (BY4742 background) was cultivated batch-wise in SDC media at 30C and 180 rpm up to mid-exponential phase (OD600 ~ 0.6). The cells of the main culture were divided in three aliquots at the mid-exponential phase, centrifuged at 6000 rpm for 5 min, washed twice with deionized and distilled sterile water prior to their transfer to the treatment media. Treatment media comprised of SDC + 0.25% glucose for the C-lim control case and SDC +0.25%glucose + 1.66% metformin for the Met case. Control data for the reference condition (glucose limitation) is derived from E-MTAB-3001. Sample collection for transcriptional profiling was done at the 2nd hour of the transfer. The experiments were carried out in biological triplicates.
2019-07-21 | E-MTAB-6847 | biostudies-arrayexpress
Project description:The genome-wide transcriptional response of S. cerevisiae cells upon transfer to carbon-limited or metformin supplemented media is investigated. DHO strain (BY4742 background) was cultivated batch-wise in SDC media at 30C and 180 rpm up to mid-exponential phase (OD600 ~ 0.6). The cells of the main culture were divided in three aliquots at the mid-exponential phase, centrifuged at 6000 rpm for 5 min, washed twice with deionized and distilled sterile water prior to their transfer to the treatment media. Treatment media comprised of fresh SDC (2% glucose) for the control case, SDC + 0.25% glucose for the C-lim case and SDC + 1.66% metformin for the Met case. Samples collection for transcriptional profiling was done at the 2nd hour of the transfer. The experiments were carried out in biological triplicates.
2015-04-30 | E-MTAB-3001 | biostudies-arrayexpress
Project description:Transcriptional response of S. cerevisiae to metformin treatment in carbon-limited medium
2018-06-04 | E-MTAB-6847 | ExpressionAtlas
Project description:The genome-wide transcriptional response of S. cerevisiae cells upon transfer to methionine-restricted media is investigated. DHO strain (BY4742 background) was cultivated batch-wise in SDC media at 30C and 180 rpm up to mid-exponential phase (OD600 ~ 0.6). The cells of the main culture were divided in three aliquots at the mid-exponential phase, centrifuged at 6000 rpm for 5 min, washed twice with deionized and distilled sterile water prior to their transfer to the treatment media. Treatment media comprised of SDC + 0.75% methionine for the methionine-restricted case while SDC is used for the control case. Sample collection for transcriptional profiling was done at the 2nd hour of the transfer. The experiments were carried out in biological triplicates.
2024-01-01 | E-MTAB-12860 | biostudies-arrayexpress
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Galpha protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Keywords: Saccharomyces cerevisiae, nitrogen starvation, maltose, pseudohyphal differentiation, yeast, expression profiling
2007-12-21 | GSE7820 | GEO
Project description:The Warburg effect, consisting of increased glucose uptake and glycolysis, provides metabolic energy as well as cellular building blocks for tumor growth. Inhibition of the Warburg effect with 2-deoxyglucose (2DG) has been explored in clinical trials with limited efficacy. Blockage of glycolysis can induce autopahgy resulting in alternative energy generation through oxidative phosphorylation providing a potential bypass of the effects of inhibition of glycolysis. Here in we demonstrate that activation of AMPK, as a consequence of energetic stress, induces mitochondrial energy production potentially bypassing the effects of glycolysis inhibition. We thus combined blockage of glycolysis by 2DG with inhibition of the electron transfer complex I (ETC1) in the mitochondria with the clinically applicable antidiabetic drug metformin. The combination resulted in activation of AMPK and autopahgy that however rendered eventual depletion of ATP and cell death. Furthermore, combined inhibition of glycolysis and mitochondrial respiration inhibited tumor growth and markedly decreased metastatic capacity in vivo. In order to understand the mechanism of these metabolic inhibitors, we performed whole genome transcriptional analysis. Human SK-4 esophageal cancer cell lines were treated with 5 different treatment groups [2 deoxy glucose (4mM), Metformin (5mM), AICAR (2mM), 2 deoxy glucose (4mM) plus Metformin (5mM) and 2 deoxy glucose (4mM) plus AICAR (2mM)] with non treated control groups for 12 hrs. Each groups was quadruplicated. Microarray experiments and data analysis were done at Dept. of Systems Biology, MDACC (Houston, USA)
2012-12-31 | E-GEOD-16816 | biostudies-arrayexpress
Project description:Transcriptional profiles of S. cerevisiae strains with deletions of mth1, std1, or both were compared to that of a wild-type strain during growth on synthetic complete media with galactose as the carbon source, with the intent to understand each protein's contribution to the cells' response to glucose.
2009-09-03 | GSE17437 | GEO
Project description:Metformin is a type 2 diabetes medication which extends life span across species when given from young adulthood onwards; late life effects of metformin are not well understood. Here we used C. elegans to investigate the outcome of metformin treatment initiated late in life. We found that, contrary to young age administration, old age metformin treatment interferes with energy homeostasis and shortens life span by aggravating age-associated mitochondrial dysfunction. Nematode mutants defective in mitochondrial respiration, mitochondrial biogenesis and mitochondrial quality control were highly susceptible to metformin killing already at young age while insulin receptor deficient nematodes carrying healthier mitochondria were protected from late life metformin toxicity. In the mammalian cell culture model of replicative senescence metformin killing correlated with loss of mitochondrial membrane potential and strong reduction of systemic ATP levels. Reduced ATP levels and depletion of lipid stores consistent with energy deficit were observed also in nematodes following late life metformin treatment. At the molecular level young animals responded to metformin by inducing adaptive stress responses and longevity-assurance pathways while old nematodes demonstrated a protein expression signature consistent with lipid turnover and energy deficit. Ectopic ATP supplementation was sufficient to alleviate metformin toxicity in human skin fibroblasts highlighting the key contribution of energy deficit to the detrimental effect of metformin. Also, co-exposure with rapamycin, known to stabilize cellular ATP levels under conditions of mitochondrial failure, significantly reduced metformin-inflicted lethality in both cells and old animals. In summary we uncovered a novel negative synergism between metformin treatment and mitochondrial dysfunction which gains importance late in life and may limit therapeutic benefits of metformin for older patients; these side effects can partially be overcome by co-treatment with agents stabilizing cellular ATP levels such as rapamycin.
2020-09-21 | PXD011579 | Pride
Project description:In contrast to batch cultivation, chemostat cultivation allows the identification of carbon source responses without interference by carbon-catabolite repression, accumulation of toxic products, and differences in specific growth rate. This study focuses on the yeast Saccharomyces cerevisiae, grown in aerobic, carbon-limited chemostat cultures. Genome-wide transcript levels and in vivo fluxes were compared for growth on two sugars, glucose and maltose, and for two C2-compounds, ethanol and acetate. In contrast to previous reports on batch cultures, few genes (180 genes) responded to changes of the carbon source by a changed transcript level. Very few transcript levels were changed when glucose as the growth-limiting nutrient was compared with maltose (33 transcripts), or when acetate was compared with ethanol (16 transcripts). Although metabolic flux analysis using a stoichiometric model revealed major changes in the central carbon metabolism, only 117 genes exhibited a significantly different transcript level when sugars and C2-compounds were provided as the growthlimiting nutrient. Despite the extensive knowledge on carbon source regulation in yeast, many of the carbon source-responsive genes encoded proteins with unknown or incompletely characterized biological functions. In silico promoter analysis of carbon source-responsive genes confirmed the involvement of several known transcriptional regulators and suggested the involvement of additional regulators. Transcripts involved in the glyoxylate cycle and gluconeogenesis showed a good correlation with in vivo fluxes. This correlation was, however, not observed for other important pathways, including the pentose-phosphate pathway, tricarboxylic acid cycle, and, in particular, glycolysis. These results indicate that in vivo fluxes in the central carbon metabolism of S. cerevisiae grown in steadystate, carbon-limited chemostat cultures are controlled to a large extent via post-transcriptional mechanisms. Experiment Overall Design: Cultivation of microorganisms in chemostats offers numerous advantages for studying the structure and regulation of metabolic networks (11). In chemostat cultures, individual culture parameters can be changed, while keeping other relevant physical and chemical culture parameters (composition of synthetic medium, pH, temperature, aeration, etc.) constant. An especially important parameter in this respect is the specific growth rate, which, in a chemostat, is equal to the dilution rate, which can be accurately controlled. This allows the experimenter to investigate the effects of environmental changes or genetic interventions at a fixed specific growth rate, even if these changes result in different specific growth rates in batch cultures. In a chemostat, growth can be limited by a single, selected nutrient. The very low residual concentrations of this growth-limiting nutrient in chemostat cultures alleviate effects of catabolite repression and inactivation. Furthermore, these low residual substrate concentrations prevent substrate toxicity, which, for example, occurs when S. cerevisiae is grown on ethanol or acetate as the carbon source in batch cultures . Experiment Overall Design: The central goal of the present study is to assess to what extent carbon source-dependent regulation of fluxes through central carbon metabolism in S. cerevisiae is regulated at the level of transcription. To this end, we compare the transcriptome of carbon-limited, aerobic chemostat cultures grown on four different carbon sources: glucose, maltose, ethanol, and acetate. Data from the transcriptome analysis are compared with flux distribution profiles calculated with a stoichiometric metabolic network model. Questions that will be addressed are as follows: (i) does glucose-limited aerobic cultivation lead to a complete alleviation of glucose-catabolite repression; (ii) how (in)complete is our understanding of the genes involved in the transcriptional response of S. cerevisiae to four of the most common carbon sources for this yeast; and (iii) to what extent do transcriptome analyses with microarrays provide a reliable indication of flux distribution in metabolic networks?
2008-06-16 | E-GEOD-8895 | biostudies-arrayexpress
Project description:In response to limited nitrogen and abundant carbon sources, diploid Saccharomyces cerevisiae strains undergo a filamentous transition in cell growth as part of pseudohyphal differentiation. Use of the disaccharide maltose as the principal carbon source, in contrast to the preferred nutrient monosaccharide glucose, has been shown to induce a hyper-filamentous growth phenotype in a strain deficient for GPA2 which codes for a Gï¡ protein component that interacts with the glucose-sensing receptor Gpr1p to regulate filamentous growth. In this report, we compare the global transcript and proteomic profiles of wild-type and Gpa2p deficient diploid yeast strains grown on both rich and nitrogen starved maltose media. We find that deletion of GPA2 results in significantly different transcript and protein profiles when switching from rich to nitrogen starvation media. The results are discussed with a focus on the genes associated with carbon utilization, or regulation thereof, and a model for the contribution of carbon sensing/metabolism-based signal transduction to pseudohyphal differentiation is proposed. Experiment Overall Design: For transcriptome profiling, there were 12 Affymetrix Yeast S98 microarrays total. There were four conditions: wildtype MLY61 and gpa2 deletion mutant MLY132 grown in YPM media or transferred to low nitrogen media SLAM. Each condition was done in triplicate, starting with triplicate yeast cultures. Four conditions done in triplicates resulted in 12 samples that went onto 12 microarrays.
2008-06-15 | E-GEOD-7820 | biostudies-arrayexpress