Estimating networks from RNA interference and microarray data
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Mark Fellmann
PROVIDER: E-GEOD-7033 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:End stage heart failure due to ischemic cardiomyopathy (ICM) and dilated cardiomyopathy (DCM) have similar characteristics, enlargement of the ventricles, relatively thin-walled ventricle, which leads to a limited contraction force and blood loading. Nevertheless, the response for present therapeutics is very variable and the prognosis is still very bad for ICM and DCM in general. Thus, the ability to differentiate the etiologies of heart failure based structural and physiological changes of the heart would be a step forward to enhance the specificity and the success of given therapy.
2007-10-31 | E-CVDE-1 | biostudies-arrayexpress
Project description:Comparison between Estrogen receptor positive and Estrogen receptor negative breast cancer samples Keywords: breast cancer type comparison 152 unique breast cancer tissue sample are included in the analysis. The total mRNA has been labeled with Cy5 and then hybridized on a two color arrays against the stratagen Human common reference that was previously labelled with Cy3.
2008-09-17 | E-GEOD-10510 | biostudies-arrayexpress
Project description:The intention of this study is to analyse the effect of antibiotics on the gene expression of Escherichia coli. Shaking-flask cultivations of Escherichia coli K12GFP-UTL2 were carried out with a medium containing nalidixic acid. Cultures with antibiotic-free medium, which were run in an identical way, served as reference. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Keywords: Influence of toxins on gene expression in E. coli A timeserial experiment of the influence of nalidixic acid on the gene expression in Escherichia coli was performed. Effects of the growth curve were eliminated by bionformatic methods.
2010-05-25 | E-GEOD-8674 | biostudies-arrayexpress
Project description:Glucose uptake in Escherichia coli had been studied extensively, but the lack of basic information of glucose uptake systems in C. acetobutylicum has limited the understanding of glucose assimilation in this strain. There is a main glucose transporter which is very efficient for glucose uptake and the maltose, mannose and galactose transport systems are also able to transport glucose into cytoplasm of E.coli. Therefore, it is very interesting to investigate whether a similar glucose transport mechanism exists in C. acetobutylicum.
2022-12-28 | E-MTAB-12054 | biostudies-arrayexpress
Project description:Myelodysplastic syndromes (MDS) are a group of clonal disorders of hematopoietic stem cells. Mesenchymal stem cells (MSC) are the progenitors of the Bone Marrow (BM) stroma and have been involved in the physiopathology of MDS. The presence of cytogenetic aberrations on MSC from MDS patients is controversial. The aim of the study is to characterize BM derived MSC from patients with MDS using: kinetic studies, immunophenotyping, fluorescent in situ hybridisation (FISH) analysis and genetic changes by array based comparative genomic hybridization (array-CGH). 32 cases of untreated MDS were included in the study. MSC from MDS achieved confluence at a slower rate than donor-MSC, and the antigenic expression of CD105 and CD104 was also lower. Array-CGH studies showed DNA genomic changes that were proved not to be somatic, and gains were more frequent than looses. The results of array-CGH were confirmed by FISH. When an unsupervised hierarchical cluster analysis was performed two clusters were identified: one of them included the 5q- syndrome patients, while the other incorporated the rest of the MDS patients. Our results shows, for the first time, that MSC from MDS display genomic aberrations, assessed by array-CGH and FISH, some of them specially linked to particular MDS subtypes. Keywords: Genomic comparison between mesenchymal cells 32 BM cells from âde novoâ MDS, corresponding to 29 patients, were included in the study. Male/female ratio was 14/15 and median age was 70 years (range 34-89). MDS diagnosis was established by peripheral blood counts and morphology, BM morphology and cytogenetic analyses and classified according to the WHO proposals. 12 Patientsâ characteristics are summarized in table 1. Three patients were included twice in the study: at the diagnosis of one RA (case 2) and two Unclassifiable MDS (cases 29,30), and at the progression into RAEB-2 (cases 16, 20 and 18). None of them had received treatment during this period of time, other than supportive therapy. Normal BM samples were obtained from 15 healthy donors, 8 males and 7 females, with a median age of 57 (range 37-88). Written informed consent was obtained from all patients and donors according to ethical guidelines of our institution. Genomic-wide analysis of DNA copy number changes of MSC from 13 cases was performed using array-CGH. Slides containing 3032 BACs were produced in âCentro de Investigación del Cáncerâ (Salamanca, Spain). The particular BAC and P-1 derived artificial chromosome set used to produce this array is distributed to academic institutions by the Welcome Trust Sanger Institute (Cambridge, United Kingdom) and contains targets spaced at ï» 1 Mb density over full genome, a set of subtelomeric sequences for each chromosome arm, and a few hundred probes selected for their involvement in oncogenesis. The clone content is available in the âCytoviewâ windows of the Sanger Institute mapping database site, Ensembl (http://www.ensembl.org/). According to this database, clones were ordered along the chromosomes. These clones were isolated from their bacterial cultures with the relevant antibiotics and the DNA was extracted with standard protocol Welcome Trust Sanger Institute (Cambridge, UK). 10 ng of DNA (BAC/PAC) was used as a template for three DOP-PC. 22;23 These products were ethanol precipitated and dissolved in distilled water. A minimum of three replicates per clone were printed by Microgrid II (Biorobotics) on each slide (Ultragaps Coated Slides, Corning) using the aqueous dimethylsulfoxide buffer as spotting solution. Briefly, for labelling reactions, 1 μg of nonamplified genomic DNA, test and reference were digested separately with DpnII restriction enzyme (New England Biolabs, Beverly, MA). For microarray hybridization, the digested DNAs were separately labelled using random primers (Bioprimer labelling kit, Invitrogen) and cyanine dye-3-dCTP and cyanine dye-5-dCTP fluorescent dye to paired hybridisation samples (Amersham Biosciences). The incorporated of the label nucleotide was quantified using the Nanodrop spectrophotometer. Labelled test and reference DNAs were mixed equitably, co-precipitated in presence of Cot-1 human DNA (Roche, Indianapolis, IN) with ethanol, washed, and resuspended in hybridization solution (50% Formamide, 10% Dextran sulfate, 2X standard saline citrate, 10 mM Tris pH 7.6, 2.7% sodium dodecyl sulfate and 10 μg/ μl of yeast tRNA). DNA mixtures were hybridized to the arrays in the TECAN HS4800 Pro according to the manufacturerâs recommended protocol. Images and signal intensities were acquired using GenePix4000B (Axon Instruments, Burlingame, CA) dual laser scanner in combination with GenePixPro4.0 (Axon Instruments) imaging software. Image and Data analysis. Spot intensities measured by the GenePix Pro 4.1 software (Axon Instruments, Wetsbur BV, Leuden, The Netherland). Pixel intensities for each feature were integrated and median values were determined, and the local background was calculated. For each spot the intensities were corrected by subtracting the local background for both wavelengths, and only spots with signal intensities al least threefold above background signal intensities were included in the analysis. The median of the ratios of all spots was calculated and used to normalize all data points. From each feature, the log2 value of the average of the normalization ratios of the spots was calculated and used to display the data. In addition, fluorescence ratios were normalized for each microarray using the print-tip loess method and the background subtraction with the Diagnosis and Normalization Arrays Data tool. 24 The cut-off level was determined for each individual experiment after avering the ratios from the two color-swith hybridizations and subsequent for normalization, and calculate the mean and Standard derivations to define the cut-off level as means plus/minus two times the standard derivations. The clones that showed possible changes were submitted to the Database of Genomics Variants (http://projects.tcag.ca/variation/) and chromosomal Imbalances and Phenotype in Humans using Ensembl Resources (DECIPCHER: http: www sanger. ac.uk /PostGenomics/decipher/. Clustering Unsupervised clustering We converted the relative ratio value for each BAC clones in each sample to score of 1 (gain/amplified), 0 (no change), or -1 (loss) based on the 2 SD standards described above and analyzed with Cluster and TreeView) 25 (Cluster and TreeView software) based on the average linkage method with the centered correlation metric was used (or Pearson Uncentered). Supervised Sam analysis was used http://www-stat.stanford.edu/ tibs/SAM) 26 to identify BACs that segregate subgroups on MSC. BACs with an SD of zero across the data set before analysis were removed.
2010-05-25 | E-GEOD-10822 | biostudies-arrayexpress
Project description:C. acetobutylicum pflB::int(1335) and its parental wild-type strain were cultivated in a batch culture to identify, via DNA microarray analyses, changes in the gene expression.
2014-04-01 | E-MTAB-2059 | biostudies-arrayexpress
Project description:DNA microarray analysis of C.acetobutylicum mutants with defects in several fermentative branch points
2014-03-16 | E-MTAB-2058 | biostudies-arrayexpress
Project description:Oxidative stress is harmful for organism and occurs when the cells exposed to superoxid, hydrogen peroxide and alkylhydroperoxides. In microorganism, the glutathione- and thioredoxin-dependent reduction systems are universal and play an important role in response to defending oxidative stress. The _-glutamylcysteine synthetase (_-GCS) is an essential enzyme to biosynthesize the tripeptide glutathione (GSH) in organism. Similarly, thioredoxin reductase is an important enzyme in thioredoxin-dependent reduction system. In Clostridium acetobutylicum, the _-glutamylcysteine synthetase (encoded by CAC1539, gcs) and thioredoxin reductase (encoded by CAC1548, trxB) were inactivated using ClosTron technology. The gcs mutant grew insufficiently and consumed less glucose in the phosphate-limited continuous culture and exhibited more sensitive to oxidative stress. The trxB mutant just exhibited lower growth rate and less glucose uptake in the solventogenic phase, compared to wild type. The DNA microarrays were performed to investigate the transcripome difference between wild type and the mutants. In gcs mutant, the genes related to chemotaxis and flagella biosynthesis proteins were induced significantly and in the trxB mutant, the sporulation genes were induced largely. Based on the phenotypes and transcriptome comparison results, the relationship between GSH- and Trx-dependent induction systems was discussed in Clostridium acetobutylicum.
2015-04-13 | E-MTAB-2747 | biostudies-arrayexpress
Project description:The batch fermentation of Clostridium acetobutylicum is characterized by an acetogenic growth phase during exponential growth when mainly acetate and butyrate are fermentation products. Then, at the end of exponential growth and during stationary phase, the organism switches to solventogenic growth and large amounts of acetone, ethanol and butanol are produced. These growth phases can be studied independent from each other in a phosphate-limited continuous culture. In transcription analysis of continuous cultures using DNA microarrays it became evident that, among others, operons involved in sulfur assimilation are strongly up-regulated during solventogenesis. Using the ClosTron technique we constructed two knock-out mutants in the genes CAC0105 and CAC0930 annotated as involved in sulfate reduction and cysteine biosynthesis. Complementation experiments were carried out with sulfite and cysteine to prove the predicted function. The fermentation experiments of wild type and mutants using phosphate-limited and sulfur-limited continuous culture demonstrated that less sulfur source was consumed in solventogenic phase and the efficiency of cysteine uptake became lower. DNA microarrays were performed to study the difference of transcriptional expression when the wild type was challenged with insufficient sulfur source and the mccB (CAC0930) mutant was inactivated in the continuous culture. The result provided insights into understanding the sulfur metabolism regulatory.
2015-04-15 | E-MTAB-2745 | biostudies-arrayexpress