E.coli DH5alpha cells: reuterin-treated vs. untreated control cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Escherichia coli DH5[alpha]
SUBMITTER: Robert Britton
PROVIDER: E-GEOD-19760 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Photorhabdus luminescens lives in a mutualistic association with entomopathogenic nematodes and is pathogenic for insects. Variants of Photorhabdus frequently arise. VAR* is a colonial and phenotypic variant displaying delayed pathogenicity in the insect, Spodoptera littoralis. In this study, we evaluated the role of transcriptomic modulation in determining the phenotypic variation and delayed pathogenicity of VAR* with respect to the corresponding wild-type form, TT01alpha. A P. luminescens microarray was used to determine changes in transcript profiles in the exponential and stationary phase growth phase of VAR* and TT01alpha grown in LB broth. Direct transcriptomic comparisons were carried out between VAR* and TT01alpha grown in LB broth. RNA were extracted from bacterial cells in the exponential growth phase (6-hour-old culture, 5 x 107 cfu/ml) and stationary phase (45-hour-old culture, 5 x 108 cfu/ml). Each microarray comparison (TT01alpha versus VAR* growth in exponential growth or stationary phase) included six slides, with three dye-swapping replicates. Each microarray comparison is done twice with two independant biological extractions (repbiol1 or 2).
2010-10-13 | E-GEOD-24627 | biostudies-arrayexpress
Project description:Insect cuticle plays essential roles in multiple physiological functions. During molting and metamorphosis, tremendous changes occur in silkworm cuticles. Silkworm is a model of Lepidoptera insects; however, little is known about the stage expression profiles of genes in cuticles of silkworm. In the present study, we selected 16 developmental stages, ranging from day 1 of the first instar larvae to day 8 of pupae, to perform microarray-based expression profiles. The data told us that various functions and physiological pathways were activated in the cuticle. Moreover, the expression profiles of cuticular protein genes, as the important components of cuticle, were investigated. The current study provides important insights for the functional study of insect cuticle and the regulation of insect cuticular protein genes. Transcription profiling experiments, 16 developmental stages (samples) were analyzed. Dual-channel experiments, with test samples labeled by Cy5 and common reference samples labeled by Cy3. Common reference sample was used for data normalization. One biological replicate. No dye-swaps.
2009-11-04 | E-GEOD-18878 | biostudies-arrayexpress
Project description:Phagocytosis and killing of the opportunistic pathogen Pseudomonas aeruginosa by polymorphonuclear neutrophils (PMNs) is the major antipseudomonal host defense of vertebrates. By screening a transposon library of the clinical P. aeruginosa isolate TBCF10839 that can grow and replicate in PMNs, a mutant was identified that was most strongly sensitized to killing by PMNs. The inactivated gene PA1572 termed nadK1 was found to encode an ATP:NAD kinase. The transcriptomes of the TBCF10839 wild type and nadK1 mutant were investigated in the presence of PMNs or H2O2. Exposure to H2O2 led to diametrical mRNA expression profiles. H2O2-degrading enzymes were upregulated by wild type, but not by nadK1 mutant. This data demonstrates that NadK1 is crucial for the response of P. aeruginosa to reactive oxygen species. The transcriptomes of Pseudomonas aeruginosa TBCF10839 wild type and nadK1 mutant were comparatively investigated in the presence of polymorphonuclear neutrophils or H2O2 in order to investigate the role of NadK1 in oxidative stress response. These samples represent test samples. The expression profile of Pseudomonas aeruginosa strain TBCF10839 wild type cells, isolated from a Cystic Fibrosis patient, was investigated under standard growth conditions in batch culture in Luria broth (LB) with no treatment. These samples represent reference samples. All samples were analyzed in duplicate.
2010-05-27 | E-GEOD-21704 | biostudies-arrayexpress
Project description:Transcriptional characteristics of genes in the fat body of domestic silkworms after 24 h exposure to phoxim through whole-genome oligonucleotide microarray. Transcriptional profiling of fat body in the domestic silkworms comparing control untreated fat body with phoxim-treated fat body Transcription profiling experiments, phoxim-treated fat body (samples) were analyzed. Dual-channel experiments, with test samples labeled by Cy5 and control samples labeled by Cy3. Three Biological replicate. No dye-swaps.
2016-07-03 | E-GEOD-60877 | biostudies-arrayexpress
Project description:CRZ is a C2H2 zinc finger transcription factor activated by calcineurin, a protein phosphatase activated by calcium-calmodulin, in different stress conditions related with calcium cell accumulation. CRZ binds to a specific element on the promoter region of genes called CDRE (calcineurin-dependent response element) shown to be sufficient for calcium- and calcineurin-dependent gene expression. In order to investigate which pathways are involved under calcium stress conditions, we determined the transcriptional profile of A. fumigatus delta crzA mutant strain upon a time course 200 mM calcium chloride treatment. Conidia from the mutant and wild type strains were incubated at 37°C in complete medium for 16 hours and were challenged with 200 mM calcium chloride for 10 and 30 minutes. At each time point, the mycelia were harvested by centrifugation and used for competitive microarray hybridizations. We were able to observe a decreased mRNA expression of genes encoding inorganic ion transport proteins and lipid transport. In contrast, increased mRNA expression was observed for several genes involved in transcription, energy production and conversion, cell cycle control, cell division, chromosome partitioning, amino acid, lipid and carbohydrate transport and metabolism, nucleotide transport, cell wall and membrane biogenesis, posttranslation modifications, protein turnover, chaperones, inorganic ion transport, signal transduction mechanisms, intracellular trafficking, secretion and vesicular transport. Keywords: gene expression array-based (log2 ratio) For the time course microarray experiments, 5.0 x 108 conidia of A. fumigatus wild type [CEA17 delta akuB(KU80)] and delta crzA strains were inoculated in 300 ml of pre-warmed liquid cultures (YG) in 500-mL erlenmeyer flasks and allowed to grow for 16 hours in a reciprocal shaker (250 rpm) at 37°C. After this time, the cultures were added by calcium chloride (200 mM) and incubated for 10 and 30 more minutes before mycelia recovery and RNA extraction. Hybridization experiments were competitive using probes derived from calcium chloride shock cultures using the wild type strain exposed to calcium (10 or 30 minutes) as the reference RNA for every hybridizantion. Normalized signal intensities were used to generate relative hybridization ratios (query/reference). Following normalization, the values for each gene's in-slide replicates were averaged (median variance <0.01), and corresponding flip-dye replicates were averaged to compensate for dye-specific effects. These final, processed data are linked below as supplementary files.
2010-06-20 | E-GEOD-15432 | biostudies-arrayexpress
Project description:While significant advances have been made in EHEC pathogenesis, we still do not fully understand the impact of environmental stress on EHEC virulence. During the course of infection, EHEC must evade or overcome several biological barriers, the first of which is the gastric acidity encountered during passage through the stomach. EHEC is remarkable in its ability to tolerate this acidity. There are four different acid resistance systems that provide E. coli O157:H7 protection against exposure to low pH (2-2.5). Interestingly, EHEC uses these acid resistance systems differentially for survival in foods versus the bovine intestinal tract. The glutamate-dependent acid-resistance system is thought to offer the best protection below pH 3. Since the infectious dose of EHEC is so low (50-100 organisms), acid resistance becomes an important virulence trait. Studies of EHEC response to acid stress have focused primarily on levels of acid tolerance and the molecular basis of tolerance. However, the impact of acid stress on EHEC virulence is less well understood. In the related pathogen, EPEC, the plasmid-encoded regulator, Per, that regulates expression of many EPEC virulence factors, is regulated negatively at pH 5.5 and positively at pH 8.0, suggesting that virulence gene expression is repressed during mild acid stress and enhanced in alkaline pH typical of the small intestine. Expression of EPEC type III secreted factors involved in A/E lesion formation has been shown to be influenced by factors including culture media, iron and calcium levels. Protein secretion was inhibited at pH 6 and 8. In a third study, a gadE (encoding acid resistance regulator) mutation resulted in increased adhesion of E.coli O157:H7 to colonic epithelial cells, suggesting negative regulation of one or more adhesins. Other studies have reported that shiga toxin production is sensitive to culture conditions including pH. However, there are no studies of EHEC virulence changes after more severe acid stress nor studies linking stressed EHEC virulence phenotype with transcriptional changes. The goal of this study was to determine how acid stress affects EHEC virulence properties and through microarray analysis, define the genetic basis for these changes. Understanding how acid stress modulates the virulence potential of this pathogen is essential for delineating the pathogenesis of disease caused by EHEC infection and may offer novel approaches to prevent and treat EHEC infections. Bacteria were grown in LB broth overnight, then subcultured into DMEM and grown at 37C, 5%Co2. Bacteria were then subjected to one of three acid stress protocols: 1) UA30: growth in DMEM pH 7.4 followed by growth in DMEM pH 3.0 for 30 minutes; 2) AA30: growth in DMEM pH 5.0 (adaptation) followed by growth in DMEM pH 3.0; 3) UA15: growth in DMEM pH 7.4 followed by growth in DMEM pH 3.0 for 15 minutes. DMEM was supplemented with 25 mM MES (pH 5.0) and in the case of the control (unadapted, unshocked) 25 mM MOPS (pH 7.4) and the adaptation step was again carried out at 37C and 5% CO2. Acid shocking was done at pH 3.0 (unbuffered) at room temperature for all treatments
2010-05-16 | E-GEOD-14069 | biostudies-arrayexpress
Project description:Heme, an iron-containing prosthetic group found in many proteins, carries out diverse biological functions such as electron transfer, oxygen storage and enzymatic reactions. Hemin, the oxidised form of heme, is used to treat porphyria and also to activate heme-oxygenase (HO) which catalyses the rate-limiting step in heme degradation. Our group has previously demonstrated that hemin displays antitumor activity in breast cancer (BC). The aim of this work has been to study the effect of hemin on protein expression modifications in a BC cell line to gain insight into the molecular mechanisms of hemin antitumor activity. For this purpose, we carried out proteome analysis by Mass Spectrometry (MS) which showed that 1309 proteins were significantly increased in hemin-treated cells, including HO-1 and the proteases that regulate HO-1 function, and 921 proteins were significantly decreased. Furthermore, the MS-data analysis showed that hemin regulates the expression of heme- and iron- related proteins, adhesion and cytoskeletal proteins, cancer signal transduction proteins and enzymes involved in lipid metabolism. By biochemical and cellular studies, we further corroborated the most relevant in-silico results. Altogether, these results show the multiple physiological effects that hemin treatment displays in BC and demonstrate its potential as anticancer agent.
2023-07-20 | PXD036701 | Pride
Project description:Comparison of ds-cDNA, Indirect and Direct Random Labeling Methods for gene expression analysis on the NimbleGen platform. Expression profiles from artemisinic acid-producing S. cerevisiae strain EPY330 and non-producing strain EPY338 are compared for each labeling method tested. The labeling methods and their comparison are described in detail in Ouellet et al., BMC Biotech 2009. Strains were described in detail previously in Ro et al. BMC Biotechnol 2008, 8(1):83 [PMID: 18983675] RNA pools from strains EPY330 (sample A) and EPY338 (sample B) were reverse-transcribed and labeled in triplicate with the ds-cDNA, the Indirect and the new Direct Random method and hybridized in parallel on NimbleGen 4-plex arrays.
2010-05-19 | E-GEOD-15816 | biostudies-arrayexpress
Project description:The effect of respiration (aerobic cultivation in the presence of heme and vitamin K2) was compared with unsupplemented aerobic cultivation with Lactobacillus plantarum. Two-condition experiment, aerobic vs respiring cells. Biological replicates: 3 aerobic cultures, 3 respiring cultures, independently grown and harvested. One replicate per array. Respiring cultures are called reactor 1-3; Aerobic cultures are called reactor 4-6 In the subsequent analysis data from reactor 4 were not used. There was likely a mistake made during quenching. This was concluded as new labeling/hybridisation gave same (bad) results (128a); slide 128b was dye-swap.
2010-05-16 | E-GEOD-18432 | biostudies-arrayexpress
Project description:Objectives: The aim of the study was to characterize (-)-α-Pinene, which is one of the chemical constituents of Alpinia katsumadai seed essential oil responsible for its resistance modulatory activity in Campylobacter jejuni. Methods: Broth microdilution method was used to evaluate the antimicrobial and resistance modulatory potential of (-)-α-Pinene and ethidium bromide accumulation assay to determine its efflux-inhibitory activity in subinhibitory concentration. The target efflux system was identified using knock-out mutants in several efflux related genes. Furthermore, the influence of subinhibitory concentration of (-)-α-Pinene on C. jejuni NCTC 11168 was investigated using microarray technology in order to elucidate the adaptive mechanism of bacteria to treatment with this phytochemical. Knock-out mutants of key adaptation genes were constructed and their role in adaptation to several stress factors, including (-)-α-Pinene, different osmolites and pH, was investigated using Biolog phenotypical microarrays and CFU counts. Results: (-)-α-Pinene was confirmed as highly efficient Campylobacter jejuni resistance modulator, due to its efflux inhibitory activity, which was significantly higher compared to reference inhibitors CCCP and reserpine. The CmeABC along with newly characterized CmeI (Cj1687) was confirmed as its main target efflux system. The transcriptional analysis indicated that the heat shock regulators HspR and HrcA are the main transcription regulators involved in adaptation to (-)-α-Pinene treatment. Conclusions: (-)-α-Pinene is a novel CmeABC and CmeI efflux inhibitor, which evokes the heat shock response in Campylobacter jejuni. Influence of (-)-α-Pinene on gene expression in C. jejuni NCTC 11168 was determined by expressional analysis and qRT-PCR. Exponential phase culture was adjusted to OD600=0.2 in MHB using spectrophotometer (Smart Spec, Bio-Rad, Hercules, CA, USA). Five ml of culture was treated with 62.5 mg/L of (-)-alpha-pinene dissolved in DMSO. Only DMSO (0.048 %) was added to untreated samples. Cultures were treated for 2 h, incubated microaerobically shaking (160 rpm) at 42°C. Experiments were carried out in 4 biological replicates. RNA Protect Bacteria reagent (Qiagen, Maryland, USA) was added to the culture and total RNA was isolated using RNeasy mini kit (Qiagen) and treated with Ambion® Turbo DNA-freeTM kit (Invitrogen, USA). Microarrays with 4751 probes targeting 1756 genes specific for Campylobacter jejuni subsp. jejuni NCTC 11168 (Mycroarray, Biodiscovery-LLC, MI, USA) were used for gene expression analysis. The cDNA was synthesized with random hexamers, SuperScriptTM III Reverse Transcriptase and amynoallyl dUTP (all supplied by Invitrogen, USA) and labeled with monofunctional NHS-ester dye Amersham C3 or Cy5 (GE Healthcare, Buckinghamshire, UK). Concentration of cDNA and labeling efficiency was determined spectrophotometrically with NanoDrop 1000. Four biological replicates were hybridized to four microarrays according to manufacturerâs protocol, incubated for 24 hours at 42â°C and scanned at 532-nm (Cy3) and 635-nm (Cy5) wavelengths using GenePix 4100A (Molecular Devices, Sunnyvale, CA) following the manufacturer's protocol. Fluorescence intensities of each spot were extracted using GenePix Pro 7.0 (Molecular Devices).
2015-11-19 | E-GEOD-59879 | biostudies-arrayexpress