Project description:Various bis-benzimidazole derivatives have been reported to possess activity against Gram-positive pathogens. No mechanism of action has been elucidated to fully account for the antibacterial activity of this class of compounds. A group of symmetric bis-benzimidazoles (BBZ) designed as anticancer agents have previously been shown to possess moderate antiproliferative activity. We sought to assess the antibacterial activity and mechanism of action of BBZ compounds against Staphylococcus aureus. Antibacterial activities were assessed by determination of minimal inhibitory concentrations (MICs), time-kill curves, and scanning electron microscopy. Transcriptional responses to BBZ treatment were determined using whole genome microarrays. Activities against bacterial type II topoisomerases were investigated using in vitro supercoiling, decatenation, DNA binding, and DNA cleavage inhibition assays. MICs for EMRSA-16 were between 0.03 and 0.5 μg/mL. The compounds showed concentration-dependent bactericidal activity and induced cell swelling and lysis. Transcriptional responses to BBZ were consistent with topoisomerase inhibition and DNA damage. A subset of BBZ compounds inhibited S. aureus DNA gyrase supercoiling activity with IC50 values in the range of 5−10 μM. This inhibition was subsequently shown to operate through both inhibition of binding of DNA gyrase to DNA and accumulation of single-stranded DNA breaks. We conclude that BBZ compounds are potent antistaphylococcal agents and operate at least in part through DNA gyrase inhibition, leading to the accumulation of single-stranded DNA breaks, and by preventing the binding of gyrase to DNA. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-106]
Project description:Identification of novel pathways in the development of atherosclerosis. Here, we are looking at changes in gene expression that occur in the aorta with the development of atherosclerosis Analysis used RNA from thoracic aortas from chow fed ApoE knockout mice as control samples for comparison to the experimental samples from 8 week and 16 week ApoE knockout mice fed a western-type diet
Project description:Elevated levels of adsorbable organic bromine compounds (AOBr) have been detected in German lakes, and cyanobacteria like Microcystis, which are known for the synthesis of microcystins, are one of the main producers of natural organobromines. However, very little is known about how environmental realistic concentrations of organobromines impact invertebrates. Here, the nematode C. elegans was exposed to AOBr-containing surface water samples and to a Microcystis aeruginosa enriched batch culture (MC-BA) and compared to single organobromines and microcystin-LR exposures. Stimulatory effects were observed in certain life trait variables, which were particularly pronounced in nematodes exposed to MC-BA. A whole genome DNA-microarray revealed that MC-BA led to the differential expression of more than 2000 genes, many of which are known to be involved in metabolic, neurologic, and morphologic processes. Moreover, the up-regulation of cyp- and the down-regulation of abu-genes suggested the presence of chronic stress. However, the nematodes were not marked by negative phenotypic responses. The observed difference in MC-BA and microcystin-LR (which impacted lifespan, growth and reproduction) exposed nematodes was hypothesized to be likely due to other compounds within the batch culture. Most likely the exposure to low concentrations of organobromines appears to buffer the effects of toxic substances, like microcystin-LR. Nematodes were exposed to filtrated samples of Lake Stößensee Berlin (August and October) and compared to the control-group (exposure to water). Furthermore, nematodes were exposed to filtrated M. aeruinosa batch culture samples and compared to another control-group (exposure to Z-Medium). Three samples (biological replicates) were prepared for each group.
Project description:This SuperSeries is composed of the following subset Series: GSE16733: Analysis of Gene Expression in Tissues of Two Turmeric Varieties at Different Developmental Stages GSE16734: Analysis of Gene Expression in Ginger Tissues at Different Developmental Stages Refer to individual Series
Project description:To identify novel miRNA and NAT-siRNAs that are associated with salt and cold stresses in Arabidopsis, we generated small RNA sequences from Arabidopsis plants under salt and cold stress treatments. Sequencing of small RNAs in Arabidopsis under salt, and cold stress conditions.
Project description:In the current report, we report that ThbZIP1 is a direct target gene of the ThABF1 transcription factor. There are three ABRE motifs in the promoter of ThbZIP1, Yeast one-hybrid (Y1H) assays showed that a ABF protein, ThABF1, specifically binds to the ABRE motifs. The interaction between ThABF1 and the promoter of ThbZIP1 was further confirmed by transient expression assays in tobacco leaves. Chromatin Immunoprecipitation (ChIP) results suggested that binding of ThABF1 to ABRE motifs in the promoter of ThbZIP1 occurs in vivo in Tamarix hispida to regulate the expression of ThbZIP1. Moreover, ThABF1 and ThbZIP1 share similar expression patterns in response to salt, drought, ABA, methyl viologen (MV) and cold stress. Microarray analyses results showed there were 1,662 and 1,609 genes that were significantly upregulated or downregulated, respectively, under ABA stress conditions. ThbZIP1 regulated the genes via binding to the C-, G- or A-box motifs in their promoter sequences. Based on these data, the results suggested a regulatory network model mediated by ThbZIP1, under abiotic stress conditions, ThABF1 regulates the expression of ThbZIP1, and the activated ThbZIP1 binds to bZIP recognition sequences or other motifs to regulate the expression of genes containing these motifs in their promoters. Differentially expression genes of ThbZIP1-overexpression plants and wild type of Columbia Arabidopsis thaliana were measured under ABA stressed and normal condition for 3 hours, respectively. Two independent experiments were performed at each treatment using different plants for each experiment.
Project description:This SuperSeries is composed of the following subset Series: GSE39711: RpoHI and RpoHII regulons in Rhodobacter sphaeroides 2.4.1 from chromatin immuno-precipitation GSE39712: RpoHI and RpoHII regulons in Rhodobacter sphaeroides 2.4.1 from gene expression profiling Refer to individual Series
Project description:In this study, analysis of miRNA expression changes in osteoclast differentiation from human primary monocytes revealed the rapid upregulation of two miRNA clusters, miR-212/132 and miR-99b/let-7e/125a. We demonstrate that they negatively target monocyte-specific and immunomodulatory genes like TNFAIP3, IGF1R and IL15. Depletion of these miRNAs inhibits osteoclast differentiation and upregulates their targets. These miRNAs are also upregulated in other inflammatory monocytic differentiation processes. Most importantly, we demonstrate for the first time the direct involvement of Nuclear Factor kappa B (NF-κB) in the regulation of these miRNAs, as well as with their targets, whereby NF-κB p65 binds the promoters of these two miRNA clusters and NF-κB inhibition or depletion results in impaired upregulation of their expression. Human primary CD14+ cells isolated from three different donors, and differentiated into osteoclast with MCSF and RANKL for 21 days. miRNA expression analyzed in paired samples at day 0, 2 and 21
Project description:Plant hormones interact with each other and regulate gene expression to control plant growth and development. To understand the complex network, accumulation of comprehensive and integrative data of gene expression and hormone concentration is important. Using microarray, global gene expression profile was analyzed to compare with plant hormone concentration in 14 parts of rice at reproductive stage. The microarray data are used to construct public rice hormonome-transcriptome database UniVIO (http://univio.psc.riken.jp/). We analyzed flower, panicle branch,internode I, node I and II, and some leaves of rice plant at the heading satage. Total 35 samples were analyzed in this experiment.
Project description:By using ChIP-seq, we found that loss of BRM activity in developing seedlings leads to ectopic and increased H3K27me3 deposition at several hundred genes, indicating the critical role of BRM in preventing the inappropriate deposition of this histone mark. Removal of CLF in brm mutant could partcially suppress the increased H3K27me3. Examination of H3K27me3 in 14-day-old wt, brm, clf, and brm clf seedlings. Two biological replicates for each one.