MgrR is a newly characterized Hfq dependent small RNA RNA. The expression of MgrR is regulated by Two component system, PhoPQ regulon, which senses low Mg2+ in environment. It has been reported that Hfq-binding sRNAs base pair with target RNAs, frequently leading to rapid degradation of target messages or, less frequently, to stabilization, both of which can be assayed by using microarrays. In order to search for the target genes of MgrR, we therefore examined the consequences of MgrR expression on mRNA abundance under two conditions. In condition 1, the chromosomal copy of mgrR was deleted and MgrR was expressed for 15 from an induced plac-mgrR plasmid and compared to cells carrying a vector induced for the same period. In condition 2, the expression of mRNAs was compared in wild-type cells (mgrR+) and the mgrR deletion strain, both grown in LB; because MgrR levels are fairly high under our normal growth conditions, this allowed analysis of both the direct and indirect (long-term) effects of MgrR.
A PhoQ/P-regulated small RNA regulates sensitivity of Escherichia coli to antimicrobial peptides.
No sample metadata fields
View SamplesTranscription termination factor Rho is essential in enterobacteria. We inhibited Rho activity with bicyclomycin and used microarray experiments to assess Rho function on a genome-wide scale. Rho is a global regulator of gene expression that matches E. coli transcription to translational needs. Remarkably, genes that are most repressed by Rho are prophages and other horizontally-acquired portions of the genome. Elimination of these foreign DNA elements increases resistance to bicyclomycin. Although rho remains essential, such reduced-genome bacteria no longer require Rho cofactors NusA and NusG. Thus, Rho termination, supported by NusA and NusG, is required to suppress the toxic activity of foreign DNA.
Termination factor Rho and its cofactors NusA and NusG silence foreign DNA in E. coli.
Compound
View SamplesTo determine whether the polyamide-Chl conjugate 1R-Chl would cause similar changes in global gene expression in K562 cells, affymetrix gene chip analysis was performed using 1R-Chl. Through class comparison analysis, 1R-Chl affected the levels of transcription and genes of interest were determined.
Small molecules targeting histone H4 as potential therapeutics for chronic myelogenous leukemia.
Sex, Age, Disease
View SamplesLymphoblast cells from a patient with Freidriech's Ataxia were incubated with pyrrole-imidazole polyamides targeted to the GAA triplet repeat in the intron 1. The polyamides were shown in cell culture to increase levels of endogenous frataxin mRNA. A normal sibling derived lymphoblast cell line was used as a control.
DNA sequence-specific polyamides alleviate transcription inhibition associated with long GAA.TTC repeats in Friedreich's ataxia.
No sample metadata fields
View SamplesBackground: Cancer stem cells are presumed to have virtually unlimited proliferative and self-renewal abilities and to be highly resistant to chemotherapy, a feature that is associated with overexpression of ATP-binding cassette transporters. We investigated whether prolonged continuous selection of cells for drug resistance enriches cultures for cancer stem-like cells.
Prolonged drug selection of breast cancer cells and enrichment of cancer stem cell characteristics.
Cell line, Treatment
View SamplesBackground: Friedreich ataxia, an autosomal recessive neurodegenerative and cardiac disease, is caused by abnormally low levels of frataxin, an essential mitochondrial protein. All Friedreich ataxia patients carry a GAA/TTC repeat expansion in the first intron of the frataxin gene, either in the homozygous state or in compound heterozygosity with other loss-of-function mutations. The GAA expansion inhibits frataxin expression through a heterochromatin-mediated repression mechanism. Histone modifications that are characteristic of silenced genes in heterochromatic regions occur at expanded alleles in cells from Friedreich ataxia patients, including increased trimethylation of histone H3 at lysine 9 and hypoacetylation of histones H3 and H4.
HDAC inhibitors correct frataxin deficiency in a Friedreich ataxia mouse model.
No sample metadata fields
View SamplesMicroarray analysis of total RNA isolated from samples of circulating tumor cells from 7 patients before romidepsin infusion (0 hours), at 4 h after initiation of the infusion (4 hours) and 24 h after initiation of the infusion (24 hours).
MAPK pathway activation leads to Bim loss and histone deacetylase inhibitor resistance: rationale to combine romidepsin with an MEK inhibitor.
No sample metadata fields
View SamplesStreptococcus suis is a major swine pathogen that can be transmitted to humans causing severe symptoms. A large human outbreak was described in China, where approximately 25% out of 215 infected humans developed an unusual streptococcal toxic shock-like syndrome (STSLS). Albeit increased expression of inflammatory mediators following infection by the Chinese S. suis strain was suggested as responsible for STSLS case severity, the mechanisms involved are still poorly understood. In this study, we investigated the host innate immune response to infection by either one of 3 strains of S. suis: 89-1591 (Canadian, intermediate virulence), P1/7 (European, high virulence), and SC84 (Chinese, epidemic strain). Using Illumina microarray and validating those results with qPCR and Luminex assay, infected mice showed elevated expression of mainly pro-inflammatory chemokine and cytokine genes. Generally, pro-inflammatory genes were expressed at a higher level in mice infected with S. suis strain SC84 > P1/7 > 89-1591. Interestingly, IFN was expressed at much higher levels only in mice infected with the S. suis strain SC84, which could potentially explain some of the STSLS symptoms. IFN-KO mice infected with SC84 showed better survival than WT mice while no differences was seen in mice infected with highly virulent P1/7 strain. Overall, our results show an important role of IFN in S. suis infections and might explain in part the increased virulence of SC84 responsible for a recent outbreak in China.
Exacerbated type II interferon response drives hypervirulence and toxic shock by an emergent epidemic strain of Streptococcus suis.
Sex, Specimen part
View SamplesStreptococcus suis is a major swine pathogen that can be transmitted to humans causing severe symptoms. A large human outbreak was described in China, where approximately 25% out of 215 infected humans developed an unusual streptococcal toxic shock-like syndrome (STSLS). Albeit increased expression of inflammatory mediators following infection by the Chinese S. suis strain was suggested as responsible for STSLS case severity, the mechanisms involved are still poorly understood. In this study, we investigated the host innate immune response to infection by either one of 3 strains of S. suis: 89-1591 (Canadian, intermediate virulence), P1/7 (European, high virulence), and SC84 (Chinese, epidemic strain). Using Illumina microarray and validating those results with qPCR and Luminex assay, infected mice showed elevated expression of mainly pro-inflammatory chemokine and cytokine genes. Generally, pro-inflammatory genes were expressed at a higher level in mice infected with S. suis strain SC84 > P1/7 > 89-1591. Interestingly, IFN was expressed at much higher levels only in mice infected with the S. suis strain SC84, which could potentially explain some of the STSLS symptoms. IFN-KO mice infected with SC84 showed better survival than WT mice while no differences was seen in mice infected with highly virulent P1/7 strain. Overall, our results show an important role of IFN in S. suis infections and might explain in part the increased virulence of SC84 responsible for a recent outbreak in China.
Exacerbated type II interferon response drives hypervirulence and toxic shock by an emergent epidemic strain of Streptococcus suis.
Sex, Specimen part
View SamplesStreptococcus suis is a major swine pathogen that can be transmitted to humans causing severe symptoms. A large human outbreak was described in China, where approximately 25% out of 215 infected humans developed an unusual streptococcal toxic shock-like syndrome (STSLS). Albeit increased expression of inflammatory mediators following infection by the Chinese S. suis strain was suggested as responsible for STSLS case severity, the mechanisms involved are still poorly understood. In this study, we investigated the host innate immune response to infection by either one of 3 strains of S. suis: 89-1591 (Canadian, intermediate virulence), P1/7 (European, high virulence), and SC84 (Chinese, epidemic strain). Using Illumina microarray and validating those results with qPCR and Luminex assay, infected mice showed elevated expression of mainly pro-inflammatory chemokine and cytokine genes. Generally, pro-inflammatory genes were expressed at a higher level in mice infected with S. suis strain SC84 > P1/7 > 89-1591. Interestingly, IFN was expressed at much higher levels only in mice infected with the S. suis strain SC84, which could potentially explain some of the STSLS symptoms. IFN-KO mice infected with SC84 showed better survival than WT mice while no differences was seen in mice infected with highly virulent P1/7 strain. Overall, our results show an important role of IFN in S. suis infections and might explain in part the increased virulence of SC84 responsible for a recent outbreak in China.
Exacerbated type II interferon response drives hypervirulence and toxic shock by an emergent epidemic strain of Streptococcus suis.
Sex, Specimen part
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