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GSE19315
Homo sapiens
9 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Shiga toxins (Stxs) are bacterial cytotoxins produced by the enteric pathogens Shigella dysenteriae serotype 1 and some serotypes of Escherichia coli that cause bacillary dysentery and hemorrhagic colitis, respectively. To date, approaches to studying the capacity of Stxs to alter gene expression in intoxicated cells have been limited to individual genes. However, it is known that many of the signaling pathways activated by Stxs regulate the expression of multiple genes in mammalian cells. To expand the scope of analysis of gene expression and to better understand the underlying mechanisms for the various effects of Stxs on cell functions, we carried out comparative microarray analyses to characterize the global transcriptional response of human macrophage-like THP-1 cells to Shiga toxin type 1 (Stx1) and LPS. Data were analyzed using a rigorous combinatorial approach with three separate statistical algorithms. Thirty-six genes met the criteria of up-regulated expression in response to Stx1 treatment with 14 genes uniquely up-regulated by Stx1. Microarray data were validated by real time RT-PCR for genes encoding Egr-1 (transcriptional regulator), COX-2 (inflammation), and DUSP1, 5 and 10 (regulation of MAPK signaling). Stx1-mediated signaling through ERK1/2 and Egr-1 appears to be involved in the increased expression of the proinflammatory mediator TNF-. Activation of COX-2 expression is associated with the increased production of proinflammatory and vasoactive eicosanoids. However, the capacity of Stx1 to increase the expression of genes encoding phosphatases suggests that mechanisms to dampen the macrophage proinflammatory response may be built into host response to the toxins.
Publication Title
Global transcriptional response of macrophage-like THP-1 cells to Shiga toxin type 1.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Arabidopsis thaliana
- 24 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation.
Publication Title
A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) phr1 mutant plants expressing PHR1 in presence of cicloheximide, that inhibit protein translation, thus preventing any effect of PHR1 on the expression of indirect targets. Results show the primary target genes of PHR1 in the responses to Pi starvation.
Publication Title
A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 18 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We performed a transcriptomic analysis of Pi-starvation and recovery after resupplying Pi in Arabidopsis thaliana (Columbia-0) wild type plants and double mutant spx1,spx2. Results show that SPX1 is a Pi-dependent inhibitor of the transcription factor PHR1, a central regulatory protein in the control of transcriptional responses to Pi starvation.
Publication Title
SPX1 is a phosphate-dependent inhibitor of Phosphate Starvation Response 1 in Arabidopsis.
Sample Metadata Fields
Age, Specimen part
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
We describe a new mutant allele of the ACTIN2 gene with enhanced actin dynamics, displaying a broad array of twisting and bending phenotypes that resemble BR-treated plants. Moreover, auxin transcriptional regulation is enhanced on the mutant background, supporting the idea that shaping actin filaments is sufficient to modulate BR-mediated auxin responsiveness. The actin cytoskeleton thus functions as a scaffold for integration of auxin and BR signaling pathways.
Publication Title
Role of actin cytoskeleton in brassinosteroid signaling and in its integration with the auxin response in plants.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Analysis of differentiated Caco-2 intestinal epithelial cell line cocultured with probiotics L. acidophilus NCFM, B. lactis 420, L. salivarius Ls-33 bacterial cells or treated with cell-free supernatant, and with E. coli O157:H7 cell-free supernatant. Lactobacillus and Bifidobacterium are important genera suggested to be beneficial for human health and E. coli O157:H7 is a pathogen causing hemorrhagic colitis and hemolytic uremic syndrome. Results provide insight into the mechanisms underlying the beneficial effects of probiotics on intestinal epithelial cells and a comparison to pathogenic E. coli.
Publication Title
Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bifidobacterium lactis and Escherichia coli.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 12 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Stress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter. We identify WRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing.
Publication Title
WRKY6 transcription factor restricts arsenate uptake and transposon activation in Arabidopsis.
Sample Metadata Fields
Time
View Samples- Pseudomonas aeruginosa pao1
- 8 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Anticipating the risk for infectious disease during space exploration and habitation is a critical factor to ensure safety, health and performance of the crewmembers. As a ubiquitous environmental organism that is occasionally part of the human flora, Pseudomonas aeruginosa could pose a health hazard for the immuno-compromised astronauts. In order to gain insights in the behavior of P. aeruginosa in spaceflight conditions, two spaceflight-analogue culture systems, i.e. the rotating wall vessel (RWV) and the random position machine (RPM), were used. Microarray analysis of P. aeruginosa PAO1 grown in the low shear modeled microgravity (LSMMG) environment of the RWV compared to the normal gravity control (NG), revealed a regulatory role for AlgU (RpoE). Specifically, P. aeruginosa cultured in LSMMG exhibited increased alginate production and up-regulation of AlgU-controlled transcripts, including those encoding stress-related proteins. This study also shows the involvement of Hfq in the LSMMG response, consistent with its previously identified role in the Salmonella LSMMG- and spaceflight response. Furthermore, cultivation in LSMMG increased heat- and oxidative stress resistance and caused a decrease in the culture oxygen transfer rate. Interestingly, the global transcriptional response of P. aeruginosa grown in the RPM was similar to that in NG. The possible role of differences in fluid mixing between the RWV and RPM is discussed, with the overall collective data favoring the RWV as the optimal model to study the LSMMG-response of suspended cells. This study represents a first step towards the identification of specific virulence mechanisms of P. aeruginosa activated in response to spaceflight-analogue conditions, and could direct future research regarding the risk assessment and prevention of Pseudomonas infections for the crew in flight and the general public.
Publication Title
Response of Pseudomonas aeruginosa PAO1 to low shear modelled microgravity involves AlgU regulation.
Sample Metadata Fields
No sample metadata fields
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Mitogen-activated dual-specificity MAPK phosphatases are important negative regulators in the MAPK signalling pathways responsible for many essential processes in plants. In a screen for mutants with reduced organ size we have identified a mutation in the active site of the dual-specificity MAPK phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) that we named tinkerbell (tink) due to its small size. Analysis of the tink mutant indicates that IBR5 acts as a novel regulator of organ size that changes the rate of growth in petals and leaves. Organ size and shape regulation by IBR5 acts independently of the KLU growth-regulatory pathway. Microarray analysis of tink/ibr5-6 mutants identified a likely role for this phosphatase in male gametophyte development. We show that IBR5 may influence the size and shape of petals through auxin and TCP growth regulatory pathways.
Publication Title
The Tinkerbell (Tink) Mutation Identifies the Dual-Specificity MAPK Phosphatase INDOLE-3-BUTYRIC ACID-RESPONSE5 (IBR5) as a Novel Regulator of Organ Size in Arabidopsis.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 18 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
We compared gene expression in the small intestine (ileum) of mice that were either (i) germ-free, (ii) colonized with a conventional mouse cecal microbiota, (iii) colonized with a conventional zebrafish gut microbiota, or (iv) colonized with Pseudomonas aeruginosa PAO1.
Publication Title
Reciprocal gut microbiota transplants from zebrafish and mice to germ-free recipients reveal host habitat selection.
Sample Metadata Fields
Specimen part
View Samples