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GSE75359
Pseudomonas aeruginosa pao1
2 Downloadable Samples
Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Biofilms have been implicated in delayed wound healing, although the mechanisms by which biofilms impair wound healing are poorly understood. Many species of bacteria produce exotoxins and exoenzymes that may inhibit healing. In addition, oxygen consumption by biofilms, as well as responding leukocytes, may impede wound healing. In this study, we used oxygen microsensors to measure oxygen transects through in vitro-cultured biofilms, biofilms formed in vivo within scabs from a diabetic (db/db) mouse model, and ex vivo human chronic wound specimens. The results show that oxygen levels within mouse scabs had steep gradients that reached minima ranging from 17-72 mmHg on live mice and 6.4-1.1 mmHg on euthanized mice. The oxygen gradients in the mouse scabs were similar to those observed for clinical isolates cultured in vitro and for human ex vivo specimens. No oxygen gradients were observed for heat-killed mouse scabs, suggesting that active metabolism by the viable bacteria and host cells contributed to the reduced oxygen partial pressure of the scabs. To characterize the metabolic activities of the bacteria in the mouse scabs, we performed transcriptomics analyses of Pseudomonas aeruginosa biofilms associated with the db/db mice wounds using Affymetrix microarrays. The results demonstrated that the bacteria expressed genes for metabolic activities associated with cell growth. Interestingly, the transcriptome results indicated that the bacteria within the wounds also experienced oxygen-limitation stress. Among the bacterial genes that were expressed in vivo were genes associated with the Anr-mediated hypoxia-stress response. Other bacterial stress response genes highly expressed in vivo were genes associated with stationary-phase growth, osmotic stress, and RpoH-mediated heat shock stress. Overall, the results support the hypothesis that bacterial biofilms in chronic wounds promote chronicity by contributing to the maintenance of localized low oxygen tensions.
Publication Title
Microsensor and transcriptomic signatures of oxygen depletion in biofilms associated with chronic wounds.
Sample Metadata Fields
Specimen part, Disease, Time
View Samples- Pseudomonas aeruginosa pao1
- 2 Downloadable Samples
- Affymetrix Pseudomonas aeruginosa Array (paeg1a)
Description
Biofilms have been implicated in delayed wound healing, although the mechanisms by which biofilms impair wound healing are poorly understood. Many species of bacteria produce exotoxins and exoenzymes that may inhibit healing. In addition, oxygen consumption by biofilms, as well as responding leukocytes, may impede wound healing. In this study, we used oxygen microsensors to measure oxygen transects through in vitro-cultured biofilms, biofilms formed in vivo within scabs from a diabetic (db/db) mouse model, and ex vivo human chronic wound specimens. The results show that oxygen levels within mouse scabs had steep gradients that reached minima ranging from 17-72 mmHg on live mice and 6.4-1.1 mmHg on euthanized mice. The oxygen gradients in the mouse scabs were similar to those observed for clinical isolates cultured in vitro and for human ex vivo specimens. No oxygen gradients were observed for heat-killed mouse scabs, suggesting that active metabolism by the viable bacteria and host cells contributed to the reduced oxygen partial pressure of the scabs. To characterize the metabolic activities of the bacteria in the mouse scabs, we performed transcriptomics analyses of Pseudomonas aeruginosa biofilms associated with the db/db mice wounds using Affymetrix microarrays. The results demonstrated that the bacteria expressed genes for metabolic activities associated with cell growth. Interestingly, the transcriptome results indicated that the bacteria within the wounds also experienced oxygen-limitation stress. Among the bacterial genes that were expressed in vivo were genes associated with the Anr-mediated hypoxia-stress response. Other bacterial stress response genes highly expressed in vivo were genes associated with stationary-phase growth, osmotic stress, and RpoH-mediated heat shock stress. Overall, the results support the hypothesis that bacterial biofilms in chronic wounds promote chronicity by contributing to the maintenance of localized low oxygen tensions.
Publication Title
Microsensor and transcriptomic signatures of oxygen depletion in biofilms associated with chronic wounds.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus, Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Quantitative assays for human DNA and mRNA were used to examine the paradox that intravenously (IV) infused human multipotent stromal cells (hMSCs) can enhance tissue repair without significant engraftment. After 2 X 106 hMSCs were IV infused into mice, most of the cells were trapped as emboli in lung. The cells in lung disappeared with a half-life of about 24 hr but < 1,000 cells appeared in 6 other tissues. The hMSCs in lung up-regulated expression of multiple genes with a large increase in the anti-inflammatory protein TSG-6. After myocardial infarction, IV hMSCs but not hMSCs transduced with TSG-6 siRNA decreased inflammatory responses, reduced infarct size, and improved cardiac function. IV administration of recombinant TSG-6 also reduced inflammatory responses and reduced infarct size. The results suggest improvements in animal models and patients after IV infusions of MSCs are at least in part explained by activation of MSCs to secrete TSG-6.
Publication Title
Intravenous hMSCs improve myocardial infarction in mice because cells embolized in lung are activated to secrete the anti-inflammatory protein TSG-6.
Sample Metadata Fields
Specimen part, Disease
View Samples- Homo sapiens
- 18 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Staphylococcus aureus produces the cyclic dipeptides tyrvalin and phevalin (aureusimine A and B, respectively).
Publication Title
Phevalin (aureusimine B) production by Staphylococcus aureus biofilm and impacts on human keratinocyte gene expression.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Staphylococcus aureus
- 6 Downloadable Samples
- Affymetrix S. aureus Genome Array (saureus)
Description
AFN-1252 is an inhibitor of fatty acid biosynthesis. Gene expression profiles were generated by microarray analysis of S. aureus cells following treatment with AFN-1252, an inhibitor of fatty acid synthesis.
Publication Title
Perturbation of Staphylococcus aureus gene expression by the enoyl-acyl carrier protein reductase inhibitor AFN-1252.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 64 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 46 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
The mechanisms underlying natural variation in lifespan and ageing rate remain largely unknown.
Publication Title
Transcriptome analysis of a long-lived natural Drosophila variant: a prominent role of stress- and reproduction-genes in lifespan extension.
Sample Metadata Fields
Sex, Specimen part
View Samples- Escherichia coli k-12
- 27 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
The only target locus of transcription factor BglJ known to date is the bgl operon, and activation of bgl by BglJ requires RcsB. Transcription factor LeuO is involved in stress responses and known as antagonist of H-NS. To identifiy novel targets of BglJ, we overexpressed BglJ in Escherichia coli K12 and measured differential gene expression by performing DNA microarray analysis. Moreover, to analyze whether all targets of BglJ require RcsB, we overexpressed BglJ in an rcsB deletion background. In addition, we overexpressed LeuO to identifiy targets of LeuO.
Publication Title
RcsB-BglJ activates the Escherichia coli leuO gene, encoding an H-NS antagonist and pleiotropic regulator of virulence determinants.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Temporally restricted feeding is known to impact the circadian clock. This dataset shows the effects of temporally restricted feeding on the hepatic transcriptome.
Publication Title
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Restricted feeding impacts the hepatic circadian clock of WT mice. Cry1, Cry2 double KO mice lack a circadian clock and are thus expected to show rhythmical gene expression in the liver. Imposing a temporally restricted feeding schedule on these mice shows how the hepatic circadian clock and rhythmic food intake regulate rhythmic transcription in parallel
Publication Title
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
Sample Metadata Fields
No sample metadata fields
View Samples