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GSE55662
Escherichia coli k-12
8 Downloadable Samples
Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here we demonstrate that inactivation of a central regulator of iron homeostasis (fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated a substantial reorganization of the Fur regulon in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, over-expression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, while inhibition of the SOS response-mediated mutagenesis had no such effect in fur deficient population. In sum, our work revealed the central role of iron metabolism in de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies.
Publication Title
Perturbation of iron homeostasis promotes the evolution of antibiotic resistance.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Severe infections and sepsis is an increasing clinical problem that cause prolonged morbidity and substantial mortality. At present, antibiotics are essentially the only pharmacological treatment for sepsis. The incidence of antibiotic resistance is increasing and it is therefore critical to find new therapies for sepsis. Staphylococcus aureus (S. aureus) is a major cause of septic mortality. Neutrophils play a major role in defense against bacterial infections. We have recently shown that a saturated high fat diet decreases survival in septic mice, but the mechanisms behind remain elusive. The aim of the present study was to investigate how the dietary fat composition affects survival and neutrophils function after experimental septic infection in mice. We found that, after S. aureus infection, mice fed polyunsaturated high fat diet (HFD/P) for 8 weeks had increased septic survival and decreased bacterial load compared with mice fed saturated HFD (HFD/S), and similar to that of mice given low fat diet (LFD). Furthermore, uninfected mice fed HFD/P had increased number of Ly6G+ neutrophils in bone marrow. In addition, mice fed HFD/P had a higher number Ly6G+ neutrophils recruited to the site of inflammation after peritoneal injection of thioglycollate. In conclusion, polyunsaturated dietary fat increased both survival and the efficiency of the bacterial clearance during septic S. aureus infection. Moreover, this diet enhanced the number and chemotaxis of neutrophils, a key component of the immune response to S. aureus infections.
Publication Title
Dietary polyunsaturated fatty acids increase survival and decrease bacterial load during septic Staphylococcus aureus infection and improve neutrophil function in mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The role of SPROUTY2 (SPRY2) in human colon cancer is controversial. Our data support a tumorigenic action of SPRY2. We use microarrays to identify SPRY2 target genes in human SW480 ADH colon carcinoma cell line.
Publication Title
SPROUTY-2 represses the epithelial phenotype of colon carcinoma cells via upregulation of ZEB1 mediated by ETS1 and miR-200/miR-150.
Sample Metadata Fields
Cell line
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