Bacteria respond to osmotic stress by a substantial increase in the intracellular osmolality, adjusting their cell turgor for altered growth conditions. Using E. coli as a model organism we demonstrate here that bacterial responses to hyperosmotic stress specifically depend on the nature of osmoticum used. We show that increasing acute hyperosmotic NaCl stress above ~1.0 Os kg-1 causes a dose-dependent K+ leak from the cell, resulting in a substantial decrease in cytosolic K+ content and a concurrent accumulation of Na+ in the cell. At the same time, isotonic sucrose or mannitol treatment (non-ionic osmotica) results in a gradual increase of the net K+ uptake. Ion flux data is consistent with growth experiments showing that bacterial growth is impaired by NaCl at the concentration resulting in a switch from net K+ uptake to efflux. Microarray experiments reveal that about 40% of up-regulated genes shared no similarity in their responses to NaCl and sucrose treatment, further suggesting specificity of osmotic adjustment in E. coli to ionic- and non-ionic osmotica The observed differences are explained by the specificity of the stress-induced changes in the membrane potential of bacterial cells highlighting the importance of voltage-gated K+ transporters for bacterial adaptation to hyperosmotic stress.
Ion transport and osmotic adjustment in Escherichia coli in response to ionic and non-ionic osmotica.
No sample metadata fields
View SamplesThe goals were to investigate differences in gene expression between wild type and Gpr120 knockout mouse interscapular brown adipose tissue
The GPR120 agonist TUG-891 promotes metabolic health by stimulating mitochondrial respiration in brown fat.
Sex, Age, Specimen part
View SamplesThe goal of this study is to investigate if endogenous RNA in exosomes activates RIG-I through unshielding. Overall design: transcription profiling of exosomal RNA isolated from breast cancer patients before, during and after radiation therapy.
Exosome RNA Unshielding Couples Stromal Activation to Pattern Recognition Receptor Signaling in Cancer.
Subject
View SamplesThe goal of this study is to investigate if endogenous RNA in exosomes activates RIG-I through unshielding. Overall design: transcription profiling for exosomal RNA isolated from stroma cell (MRC5) or stroma/breast cancer cell co-culture (MRC5 and 1833).
Exosome RNA Unshielding Couples Stromal Activation to Pattern Recognition Receptor Signaling in Cancer.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesResponse of A549 cells treated with Aspergillus fumigatus wild type germinating conidia (WT_GC) or PrtT protease deficient mutant conidia (PrtT-GC) or inert acrylic 2-4 micron beads (Beads) for 8h
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesResponse of A549 cells treated with Aspergillus fumigatus wild type culture filtrate (WT-CF) or PrtT protease deficient mutant culture filtrate (PrtT-CF) for 8h
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesResponse of A549 cells treated with Aspergillus fumigatus germinating conidia (WT-GC) or culture filtrate (WT-CF) for 8h
PrtT-regulated proteins secreted by Aspergillus fumigatus activate MAPK signaling in exposed A549 lung cells leading to necrotic cell death.
Specimen part, Cell line, Treatment
View SamplesMicroarrays were used to examine gene expression changes that may be present in the fallopian tube epithelium of morphologically normal BRCA1 mutation positive and negative subjects. Fallopian tube epithelia has been implicated as an early point of origin for serous carcninoma. By examining the early events present in the microenvironment of this tissue between BRCA1 mutation carriers and non-carriers, we hoped to elucidate mechanisms that may lead to the development of epithelial ovarian cancer.
Identification of abrogated pathways in fallopian tube epithelium from BRCA1 mutation carriers.
Specimen part
View SamplesUsing gene expression profiling we characterize the global effect of p53 on the TLR5-mediated transcription in MCF7 cells. We found that combined activation of p53 and TLR5 pathways synergistically increases expression of over 200 genes, mostly associated with immunity and inflammation. The synergy was observed in several human cancer cells and primary lymphocytes.
p53 amplifies Toll-like receptor 5 response in human primary and cancer cells through interaction with multiple signal transduction pathways.
Cell line
View Samples