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Response of Saccharomyces cerevisiae to the stimulation of lipopolysaccharide.

Shen L, Li Y, Jiang L, Wang X - PLoS ONE (2014)

Bottom Line: In this study, we found that lipopolysaccharide-treated S. cerevisiae cells could be stained by methylene blue, but did not die.Significantly regulated genes (460 up-regulated genes and 135 down-regulated genes) in lipopolysaccharide-treated S. cerevisiae cells were analyzed on Gene Ontology, and used to establish physical protein-protein interaction network and protein phosphorylation network.Based on these analyses, most of the regulated genes in lipopolysaccharide-treated S. cerevisiae cells were related to cell wall, membrane, peroxisome and mitochondrion.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; School of Biotechnology, Jiangnan University, Wuxi, China.

ABSTRACT
Lipopolysaccharide, known as endotoxin, can stimulate potent host immune responses through the complex of Toll-like-receptor 4 and myeloid differentiation protein 2; but its influence on Saccharomyces cerevisiae, a model organism for studying eukaryotes, is not clear. In this study, we found that lipopolysaccharide-treated S. cerevisiae cells could be stained by methylene blue, but did not die. Transcriptional profiling of the lipopolysaccharide-treated S. cerevisiae cells showed that 5745 genes were modulated: 2491 genes up-regulated and 3254 genes down-regulated. Significantly regulated genes (460 up-regulated genes and 135 down-regulated genes) in lipopolysaccharide-treated S. cerevisiae cells were analyzed on Gene Ontology, and used to establish physical protein-protein interaction network and protein phosphorylation network. Based on these analyses, most of the regulated genes in lipopolysaccharide-treated S. cerevisiae cells were related to cell wall, membrane, peroxisome and mitochondrion. Further experiments demonstrated that lipopolysaccharide stimulation caused the exposure of phosphatidylserine and the increase of mitochondrial membrane potential in S. cerevisiae cells, but levels of intracellular reactive oxygen species and metacaspase activation were not increased. This study demonstrated that lipopolysaccharide stimulation causes significant changes in S. cerevisiae cells, and the results would contribute to understand the response of eukaryotic cells to lipopolysaccharide stimulation.

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Related in: MedlinePlus

Effect of LPS stimualtion to S. cerevisiae BY4742.A. Methylene blue staining of S. cerevisiae BY4742 cells treated with different concentrations of LPS and observed using light microscopy. The solid bars in the photos indicate 10 µm. The concentrations of LPS were listed on top of the photos. B. Drop test showed that S. cerevisiae BY4742 cells treated with 1.0 mg mg/mL LPS were not dead.
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pone-0104428-g001: Effect of LPS stimualtion to S. cerevisiae BY4742.A. Methylene blue staining of S. cerevisiae BY4742 cells treated with different concentrations of LPS and observed using light microscopy. The solid bars in the photos indicate 10 µm. The concentrations of LPS were listed on top of the photos. B. Drop test showed that S. cerevisiae BY4742 cells treated with 1.0 mg mg/mL LPS were not dead.

Mentions: Methylene blue, a heterocyclic aromatic chemical compound, can be used as an indicator to determine if yeast cells are alive [18], [35]. Viable yeast cells usually cannot be stained by methylene blue because their membranes cannot be penetrated. The dead or injured yeast cells can be stained because their membranes are damaged and cannot keep the methylene blue from penetrating. In this study, three different methylene blue solutions [18]–[20] were used to stain S. cerevisiae BY4742 cells. At the same methylene blue concentration (3.0 mg/mL), none of the three methylene blue solutions could stain S. cerevisiae BY4742 cells; however, all three methylene blue solutions could stain the LPS-treated BY4742 cells. The staining was pH independent because pH values of the three methylene blue solutions are different. Fig. 1A showed the microscopic pictures of S. cerevisiae BY4742 cells exposed to different concentrations of LPS and stained by Loeffler's alkaline methylene blue solution. The proportion of the cells that could be stained by methylene blue increased with the increase of LPS concentration in the mixture. After exposure to 1.0 mg/mL LPS, around 5×108S. cerevisiae cells in 1 mL mixture (OD600 = 2.0) could be all stained by methylene blue. The staining of LPS-treated S. cerevisiae BY4742 cells suggests that the cells were either dead or injured after LPS treatment because methylene blue could not penetrate normal cell's membrane.


Response of Saccharomyces cerevisiae to the stimulation of lipopolysaccharide.

Shen L, Li Y, Jiang L, Wang X - PLoS ONE (2014)

Effect of LPS stimualtion to S. cerevisiae BY4742.A. Methylene blue staining of S. cerevisiae BY4742 cells treated with different concentrations of LPS and observed using light microscopy. The solid bars in the photos indicate 10 µm. The concentrations of LPS were listed on top of the photos. B. Drop test showed that S. cerevisiae BY4742 cells treated with 1.0 mg mg/mL LPS were not dead.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126697&req=5

pone-0104428-g001: Effect of LPS stimualtion to S. cerevisiae BY4742.A. Methylene blue staining of S. cerevisiae BY4742 cells treated with different concentrations of LPS and observed using light microscopy. The solid bars in the photos indicate 10 µm. The concentrations of LPS were listed on top of the photos. B. Drop test showed that S. cerevisiae BY4742 cells treated with 1.0 mg mg/mL LPS were not dead.
Mentions: Methylene blue, a heterocyclic aromatic chemical compound, can be used as an indicator to determine if yeast cells are alive [18], [35]. Viable yeast cells usually cannot be stained by methylene blue because their membranes cannot be penetrated. The dead or injured yeast cells can be stained because their membranes are damaged and cannot keep the methylene blue from penetrating. In this study, three different methylene blue solutions [18]–[20] were used to stain S. cerevisiae BY4742 cells. At the same methylene blue concentration (3.0 mg/mL), none of the three methylene blue solutions could stain S. cerevisiae BY4742 cells; however, all three methylene blue solutions could stain the LPS-treated BY4742 cells. The staining was pH independent because pH values of the three methylene blue solutions are different. Fig. 1A showed the microscopic pictures of S. cerevisiae BY4742 cells exposed to different concentrations of LPS and stained by Loeffler's alkaline methylene blue solution. The proportion of the cells that could be stained by methylene blue increased with the increase of LPS concentration in the mixture. After exposure to 1.0 mg/mL LPS, around 5×108S. cerevisiae cells in 1 mL mixture (OD600 = 2.0) could be all stained by methylene blue. The staining of LPS-treated S. cerevisiae BY4742 cells suggests that the cells were either dead or injured after LPS treatment because methylene blue could not penetrate normal cell's membrane.

Bottom Line: In this study, we found that lipopolysaccharide-treated S. cerevisiae cells could be stained by methylene blue, but did not die.Significantly regulated genes (460 up-regulated genes and 135 down-regulated genes) in lipopolysaccharide-treated S. cerevisiae cells were analyzed on Gene Ontology, and used to establish physical protein-protein interaction network and protein phosphorylation network.Based on these analyses, most of the regulated genes in lipopolysaccharide-treated S. cerevisiae cells were related to cell wall, membrane, peroxisome and mitochondrion.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; School of Biotechnology, Jiangnan University, Wuxi, China.

ABSTRACT
Lipopolysaccharide, known as endotoxin, can stimulate potent host immune responses through the complex of Toll-like-receptor 4 and myeloid differentiation protein 2; but its influence on Saccharomyces cerevisiae, a model organism for studying eukaryotes, is not clear. In this study, we found that lipopolysaccharide-treated S. cerevisiae cells could be stained by methylene blue, but did not die. Transcriptional profiling of the lipopolysaccharide-treated S. cerevisiae cells showed that 5745 genes were modulated: 2491 genes up-regulated and 3254 genes down-regulated. Significantly regulated genes (460 up-regulated genes and 135 down-regulated genes) in lipopolysaccharide-treated S. cerevisiae cells were analyzed on Gene Ontology, and used to establish physical protein-protein interaction network and protein phosphorylation network. Based on these analyses, most of the regulated genes in lipopolysaccharide-treated S. cerevisiae cells were related to cell wall, membrane, peroxisome and mitochondrion. Further experiments demonstrated that lipopolysaccharide stimulation caused the exposure of phosphatidylserine and the increase of mitochondrial membrane potential in S. cerevisiae cells, but levels of intracellular reactive oxygen species and metacaspase activation were not increased. This study demonstrated that lipopolysaccharide stimulation causes significant changes in S. cerevisiae cells, and the results would contribute to understand the response of eukaryotic cells to lipopolysaccharide stimulation.

Show MeSH
Related in: MedlinePlus