Project description:The transcriptomic response of Jurkat T lymphoma cells to hydrogen peroxide was investigated to determine the global effects of hydrogen peroxide on cellular gene expression.
Project description:Adaptation to hydrogen peroxide in Saccharomyces cerevisiae is profiled with expression arrays. Adaptation describes the process in which a mild dose of toxin (in this case, hydrogen peroxide) is able to protect against a later acute dose. Here, we study two adaptive protocols (0.1 mM H2O2 and 0.1 + 0.4 mM H2O2) and one acute protocol (0.4 mM H2O2) to identify processes uniquely involved in adaptation. Predictions from these studies are validated in expression profiling of deletion mutants of the transcription factors Yap1, Mga2, and Rox1.
Project description:Accumulation of senescent cells is an important contributor to chronic inflammation upon aging. While the transcription factors driving the inflammatory phenotype of senescent cells have been extensively studies, the triggers of the pro-inflammatory pathways are still incompletely characterized. Here, we show that cells driven into senescence by different routes share a deficiency in RNA degradation activity most correlated with reduced expression of one or several subunits of the RNA exosome. A similar deficiency was also detected in cells exposed to oxidative stress, either acute, by treatment with hydrogen peroxide, or more long-term in a mouse model for mitochondrial suffering. Reciprocally, inactivation of RNA exosome activity reduced expression of mitochondrial genes while promoting senescence markers, suggesting that the RNAs accumulating as a consequence of the reduced turnover, have a function in promoting some aspects of the senescent phenotype. Consistent with this, we show that some of the RNA species detected in senescent cells are also produced during normal activation of immune cells and contain Alu sequences known to trigger an innate immune response. We propose that these RNA species participate in driving and maintaining the permanent inflammatory state characteristic of cellular senescence.
Project description:Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. The release of the pore-forming cholesterol-dependent cytolysin (CDC) pneumolysin (PLY) and hydrogen peroxide (H2O2), a physiological metabolite, is an important virulence determinant of pneumococci.
Project description:In this experiment we tested the transcriptome of transgenic Arabidopsis seedlings (5-day-old) constitutively expressing the zinc-finger protein Zat12 (At5g59820) under the control of the 35S-CaMV promoter (Zat12). The transcriptome of these seedlings was compared to that of wild type seedlings grown under the same conditions (WT) and to that of wild type seedlings grown under the same conditions and subjected to a hydrogen peroxide stress (WT+H2O2). Hydrogen peroxide treatment was performed by applying 20 mM hydrogen peroxide for 1 hour. In parallel to these experiments transgenic plants expressing Zat12 were subjected to a similar hydrogen peroxide stress (Zat12+H2O2). All treatments were performed with similar size and age seedlings grown in liquid culture (MS) and sampled at the same time as described by Davletova et al., 2005. Experimenter name = Ron Mittler Experimenter phone = 1-775-784-1384 Experimenter fax = 1-775-784-1650 Experimenter department = Dept. of Biochemistry Experimenter institute = University of Nevada Experimenter address = MS200 Experimenter address = Reno Experimenter address = Nevada Experimenter zip/postal_code = 89557 Experimenter country = USA Keywords: genetic_modification_design; stimulus_or_stress_design
Project description:Green plants are more robust to hydrogen peroxide (H2O2) stress and contain high endogeneous H2O2 levels which is generated during photorespiration and photosynthesis. Therefore, exgeneous H2O2 application mostly impose oxidative stress. To reduce endogenous H2O2 background, we adopted a strategy which is to grow Arabidopsis seedlings in the dark to eliminate light-induced H2O2 production, thus to reduce the endogenous H2O2 level. Exogenous H2O2 was then applied to induce transcriptome changes. Global gene expression is studied and compared between samples collected under 7d dark, 7d H2O2 treatment under dark and 7d light conditions.
Project description:In this experiment we tested the transcriptome of transgenic Arabidopsis seedlings (5-day-old) constitutively expressing the zinc-finger protein Zat12 (At5g59820) under the control of the 35S-CaMV promoter (Zat12). The transcriptome of these seedlings was compared to that of wild type seedlings grown under the same conditions (WT) and to that of wild type seedlings grown under the same conditions and subjected to a hydrogen peroxide stress (WT+H2O2). Hydrogen peroxide treatment was performed by applying 20 mM hydrogen peroxide for 1 hour. In parallel to these experiments transgenic plants expressing Zat12 were subjected to a similar hydrogen peroxide stress (Zat12+H2O2). All treatments were performed with similar size and age seedlings grown in liquid culture (MS) and sampled at the same time as described by Davletova et al., 2005. Experimenter name = Ron Mittler; Experimenter phone = 1-775-784-1384; Experimenter fax = 1-775-784-1650; Experimenter department = Dept. of Biochemistry; Experimenter institute = University of Nevada; Experimenter address = MS200; Experimenter address = Reno; Experimenter address = Nevada; Experimenter zip/postal_code = 89557; Experimenter country = USA Experiment Overall Design: 12 samples were used in this experiment
Project description:Excessive levels of reactive oxygen species (ROS) cause cellular stress through damage to all classes of macromolecules and result in cell death. However, ROS can also act as signaling molecules in various biological processes. In plants, ROS signaling has been documented in environmental stress perception, plant development and cell death amongst others. Knowledge on the regulatory events governing ROS signal transduction is however still scratching the surface. To further elucidate the transcriptional response and regulation upon ROS accumulation we supplemented Arabidopsis seedlings with a 10mM hydrogen peroxide (H2O2) solution to trigger oxidative stress. After growth of 7 days, hydrogen peroxide (H2O2) was added to a final concentration of 10mM. Control plants were treated with the same volume of H2O. Seedlings were grown for 24h under the same controlled conditions. Design: 3 replicates x 2 conditions (7+1 day H2O or 7+1 day H2O2)
Project description:Reactive oxygen species such as hydrogen peroxide occur in all aerobically living organisms. Oxidative stress during fermentation can impair the fitness of the production host and the quality of the product. B. pumilus has been described as highly resistant to hydrogen peroxide. The response of exponentially growing B. pumilus cells to hydrogen peroxide was studied.
Project description:In muscle, reactive oxygen species (ROS) generation increases with strenuous activity, chronic unloading, and inflammatory stimuli; skeletal muscle function is very sensitive to ROS; and there are redox-sensitive signaling pathways. Using myogenic cell cultures, we asked whether hydrogen peroxide (H2O2) induces adaptive changes in skeletal muscle gene expression. H2O2 downregulated or failed to induce antioxidant or apoptotic genes in the myotubes. Instead, H2O2 changed the expression of genes for cytosolic and mitochondrial enzymes, and upregulated inflammatory mediators. Finally, H2O2 had a mostly inhibitory effect on the expression of many transcription factors. The results indicate that mild oxidative stress may induce an adaptive response in skeletal muscle without antioxidant upregulation or apoptosis. Keywords: Gene Expression, C2C12 Myotubes, Oxidative Stress, Adaptation