Expression data from yeast wild type (WT) and sod1Δ strains after treatment with hydrogen peroxide (H2O2)
ABSTRACT: An important cellular defense mechanism against oxidative stress is the induction of genes involved in ROS resistance and DNA damage repair. Under normal conditions, Sod1 is localized mainly in the cytosol. However, we found that Sod1 translocates into the nucleus after oxidative stress. To address the physiological role of Sod1, we performed DNA microarray analysis of global gene expression in wild type (WT) and sod1Δ cells before and after treatment with H2O2. Early log phase WT and sod1Δ cells were treated with or without H2O2 for 20 min and RNA samples were extracted and subjected to hybridization on Affymetrix microarrays. We then compared the dataset of WT +/- H2O2 with SOD1 deleted cells +/- H2O2 to identify the H2O2-responsive genes whose induction was attenuated in sod1Δ cells by more than 50%.
Project description:FVB mice were engineered to express wild-type human cyclin E under control of the human surfactant C promoter (CEO mice; Ma et al, PNAS 2007). These mice develop spontaneous lung tumors, which were shown to be adenocarcinoma by histological analysis. Here we compare whole-genome RNA expression levels between the tumors and normal lung of 4 CEO mice as well as 4 nontransgenic animals. RNA was isolated from the lungs of 4 FVB mice and adjacent normal and tumor tissue from 4 FVB transgenes harboring human surfactant protein C- driven wild-type human cyclin E, all 7-11 months in age. These samples were divided into 3 groups of four, and 12 independent hybridizations were performed for analysis with Affymetrix GeneChip Mouse 430 2.0 arrays.
Project description:Cells counteract oxidative stress by altering metabolism, cell cycle and gene expression. However, the mechanisms that coordinate these adaptations are only marginally understood. Here we provide evidence that timing of these responses in yeast requires export of the polyamines spermidine and spermine. We show that during hydrogen peroxide (H2O2) exposure, the polyamine transporter Tpo1 controls spermidine and spermine concentrations and mediates induction of antioxidant proteins, including Hsp70, Hsp90, Hsp104 and Sod1. Moreover, Tpo1 determines a cell cycle delay during adaptation to increased oxidant levels, and affects H2O2 tolerance. Thus, central components of the stress response are timed through Tpo1‐controlled polyamine export.
Project description:The bacteriostatic and bactericidal effects and the corresponding expression profiles of Mycobacterium tuberculosis to representative oxidative and nitrosative stresses were investigated by growth and survival studies and whole genome expression analysis. The response of M. tuberculosis to a range of hydrogen peroxide (H2O2) concentrations tended to fall into three distinct categories: (1) low level exposure resulted in induction of few H2O2 sensitive genes, (2) intermediate exposure resulted in massive transcriptional changes without an effect on growth or survival, and (3) high exposure resulted in a muted transcriptional response and eventual death. Nitric oxide (NO) exposure initiated much of the same transcriptional response as H2O2. However, unlike H2O2 exposure, NO exposure affected a dose-dependent bacteriostatic activity without killing and induction of dormancy-related genes. Included in the shared response to H2O2 and NO was the induction of genes encoding oxidative stress detoxification and iron-sulfur cluster repair functions. Expression of several key oxidative stress defense genes was constitutive, or increased moderately from an already elevated level, suggesting bacilli that are continually primed for oxidative stress defense. Deletion of the known oxidative stress responsive regulator, FurA, resulted in the constitutive expression of furA, katG, and Rv1907c; while other genes do not appear to be solely controlled by FurA. In contrast to Escherichia coli, M. tuberculosis appears highly resistant to DNA damage-dependent killing caused by low mill molar levels of H2O2. Furthermore, instead of limiting access to iron to prevent hydroxyl radical formation from H2O2 and thus DNA damage, M. tuberculosis induced iron uptake genes in response to H2O2 and NO. Set of arrays that are part of repeated experiments Compound Based Treatment: H2O2 or DETA/NO treatment
Project description:Fetal growth restriction (FGR) develops when fetal nutrient availability is compromised and increases the risk for perinatal complications and predisposes for offspring obesity, diabetes and cardiovascular disease later in life. Emerging evidence implicates changes in placental function in altered fetal growth and the subsequent development of adult disease. The susceptibility for disease in response to an adverse intrauterine environment differs distinctly between boys and girls, with girls typically having better outcomes. Here, we test the hypothesis that regulation of the placental transcriptome by moderate nutrient reduction is dependent on fetal sex. We used a non-human primate model of FGR in which maternal global food intake is reduced by 30% starting at gestational day (GD) 30. At GD 165 (term = GD 183) placental genome expression profiling was carried out followed by bioinformatics including pathway and network analysis. Surprisingly, there was no coordinated placental molecular response to decreased nutrient availability when analyzing the data without accounting for fetal sex. In contrast, female placentas exhibited a highly coordinated response that included up-regulation of genes in networks, pathways and functional groups related to programmed cell death and down-regulation of genes in networks, pathways and functional groups associated with cell proliferation. These changes were not apparent in the male placentas. Our data support the concept that female placentas initiate complex adaptive responses to an adverse intrauterine environment, which may contribute to increased survival and better pregnancy outcomes in girls. Total RNA obtained from 165dGA control female (n=3), control male (n=3), nutrient restricted female (n=3), and nutrient restricted male (n=3) pregnancies.
Project description:We measured gene expression differences in the extensor digitorum longus (edl) skeletal muscle between wild-type and mice lacking Cu, Zn-superoxide dismutase to determine the effect of chronic oxidative stress on skeletal muscle. We analyzed 4 edl samples from WT mice and 4 samples from the SOD1 knockouts.
Project description:Background: During gut colonization, the enteric pathogen C. jejuni has to surmount the toxic effects of reactive oxygen species produced by its own metabolism, by the host immune system and by the intestinal microflora. Elucidation of C. jejuni oxidative stress defense mechanisms is critical for understanding Campylobacter pathophysiology. Results: The mechanisms of oxidative stress defenses in Campylobacter jejuni were characterized by transcriptional profiling, genes mutagenesis, and phenotypic analysis. The transcriptome changes, in response to H2O2, cumene hydroperoxide, or menadione exposure, were found to be oxidant specific and revealed the differential expression of genes belonging to a variety of biological pathways, from the classical oxidative stress defense systems, to the heat shock response, DNA repair and metabolism, fatty acid and capsule biosynthesis, and multidrug efflux pumps. To define the peroxide sensing regulator PerR, an isogenic mutant was constructed and its transcriptome profile compared to the wild-type strain. Sixty-six genes were found to belong to the PerR regulon. PerR appear to regulate gene expression both dependently and independently of the presence of iron and/or H2O2. The perR mutant was affected in its motility and attenuated in the chick colonization model. Mutagenic and phenotypic studies of the superoxide disumutase SodB, the alkyl-hydroxyperoxidase AhpC, and the catalase KatA, revealed their role in oxidative stress defenses and chick gut colonization. Conclusion: This study reveals the interplay between PerR, the iron metabolism and the oxidative stress defenses and highlights their role in the colonization and/or survival of C. jejuni in the chick cecum. Keywords: Transcriptional response to 3 oxidants (H2O2, menadione and cumene hydroperoxide) and characterization of the perR regulon (comparison of the transciptomes from the wild-type and perR mutant). To investigate the transcriptional responses of C. jejuni to oxidant exposure, hydrogen peroxide (H2O2), cumene hydroperoxide (CHP), or menadione sodium bisulfite (MND) was added to the 50 ml broth at a final concentration of 1 mM. The same amount of water or DMSO was added to the bacterial culture that served as reference samples for the transcriptional profile study in response to H2O2, MND or CHP. Furthermore, to investigate the transcriptional response of C. jejuni to H2O2 exposure in the presence of excess iron, ferrous sulfate was added to the bacterial culture at a final concentration of 40 µM, 15 min prior to H2O2 exposure. Ten minutes after the addition of the oxidant, total RNA was extracted and processed for microarray hybridization. To identify the PerR regulon, the wild-type strain C. jejuni NCTC 11168 and the perR mutant were grown in 500 ml flasks containing 250 ml of MEMα medium. At mid-log phase, 50 ml of the cultures were transferred to 100 ml flasks and ferrous sulfate and/or H2O2 were added . Ten minutes following the addition of H2O2 the cells were collected and the total RNA extracted.
Project description:H2O2 is considered to function as a ubiquitous intracellular messenger in addition to oxidative stress molecule. This dual role of H2O2 is based on the distinct responses against the different concentration, which is low dose (sub-toxic) and high dose (toxic). In this study we performed the transcription response of low and high dosage of H2O2 on Candida albicans
Project description:Quorum sensing controls the expression of multiple virulence factors. PA14 genes lasR and rhlR are necessary for quorum sensing via homoserine lactones. A PA14 lasR rhlR deficient mutant exhibits a reduced oxidative stress response. Here we conducted a microarray to determine oxidative stress response gene regulation mediated by the homoserine lactone quorum sensing circuits. A PA14 lasR rhlR deficient mutant was compared to the wild-type with and without H2O2 stress.
Project description:The WWOX gene spans chromosomal fragile site FRA16D, a region of DNA instability in cancer. While WWOX has some tumor suppressor characteristics, its normal role and functional contribution to cancer are unclear. Drosophila homozygous Wwox mutants are viable with no discernable phenotype. Drosophila Wwox interactors, identified by proteomics and micro-array analyses, mainly have roles in aerobic metabolism. Functional relationships between Wwox and either isocitrate dehydrogenase (IDH) or superoxide dismutase 1 (Sod1) were confirmed by phenotype modification, including Sod1 ‘crinkled-wing’, indicative of oxidative stress response. Endogenous reactive oxygen species levels reflect Wwox levels in Drosophila. WWOX mRNA levels in Drosophila and human cells correlate with IDH and Sod1 levels. Wwox therefore contributes to pathways involving glucose metabolism and oxidative stress response. Drosophila embryos were harvested between 4-8hrs and total RNA isolated to look for gene-expression differences induced by the presence of one of two altered Wwox alleles relative to wild-type. The two alleles were Wwox (a null mutation generated by homologous recombination) and Wwoxf04545 carrying a pBac insertion in exon 2 (O’Keefe et al., 2005, 2007). Embryo pools were isolated in triplicate, providing 3 biological replicates.
Project description:Thiol peroxidase (TpxD) is one of the key enzymes used to cope with oxidative stress conditions in S. pneumoniae. Previously, we demonstrated that TpxD expression is modulated in response to H2O2 and is involved in the regulation of the psa operon. In the current study, we focus on TpxD function as a sensor and global regulator in the bacterial response to H2O2. By using microarray assays, we show that TpxD expression is necessary for the activation of bacterial global gene response to H2O2. The mechanism underlying TpxD regulatory function was further elucidated by replacing the catalytic cysteine (Cys58) with alanine (Ala58) in TpxD. This point mutation prevented tpxD up-regulation by H2O2, as well as the effect of H2O2 on additional genes that were affected by H2O2 in the WT but not in ∆tpxD, signifying that this cysteine is crucial for TpxD signaling activity. We then tried to identify a candidate transcription factor which regulates tpxD expression under H2O2 stress. Bioinformatics analysis identified a putative CodY 15 bp binding site in the proximal upstream region of tpxD coding sequence. Genetic engineering techniques and EMSA assays confirmed the presence of an active CodY box. Indeed, no up-regulation of TpxD was noticed in ∆codY challenged with H2O2. These data identify CodY as the transcription factor modulating tpxD expression under H2O2 stress. We propose a model of gene regulation under oxidative stress conditions which places TpxD as an intermediary between H2O2 and the global bacterial response to oxidative stress. This SuperSeries is composed of the SubSeries listed below. Overall design: Refer to individual Series