Project description:Interventions: To administere eicosapentaenoic acid before surgery
Primary outcome(s): To evaluate the ability of EPA to suppress oxidative stress when administered before surgery.
Study Design: Single arm Non-randomized
Project description:The TET-family enzymes (TETs) convert methylcytosine to hydroxymethylcytosine, a lately discovered epigenetic modification that can modulate transcription. While recent reports suggest that TETs may play a role in response to oxidative stress, this role remains uncertain. Here we show that Tet1 is sensitive to peroxide and report a global decrease in hydroxymethylcytosine in cells treated with BSO and in the intestinal epithelium of mice lacking the major antioxidant enzymes glutathione peroxidases 1 and 2. Furthermore, genome-wide profiling revealed differentially hydroxymethylated regions in genes involved in responses to oxidative stress. Intriguingly, a considerable proportion of these regions lie in genes encoding microRNAs predicted to target transcripts involved in oxidative stress response. This work thus demonstrates a profound effect of oxidative stress on the hydroxymethylome and opens exciting new avenues of research by highlighting a set of microRNAs that may participate in the prevention or etiology of oxidative-stress-related diseases. Examination of DNA hydroxymethylation landscape in SY5Y cell lines and in intestinal epithelium of mice.
Project description:Integrated-systems model of oxidative stress connecting NRF2 and p53 signaling pathways. Additional crosstalk linking oxidative stress to p53 inhibition, p53 to NRF2 through p21, and NRF2 to MDM2 was incorporated in this model. The NRF2 pathway was encoded as first- and second-order rate equations for KEAP1 oxidation and NRF2 stabilization; NRF2-mediated transcription of antioxidant enzymes was modeled as a Hill function. The p53 pathway was reconstructed from a delay differential equation model of p53 signaling in response to DNA damage. To adapt the p53 DNA-damage model to respond to oxidative stress, we used a first-order oxidation reaction of ATM/CHEK2 by intracellular H2O2.
The integrated base model of NRF2–p53 oxidative-stress signaling contains 42 reactions and 22 ordinary differential equations (ODEs).
Project description:To study whether increase in mitochondrial oxidative stress (SOD2 removal) and decrease in mitochondrial DNA repair (Ogg1 dMTS) results into increase in mitochondrial DNA mutation load. Oxidative stress has been suggested to induce mutations in mtDNA. To verify this, we extracted and sequenced (Illumina) mitochondrial DNA from heart Sod2 knockout animals that were also deficient for mitochondrial base-excision repair. The repair deficiency was induced by removing the genomic region encoding for the predicted mitochondrial targeting sequence from endogenous OGG1 (L2 to W23) called Ogg1 dMTS mice, thus excluding the protein from mitochondria. OGG1 is a DNA glycosylase that recognizes and repairs 8-oxo-dG damage from DNA. Oxidative stress can induce 8-oxo-dG lesions, thus we removed the mitochondrial matrix localized superoxide dismutase (SOD2) from these mice to increase the level of oxidative stress. 8-oxo-dG lesion can be mutagenic because some DNA repair polymerases are known to erroneously incorporate adenosine opposite to 8-oxo-dG during replication leading to GC>TA transversion mutations.
Project description:The experiment aimed to find how Campylobacter responds to oxidative stress using hydrogen peroxide. This was done by using previously made TraDIS libraries (https://bmcmicrobiol.biomedcentral.com/articles/10.1186/s12866-023-02835-8) and putting them under oxidative stress. The strains used were C. jejuni 11168, C. coli 15-537360 and C. coli CCN182.