The antioxidant network acts as a firewall in maintenance of genomic integrity
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo Sapiens
SUBMITTER: 
Xiang Li
PROVIDER: PXD071844 | iProX | Wed Dec 10 00:00:00 GMT 2025
REPOSITORIES: iProX
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Project description:Faithful genome integrity maintenance plays an essential role in cell survival. Here, we identify the RNA demethylase ALKBH5 as a key regulator that protects cells from DNA damage and apoptosis during reactive oxygen species (ROS)-induced stress. We find that ROS significantly induces global mRNA N6-methyladenosine (m6A) levels by modulating ALKBH5 post-translational modifications (PTMs), leading to the rapid and efficient induction of thousands of genes involved in a variety of biological processes including DNA damage repair. Mechanistically, ROS promotes ALKBH5 SUMOylation through activating ERK/JNK signaling, leading to inhibition of ALKBH5 m6A demethylase activity by blocking substrate accessibility. Moreover, ERK/JNK/ALKBH5-PTMs/m6A axis is activated by ROS in hematopoietic stem/progenitor cells (HSPCs) in vivo in mice, suggesting a physiological role of this molecular pathway in the maintenance of genome stability in HSPCs. Together, our study uncovers a molecular mechanism involving ALKBH5 PTMs and increased mRNA m6A levels that protect genomic integrity of cells in response to ROS.
2021-04-29 | GSE144620 | GEO
Project description:Introduction: Ischemia/reperfusion injury (IRI) is a common damage due to the restoration of blood flow after an ischemic insult. The pathogenesis of IRI is mainly linked to the production of ROS which sustain cell damage and ultimately promote cell death. The tardigrade damage suppressor protein (Dsup) is a DNA-binding protein that enables tardigrades to tolerate stress conditions including oxidative stress. Aim: We aim to investigate the ability of the tardigrade-derived Damage Suppressor (Dsup) protein to protect human cells from IRI, using an in vitro model of hypoxia and reoxygenation. Methods: The protective role of the tardigrade Dsup protein against ischemia-reperfusion injury was studied in transfected HEK293T cells. We analyzed cell viability, oxidative stress, and the expression of antioxidant proteins using functional assays, proteomics, and Western Blotting. Results: Dsup expression significantly enhanced cell survival following hypoxia-reoxygenation and markedly reduced intracellular ROS levels. Proteomic and Western Blot analyses revealed a significant upregulation of antioxidant enzymes in Dsup-expressing cells. Furthermore, Dsup modulated autophagy and key stress-related pathways, including the MAPK cascade. Dsup remained cytoplasmic under all conditions, and its expression was notably increased by hypoxic stimulus. Conclusion: This study demonstrate that Dsup protects human cells from ischemia-reperfusion injury by reducing oxidative stress and modulating key cytoprotective pathways. Our results establish Dsup as a promising candidate for future therapeutic applications against IRI, meriting further exploration in in vivo models.
2025-11-24 | PXD067125 | Pride
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).
2021-10-29 | MODEL2110270001 | BioModels
Project description:Reactive oxygen species (ROS) are extensively assessed in physiological and pathological studies; however, the genes and mechanisms involved in antioxidant reactions are elusive. To address this knowledge gap, we used a forward genetic approach with mouse haploid embryonic stem cells (haESCs) to generate high-throughput mutant libraries, from which numerous oxidative stress-targeting genes were screened out. We performed proof-of-concept experiments to validate the potential inserted genes. Slc25a43 (one of the candidates) knockout (KO) ESCs presented reduced damage caused by ROS and higher cell viability when exposed to H2O2. Subsequently, ROS production and mitochondrial function analysis also confirmed that Slc25a43 was a main target gene of oxidative toxicity. In addition, we identified that KO of Slc25a43 activated mitochondria-related genes including Nlrx1 to protect ESCs from oxidative damage. Overall, our findings facilitated revealing target genes of oxidative stress and shed lights on the mechanism underlying oxidative death.
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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
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Project description:Nutrient deprivation triggers the release of signal-sequence-lacking antioxidant superoxide dismutase 1 (SOD1). We now report that secreted SOD1 is functionally active and accompanied by export of other antioxidant enzymes such as thioredoxins, (Trx1 and Trx2) and peroxiredoxin Ahp1. Our data reveal that starvation increases mitochondrial activity, which generates higher, but non-toxic, levels of reactive oxygen species (ROS). Inhibiting mitochondrial activity or ROS prevents antioxidants secretion. We suggest that in response to ROS production that can permeate the plasma membrane, the cells respond by secreting antioxidants to prevent ROS-mediated damage in the extracellular space. These findings provide an understanding of why cells secrete signal sequence lacking antioxidant enzymes in response to starvation.
2020-03-26 | PXD016815 | Pride
Project description:Human fungal pathogens must survive diverse reactive oxygen species (ROS) produced by host immune cells. ROS can oxidize a range of cellular molecules including proteins, lipids, and DNA. Formation of lipid radicals by ROS can be especially damaging, as it leads to a chain reaction of lipid peroxidation that causes widespread damage to the plasma membrane. Most previous studies on antioxidant pathways in fungal pathogens have been conducted with hydrogen peroxide, so the pathways used to combat organic peroxides and lipid peroxidation are not well understood. The most well-known peroxidase in Candida albicans, catalase, only acts on hydrogen peroxide. We therefore characterized a family of four glutathione peroxidases (GPxs) that were predicted to play an important role in reducing organic peroxides. One of the GPxs, Gpx3 is also known to activate the Cap1 transcription factor that plays the major role in inducing antioxidant genes in response to ROS. Surprisingly, we found that the only measurable role of the GPxs is activation of Cap1 and did not find a significant role for GPxs in the direct detoxification of peroxides. Furthermore, a CAP1 deletion mutant strain was highly sensitive to organic peroxides and oxidized lipids, indicating an important role for antioxidant genes upregulated by Cap1 in protecting cells from organic peroxides. We identified GLR1 (Glutathione reductase), a gene upregulated by Cap1, as important for protecting cells from oxidized lipids, implicating glutathione utilizing enzymes in the protection against lipid peroxidation. Furthermore, an RNA-sequencing study in C. albicans measuring the transcriptional response for exposure to an organic peroxide showed upregulation of antioxidant and protein damage pathways. Overall, our results identify novel mechanisms by which C. albicans responds to oxidative stress resistance which open new avenues for understanding how fungal pathogens resist ROS in the host.
2024-09-20 | GSE275502 | GEO
Project description:Aims: Vascular wall resident stem cells (SCs) hold great promise for cardiovascular regenerative therapy. This study evaluated the impact of oxidative stress on the viability and functionality of saphenous vein'derived pericytes (SVPs), SVPs'deriv ed cells and terminally differentiated vascular cells. We also investigated the molecular mechanisms underlying the SVP resistance to oxidative stress. Results: SVPs exhibit a significantly higher resistance to oxidative stress resulting in reduced apoptosis upon exposure to hydrogen peroxide in comparison to endothelial cells (ECs). This was attributed to upregulation of genes encoding for anti'oxidant enzymes, especially superoxide dismutases (SODs) and catalase. Pharmacological inhibition of SODs increased ROS levels in SVPs and impaired their survival. Furthermore, we confirm that, when exposed to differentiation stimuli, SVPs are able to generate mesodermic lineages. Interestingly, differentiation of SVPs resulted in SOD down'regulation and increased apoptosis upon exposure to hydrogen peroxide. Oxidative stress caused an incremental increase on SVPs migration, whilst being inhibitory for the ECs. Additionally, oxidative stress did not impair SVPs capacity to promote angiogenesis in vitro. Innovations: This study for the first time demonstrates that SCs resident in veins of cardiovascular patients are endowed with enhanced detoxifier and antioxidant system. Conclusions: SVPs expanded from vein remnants of coronary artery bypass graft surgery express antioxidant defense mechanisms which allow them resist to high levels of ROS. These properties highlight the potential of SVPs in cardiovascular regenerative medicine. 2 groups 3 replicates
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Project description:Sedanolide is a bioactive compound with anti-inflammatory and antitumor activities. Although it has been recently suggested that sedanolide activates the nuclear factor E2-related factor 2 (NRF2) pathway, there is little research on its effects on cellular resistance to oxidative stress. The objective of the present study was to investigate the function of sedanolide in suppressing hydrogen peroxide (H2O2)-induced oxidative damage and the underlying molecular mechanisms in human hepatoblastoma cell line HepG2 cells. We found that sedanolide activated the antioxidant response element (ARE)-dependent transcription mediated by the nuclear translocation of NRF2. Pathway enrichment analysis of RNA sequencing data revealed that sedanolide upregulated the transcription of antioxidant enzymes involved in the NRF2 pathway and glutathione metabolism. Then, we further investigated whether sedanolide exerts cytoprotective effects against H2O2-induced cell death. We showed that sedanolide significantly attenuated cytosolic and mitochondrial reactive oxygen species (ROS) generation induced by exposure to H2O2. Furthermore, we demonstrated that pretreatment with sedanolide conferred a significant cytoprotective effect against H2O2-induced cell death by preventing the decrease of the mitochondrial membrane potential and the increase of caspase-3/7 activity. Our study demonstrated that sedanolide enhanced cellular resistance to oxidative damage via the activation of the Keich-like ECH-associated protein 1 (KEAP1)–NRF2 pathway.
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