Hydrogen peroxide induces a specific DNA base change profile in the presence of the iron chelator 2,2’ dipyridyl in Escherichia coli

Felício, D.L.; Almeida, Carlos Eduardo Bonacossa de; Silva, A.B.; Leitão, Álvaro C.

doi:10.1590/s0100-879x2009007500001

Cited by 2 publications

(1 citation statement)

References 23 publications

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“…No significant differences in Sytox Green accessibility was detected between cells isolated from treated cultures and untreated cultures when stationary phase ETEC cultures incubated for 3 h at 37 • C in the presence or absence of up to 20 mM hydrogen peroxide, revealing intact membranes (Supplementary Figure 2). We note that this concentration of hydrogen peroxide is higher than typically used in reports of oxidative stress in laboratory (K12) strains of E. coli, and that higher concentrations (up to 50 mM) of hydrogen peroxide are usually necessary to induce stress in studies of pathogenic E. coli (Bearson et al, 2009;Felicio et al, 2009;Łoś et al, 2010;Mei et al, 2017). To validate that our treatment conditions nevertheless did result in oxidation of ETEC proteins, we analyzed whole cell extracts and observed an increase in oxidative carbonyl modifications (Supplementary Figure 3).…”

Section: Isolation and Proteomic Analysis Of Omvs Produced After Oxidative Stressmentioning

confidence: 85%

Differential Packaging Into Outer Membrane Vesicles Upon Oxidative Stress Reveals a General Mechanism for Cargo Selectivity

Orench‐Rivera

Kuehn

2021

Front. Microbiol.

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Selective cargo packaging into bacterial extracellular vesicles has been reported and implicated in many biological processes, however, the mechanism behind the selectivity has remained largely unexplored. In this study, proteomic analysis of outer membrane (OM) and OM vesicle (OMV) fractions from enterotoxigenic E. coli revealed significant differences in protein abundance in the OMV and OM fractions for cultures shifted to oxidative stress conditions. Analysis of sequences of proteins preferentially packaged into OMVs showed that proteins with oxidizable residues were more packaged into OMVs in comparison with those retained in the membrane. In addition, the results indicated two distinct classes of OM-associated proteins were differentially packaged into OMVs as a function of peroxide treatment. Implementing a Bayesian hierarchical model, OM lipoproteins were determined to be preferentially exported during stress whereas integral OM proteins were preferentially retained in the cell. Selectivity was determined to be independent of transcriptional regulation of the proteins upon oxidative stress and was validated using randomly selected protein candidates from the different cargo classes. Based on these data, a hypothetical functional and mechanistic basis for cargo selectivity was tested using OmpA constructs. Our study reveals a basic mechanism for cargo selectivity into OMVs that may be useful for the engineering of OMVs for future biotechnological applications.

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Section: Isolation and Proteomic Analysis Of Omvs Produced After Oxidative Stressmentioning

confidence: 85%

Differential Packaging Into Outer Membrane Vesicles Upon Oxidative Stress Reveals a General Mechanism for Cargo Selectivity

Orench‐Rivera

Kuehn

2021

Front. Microbiol.

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Virus-Like Cytosolic and Cell-Free Oxidatively Damaged Nucleic Acids Likely Drive Inflammation, Synapse Degeneration, and Neuron Death in Alzheimer’s Disease

Sanders

2023

ADR

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Oxidative stress, inflammation, and amyloid-β are Alzheimer’s disease (AD) hallmarks that cause each other and other AD hallmarks. Most amyloid-β-lowering, antioxidant, anti-inflammatory, and antimicrobial AD clinical trials failed; none stopped or reversed AD. Although signs suggest an infectious etiology, no pathogen accumulated consistently in AD patients. Neuropathology, neuronal cell culture, rodent, genome-wide association, epidemiological, biomarker, and clinical studies, plus analysis using Hill causality criteria and revised Koch’s postulates, indicate that the virus-like oxidative damage-associated molecular-pattern (DAMP) cytosolic and cell-free nucleic acids accumulated in AD patients’ brains likely drive neuroinflammation, synaptotoxicity, and neurotoxicity. Cytosolic oxidatively-damaged mitochondrial DNA accumulated outside mitochondria dose-dependently in preclinical AD and AD patients’ hippocampal neurons, and in AD patients’ neocortical neurons but not cerebellar neurons or glia. In oxidatively-stressed neural cells and rodents’ brains, cytosolic oxidatively-damaged mitochondrial DNA accumulated and increased antiviral and inflammatory proteins, including cleaved caspase-1, interleukin-1β, and interferon-β. Cytosolic double-stranded RNA and DNA are DAMPs that induce antiviral interferons and/or inflammatory proteins by oligomerizing with various innate-immune pattern-recognition receptors, e.g., cyclic GMP-AMP synthase and the nucleotide-binding-oligomerization-domain-like-receptor-pyrin-domain-containing-3 inflammasome. In oxidatively-stressed neural cells, cytosolic oxidatively-damaged mitochondrial DNA caused synaptotoxicity and neurotoxicity. Depleting mitochondrial DNA prevented these effects. Additionally, cell-free nucleic acids accumulated in AD patients’ blood, extracellular vesicles, and senile plaques. Injecting cell-free nucleic acids bound to albumin oligomers into wild-type mice’s hippocampi triggered antiviral interferon-β secretion; interferon-β injection caused synapse degeneration. Deoxyribonuclease-I treatment appeared to improve a severe-AD patient’s Mini-Mental Status Exam by 15 points. Preclinical and clinical studies of deoxyribonuclease-I and a ribonuclease for AD should be prioritized.

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Hydrogen peroxide induces a specific DNA base change profile in the presence of the iron chelator 2,2’ dipyridyl in Escherichia coli

Cited by 2 publications

References 23 publications

Differential Packaging Into Outer Membrane Vesicles Upon Oxidative Stress Reveals a General Mechanism for Cargo Selectivity

Differential Packaging Into Outer Membrane Vesicles Upon Oxidative Stress Reveals a General Mechanism for Cargo Selectivity

Virus-Like Cytosolic and Cell-Free Oxidatively Damaged Nucleic Acids Likely Drive Inflammation, Synapse Degeneration, and Neuron Death in Alzheimer’s Disease

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