scholarly journals DNA double-strand breaks induced by reactive oxygen species promote DNA polymerase IV activity inEscherichia coli

2019 ◽  
Author(s):  
Sarah S. Henrikus ◽  
Camille Henry ◽  
John P. McDonald ◽  
Yvonne Hellmich ◽  
Elizabeth A. Wood ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Dna Polymerase ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
Oxygen Species ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Pol Iv ◽  
Dna Polymerase Iv

Under many conditions the killing of bacterial cells by antibiotics is potentiated by DNA damage induced by reactive oxygen species (ROS)1–3. A primary cause of ROS-induced cell death is the accumulation of DNA double-strand breaks (DSBs)1,4–6. DNA polymerase IV (pol IV), an error-prone DNA polymerase produced at elevated levels in cells experiencing DNA damage, has been implicated both in ROS-dependent killing and in DSBR7–15. Here, we show using single-molecule fluorescence microscopy that ROS-induced DSBs promote pol IV activity in two ways. First, exposure to the antibiotics ciprofloxacin and trimethoprim triggers an SOS-mediated increase in intracellular pol IV concentrations that is strongly dependent on both ROS and DSBR. Second, in cells that constitutively express pol IV, treatment with an ROS scavenger dramatically reduces the number of pol IV foci formed upon exposure to antibiotics, indicating a role for pol IV in the repair of ROS-induced DSBs.

BCR/ABL Oncogenic Kinase Promotes Unfaithful Repair of the Reactive Oxygen Species - Dependent DNA Double-Strand Breaks.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 712-712 ◽  
Author(s):  
Tomasz Skorski ◽  
Michal O. Nowicki ◽  
Rafal Falinski ◽  
Mateusz Koptyra ◽  
Artur Slupianek ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Cycle ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Double Strand Breaks ◽  
Transformed Cells ◽  
Oxygen Species ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Abl Kinase

Abstract The oncogenic BCR/ABL tyrosine kinase induces constitutive DNA damage in Philadelphia chromosome (Ph1)-positive leukemia cells. We find that BCR/ABL kinase - induced reactive oxygen species (ROS) cause chronic oxidative DNA damage as indicated by an enzymatic assay detecting oxidized bases. These DNA lesions result in DNA double-strand breaks (DSBs) detected by comet assay, immunofluorescent gamma-H2AX nuclear foci and linker-ligation PCR (LL-PCR). Combined analysis of the length of LL-PCR products and the sequences of two reference genes DR-GFP and Na+/K+ ATPase revealed that ROS dependent DSBs occurred in the regions containing multiple, 5–9bp long stretches of G/C, in concordance with the notion that oxidative DNA damage is predominantly detected in G/C-rich sequences. Elevated numbers of DSBs were detected in BCR/ABL cell lines, murine bone marrow cells transformed with BCR/ABL and in CML patient samples, in comparison to normal counterparts. Inhibition of the BCR/ABL kinase by STI571 and diminishion of ROS activity by the ROS scavenger PDTC reduced DSBs formation. Cell cycle analysis revealed that most of these DSBs occur during S and G2/M phases, and are probably associated with the stalled replication forks. Homologous recombination repair (HRR) and non-homologous end-joining (NHEJ) represent two major mechanisms of DSBs repair in S and G2/M cell cycle phase. Using the in vivo recombination assay consisting of the DSB-dependent reconstitution of the green fluorescent protein (GFP) gene we found that HRR is stimulated in BCR/ABL-positive cells. In addition, in vitro assay measuring the activity of NHEJ revealed that this repair process is also activated by the BCR/ABL kinase. RAD51 and Ku70 play a key role in HRR and NHEJ, respectively. The reaction sites of HRR and NHEJ in the nuclei could be visualized by double-immunofluorescence detecting co-localization of gamma-H2AX foci (DSBs sites) with RAD51 (HRR sites) or Ku70 (NHEJ sites). Equal co-localization frequency of gamma-H2AX foci with RAD51 and Ku70 was detected, suggesting that both HRR and NHEJ play an important role in reparation of ROS-dependent DSBs in BCR/ABL-transformed cells. Analysis of the DSBs repair products in the reporter DR-GFP gene in BCR/ABL cells identified ~40% of HRR and ~60% of NHEJ events. Sequencing revealed point-mutations in HRR products and large deletions in NHEJ products in BCR/ABL-positive cells, but not in non-transformed cells. We propose that the following series of events may contribute to genomic instability of Ph1-positive leukemias: BCR/ABL → ROS → oxidative DNA damage → DSBs in proliferating cells → unfaithful HRR and NHEJ repair. Since BCR/ABL share many similarities with other members of the fusion tyrosine kinases (FTKs) family, these events may contribute to genomic instability of hematological malignancies caused by FTKs.

scholarly journals Through Its Nonstructural Protein NS1, Parvovirus H-1 Induces Apoptosis via Accumulation of Reactive Oxygen Species

2010 ◽  
Vol 84 (12) ◽  
pp. 5909-5922 ◽  
Author(s):  
Georgi Hristov ◽  
Melanie Krämer ◽  
Junwei Li ◽  
Nazim El-Andaloussi ◽  
Rodrigo Mora ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Nonstructural Protein ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
Oxygen Species ◽  
Ns1 Protein ◽  
Dna Double Strand Breaks ◽  
Caspase 9 ◽  
Strand Breaks ◽  
Cycle Arrest

ABSTRACT The rat parvovirus H-1 (H-1PV) attracts high attention as an anticancer agent, because it is not pathogenic for humans and has oncotropic and oncosuppressive properties. The viral nonstructural NS1 protein is thought to mediate H-1PV cytotoxicity, but its exact contribution to this process remains undefined. In this study, we analyzed the effects of the H-1PV NS1 protein on human cell proliferation and cell viability. We show that NS1 expression is sufficient to induce the accumulation of cells in G2 phase, apoptosis via caspase 9 and 3 activation, and cell lysis. Similarly, cells infected with wild-type H-1PV arrest in G2 phase and undergo apoptosis. Furthermore, we also show that both expression of NS1 and H-1PV infection lead to higher levels of intracellular reactive oxygen species (ROS), associated with DNA double-strand breaks. Antioxidant treatment reduces ROS levels and strongly decreases NS1- and virus-induced DNA damage, cell cycle arrest, and apoptosis, indicating that NS1-induced ROS are important mediators of H-1PV cytotoxicity.

scholarly journals Regulation of Reactive Oxygen Species byAtmIs Essential for Proper Response to DNA Double-Strand Breaks in Lymphocytes

2006 ◽  
Vol 178 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Keisuke Ito ◽  
Keiyo Takubo ◽  
Fumio Arai ◽  
Hitoshi Satoh ◽  
Sahoko Matsuoka ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
Oxygen Species ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Proper Response

BCR/ABL oncogenic kinase promotes unfaithful repair of the reactive oxygen species–dependent DNA double-strand breaks

Blood ◽  
2004 ◽  
Vol 104 (12) ◽  
pp. 3746-3753 ◽  
Author(s):  
Michal O. Nowicki ◽  
Rafal Falinski ◽  
Mateusz Koptyra ◽  
Artur Slupianek ◽  
Tomasz Stoklosa ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Philadelphia Chromosome ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
Oxygen Species ◽  
M Cell ◽  
Proliferating Cells ◽  
Strand Breaks

The oncogenic BCR/ABL tyrosine kinase induces constitutive DNA damage in Philadelphia chromosome (Ph)-positive leukemia cells. We find that BCR/ABL-induced reactive oxygen species (ROSs) cause chronic oxidative DNA damage resulting in double-strand breaks (DSBs) in S and G2/M cell cycle phases. These lesions are repaired by BCR/ABL-stimulated homologous recombination repair (HRR) and nonhomologous end-joining (NHEJ) mechanisms. A high mutation rate is detected in HRR products in BCR/ABL-positive cells, but not in the normal counterparts. In addition, large deletions are found in NHEJ products exclusively in BCR/ABL cells. We propose that the following series of events may contribute to genomic instability of Ph-positive leukemias: BCR/ABL → ROSs → oxidative DNA damage → DSBs in proliferating cells → unfaithful HRR and NHEJ repair.

scholarly journals RexAB promotes the survival of Staphylococcus aureus exposed to multiple classes of antibiotics

2021 ◽  
Author(s):  
Rebecca S. Clarke ◽  
Kam Pou Ha ◽  
Andrew M. Edwards
Keyword(s):  
Reactive Oxygen Species ◽  
Staphylococcus Aureus ◽  
Dna Damage ◽  
Sos Response ◽  
Double Strand Breaks ◽  
Oxygen Species ◽  
Bacterial Survival ◽  
Wild Type ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

Antibiotics inhibit essential bacterial processes, resulting in arrest of growth and in some cases cell death. Many antibiotics are also reported to trigger endogenous production of reactive oxygen species (ROS), which damage DNA, leading to induction of the mutagenic SOS response associated with the emergence of drug resistance. However, the type of DNA damage that arises and how this triggers the SOS response is largely unclear. We found that several different classes of antibiotic triggered dose-dependent induction of the SOS response in Staphylococcus aureus , indicative of DNA damage, including some bacteriostatic drugs. The SOS response was heterogenous and varied in magnitude between strains and antibiotics. However, in many cases, full induction of the SOS response was dependent upon the RexAB helicase/nuclease complex, which processes DNA double strand breaks to produce single-stranded DNA and facilitate RecA nucleoprotein filament formation. The importance of RexAB in repair of DNA was confirmed by measuring bacterial survival during antibiotic exposure, with most drugs having significantly greater bactericidal activity against rexB mutants relative to wild type strains. For some, but not all antibiotics there was no difference in bactericidal activity between wild type and rexB mutant under anaerobic conditions, indicative of a role for reactive oxygen species in mediating DNA damage. Taken together, this work confirms previous observations that several classes of antibiotics cause DNA damage in S. aureus and extends them by showing that processing of DNA double strand breaks by RexAB is a major trigger of the mutagenic SOS response and promotes bacterial survival.

scholarly journals In Benign Barrett's Epithelial Cells, Acid Exposure Generates Reactive Oxygen Species That Cause DNA Double-Strand Breaks

2009 ◽  
Vol 69 (23) ◽  
pp. 9083-9089 ◽  
Author(s):  
Hui Ying Zhang ◽  
Kathy Hormi-Carver ◽  
Xi Zhang ◽  
Stuart J. Spechler ◽  
Rhonda F. Souza
Keyword(s):  
Reactive Oxygen Species ◽  
Epithelial Cells ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
Acid Exposure ◽  
Oxygen Species ◽  
Dna Double Strand Breaks ◽  
Strand Breaks

scholarly journals RNA sequencing supports distinct reactive oxygen species-mediated pathways of apoptosis by high and low size mass fractions of Bay leaf (Lauris nobilis) in HT-29 cells

2015 ◽  
Vol 6 (8) ◽  
pp. 2507-2524 ◽  
Author(s):  
Annabelle L. Rodd ◽  
Katherine Ververis ◽  
Dheeshana Sayakkarage ◽  
Abdul W. Khan ◽  
Haloom Rafehi ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Rna Sequencing ◽  
Reactive Oxygen ◽  
Double Strand Breaks ◽  
High Mass ◽  
Oxygen Species ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Mass Fractions ◽  
Ht 29

DNA double strand breaks mediated by high mass bay leaf fraction in HT-29 cells.

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