Antibiotic amoxicillin induces DNA lesions in mammalian cells possibly via the reactive oxygen species

2007 ◽  
Vol 629 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Pei-Yi Li ◽  
Yu-Ching Chang ◽  
Bor-Show Tzang ◽  
Chung-Chu Chen ◽  
Yin-Chang Liu
Keyword(s):  
Reactive Oxygen Species ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Dna Lesions ◽  
Oxygen Species

scholarly journals Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Feng Gao ◽  
Tianyi Shao ◽  
Yunpeng Yu ◽  
Yujie Xiong ◽  
Lihua Yang
Keyword(s):  
Reactive Oxygen Species ◽  
Mammalian Cells ◽  
Bacterial Resistance ◽  
Reactive Oxygen ◽  
Resistant Bacteria ◽  
Oxygen Species ◽  
Antibiotic Resistant ◽  
Generate Surface ◽  
Inert Substrate ◽  
Silver Palladium

AbstractActing by producing reactive oxygen species (ROS) in situ, nanozymes are promising as antimicrobials. ROS’ intrinsic inability to distinguish bacteria from mammalian cells, however, deprives nanozymes of the selectivity necessary for an ideal antimicrobial. Here we report that nanozymes that generate surface-bound ROS selectively kill bacteria over mammalian cells. This result is robust across three distinct nanozymes that universally generate surface-bound ROS, with an oxidase-like silver-palladium bimetallic alloy nanocage, AgPd0.38, being the lead model. The selectivity is attributable to both the surface-bound nature of ROS these nanozymes generate and an unexpected antidote role of endocytosis. Though surface-bound, the ROS on AgPd0.38 efficiently eliminated antibiotic-resistant bacteria and effectively delayed the onset of bacterial resistance emergence. When used as coating additives, AgPd0.38 enabled an inert substrate to inhibit biofilm formation and suppress infection-related immune responses in mouse models. This work opens an avenue toward biocompatible nanozymes and may have implication in our fight against antimicrobial resistance.

Mutagenicity of PFOA in Mammalian Cells: Role of Mitochondria-Dependent Reactive Oxygen Species

2011 ◽  
Vol 45 (4) ◽  
pp. 1638-1644 ◽  
Author(s):  
Guoping Zhao ◽  
Jun Wang ◽  
Xiaofei Wang ◽  
Shaopeng Chen ◽  
Ye Zhao ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Oxygen Species

Activation of the JAK-STAT pathway by reactive oxygen species

1998 ◽  
Vol 275 (6) ◽  
pp. C1640-C1652 ◽  
Author(s):  
Amy R. Simon ◽  
Usha Rai ◽  
Barry L. Fanburg ◽  
Brent H. Cochran
Keyword(s):  
Reactive Oxygen Species ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Buthionine Sulfoximine ◽  
Early Response ◽  
Carcinoma Cells ◽  
Oxygen Species ◽  
Intracellular Ros ◽  
Diphenylene Iodonium ◽  
Stat Pathway

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human diseases, including the acute respiratory distress syndrome, Parkinson’s disease, pulmonary fibrosis, and Alzheimer’s disease. In mammalian cells, several genes known to be induced during the immediate early response to growth factors, including the protooncogenes c- fos and c- myc, have also been shown to be induced by ROS. We show that members of the STAT family of transcription factors, including STAT1 and STAT3, are activated in fibroblasts and A-431 carcinoma cells in response to H2O2. This activation occurs within 5 min, can be inhibited by antioxidants, and does not require protein synthesis. STAT activation in these cell lines is oxidant specific and does not occur in response to superoxide- or nitric oxide-generating stimuli. Buthionine sulfoximine, which depletes intracellular glutathione, also activates the STAT pathway. Moreover, H2O2stimulates the activity of the known STAT kinases JAK2 and TYK2. Activation of STATs by platelet-derived growth factor (PDGF) is significantly inhibited by N-acetyl-l-cysteine and diphenylene iodonium, indicating that ROS production contributes to STAT activation in response to PDGF. These findings indicate that the JAK-STAT pathway responds to intracellular ROS and that PDGF uses ROS as a second messenger to regulate STAT activation.

scholarly journals Ebsulfur Is a Benzisothiazolone Cytocidal Inhibitor Targeting the Trypanothione Reductase of Trypanosoma brucei

2013 ◽  
Vol 288 (38) ◽  
pp. 27456-27468 ◽  
Author(s):  
Jun Lu ◽  
Suman K. Vodnala ◽  
Anna-Lena Gustavsson ◽  
Tomas N. Gustafsson ◽  
Birger Sjöberg ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Trypanosoma Brucei ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Redox System ◽  
Trypanothione Reductase ◽  
Oxygen Species ◽  
African Trypanosomiasis ◽  
Thiol Redox

Trypanosoma brucei is the causing agent of African trypanosomiasis. These parasites possess a unique thiol redox system required for DNA synthesis and defense against oxidative stress. It includes trypanothione and trypanothione reductase (TryR) instead of the thioredoxin and glutaredoxin systems of mammalian hosts. Here, we show that the benzisothiazolone compound ebsulfur (EbS), a sulfur analogue of ebselen, is a potent inhibitor of T. brucei growth with a favorable selectivity index over mammalian cells. EbS inhibited the TryR activity and decreased non-protein thiol levels in cultured parasites. The inhibition of TryR by EbS was irreversible and NADPH-dependent. EbS formed a complex with TryR and caused oxidation and inactivation of the enzyme. EbS was more toxic for T. brucei than for Trypanosoma cruzi, probably due to lower levels of TryR and trypanothione in T. brucei. Furthermore, inhibition of TryR produced high intracellular reactive oxygen species. Hydrogen peroxide, known to be constitutively high in T. brucei, enhanced the EbS inhibition of TryR. The elevation of reactive oxygen species production in parasites caused by EbS induced a programmed cell death. Soluble EbS analogues were synthesized and cured T. brucei brucei infection in mice when used together with nifurtimox. Altogether, EbS and EbS analogues disrupt the trypanothione system, hampering the defense against oxidative stress. Thus, EbS is a promising lead for development of drugs against African trypanosomiasis.

scholarly journals Site-specific targeting of a light activated dCas9-KIllerRed fusion protein generates transient, localized regions of oxidative DNA damage

2020 ◽  
Author(s):  
Nealia C.M. House ◽  
Jacob V. Layer ◽  
Brendan D. Price
Keyword(s):  
Reactive Oxygen Species ◽  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Light Exposure ◽  
Green Light ◽  
Reactive Oxygen ◽  
Dna Lesions ◽  
Oxygen Species ◽  
Dna Breaks ◽  
Site Specific

AbstractDNA repair requires reorganization of the local chromatin structure to facilitate access to and repair of the DNA. Studying DNA double-strand break (DSB) repair in specific chromatin domains has been aided by the use of sequence-specific endonucleases to generate targeted breaks. Here, we describe a new approach that combines KillerRed, a photosensitizer that generates reactive oxygen species (ROS) when exposed to light, and the genome-targeting properties of the CRISPR/Cas9 system. Fusing KillerRed to catalytically inactive Cas9 (dCas9) generates dCas9-KR, which can then be targeted to any desired genomic region with an appropriate guide RNA. Activation of dCas9-KR with green light generates a local increase in reactive oxygen species, resulting in “clustered” oxidative damage, including both DNA breaks and base damage. Activation of dCas9-KR rapidly (within minutes) increases both γH2AX and recruitment of the KU70/80 complex. Importantly, this damage is repaired within 10 minutes of termination of light exposure, indicating that the DNA damage generated by dCas9-KR is both rapid and transient. Further, repair is carried out exclusively through NHEJ, with no detectable contribution from HR-based mechanisms. Surprisingly, sequencing of repaired DNA damage regions did not reveal any increase in either mutations or INDELs in the targeted region, implying that NHEJ has high fidelity under the conditions of low level, limited damage. The dCas9-KR approach for creating targeted damage has significant advantages over the use of endonucleases, since the duration and intensity of DNA damage can be controlled in “real time” by controlling light exposure. In addition, unlike endonucleases that carry out multiple cut-repair cycles, dCas9-KR produces a single burst of damage, more closely resembling the type of damage experienced during acute exposure to reactive oxygen species or environmental toxins. dCas9-KR is a promising system to induce DNA damage and measure site-specific repair kinetics at clustered DNA lesions.

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