Ultraviolet irradiation-mediated formation of Aβ42 oligomers and reactive oxygen species in Zn2+-bound Aβ42 aggregates irrespective of the removal of Zn2+

2016 ◽  
Vol 40 (11) ◽  
pp. 9385-9394 ◽  
Author(s):  
Xiang Li ◽  
Xiongwei Dong ◽  
Yaojing Liu ◽  
Yan Meng ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ultraviolet Irradiation ◽  
Uv Light ◽  
Light Exposure ◽  
Reactive Oxygen ◽  
Oxygen Species

The controlled UV light exposure converts redox-inert Zn2+-bound Aβ42 aggregates into cytotoxic Aβ42 oligomers and reactive oxygen species.

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.

scholarly journals Ultraviolet Irradiation-Dependent Fluorescence Enhancement of Hemoglobin Catalyzed by Reactive Oxygen Species

PLoS ONE ◽  
2012 ◽  
Vol 7 (8) ◽  
pp. e44142 ◽  
Author(s):  
Leiting Pan ◽  
Xiaoxu Wang ◽  
Shuying Yang ◽  
Xian Wu ◽  
Imshik Lee ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ultraviolet Irradiation ◽  
Fluorescence Enhancement ◽  
Reactive Oxygen ◽  
Oxygen Species

scholarly journals The influence of light exposure on free radical processes in the lungs of rats with pleurisy

2016 ◽  
Author(s):  
O. M. Larycheva
Keyword(s):  
Reactive Oxygen Species ◽  
Lipid Peroxidation ◽  
Free Radical ◽  
Light Exposure ◽  
Reactive Oxygen ◽  
Male Rats ◽  
Oxygen Species ◽  
Free Radical Processes ◽  
Radical Processes

The experiments on male rats demonstrated that under the conditions of pleurisy induced by carrageenan and short melatonin deficit, a significant increase in the level of reactive oxygen species and products of lipid peroxidation in the lungs takes place.

Photoactivation of core–shell titania coated upconversion nanoparticles and their effect on cell death

2014 ◽  
Vol 2 (40) ◽  
pp. 7017-7026 ◽  
Author(s):  
Niagara Muhammad Idris ◽  
Sasidharan Swarnalatha Lucky ◽  
Zhengquan Li ◽  
Kai Huang ◽  
Yong Zhang
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Uv Light ◽  
Reactive Oxygen ◽  
Upconversion Nanoparticles ◽  
Core Shell ◽  
Oxygen Species

Titania-coated upconversion nanoparticles convert 980 nm to UV light for activation of coated titania to generate reactive oxygen species against cells.

scholarly journals Cytotoxic responses to 405nm light exposure in mammalian and bacterial cells: Involvement of reactive oxygen species

2016 ◽  
Vol 33 ◽  
pp. 54-62 ◽  
Author(s):  
Praveen Ramakrishnan ◽  
Michelle Maclean ◽  
Scott J. MacGregor ◽  
John G. Anderson ◽  
M. Helen Grant
Keyword(s):  
Reactive Oxygen Species ◽  
Light Exposure ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Cytotoxic Responses

scholarly journals Pyrolytic formation and photoactivity of reactive oxygen species in a SiO2/carbon nanocomposite from kraft lignin

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1574 ◽  
Author(s):  
Dhanalakshmi Vadivel ◽  
Ilanchelian Malaichamy
Keyword(s):  
Reactive Oxygen Species ◽  
Uv Light ◽  
Atmospheric Oxygen ◽  
Reactive Oxygen ◽  
Kraft Lignin ◽  
Peroxyl Radicals ◽  
Ros Generation ◽  
Oxygen Species ◽  
Oxygenated Functional Groups ◽  
Carbon Nanocomposite

SiO2 and carbon produced by kraft lignin pyrolyzed at 600°C can generate stable reactive oxygen species (ROS) by reaction with atmospheric oxygen. In this study, we systematically investigate the photochemistry of peroxyl radicals in carbon-supported silica (PCS) and assess its effects on the methylene blue (MB) photodegradation. Characterization revealed that the higher ROS generation ability of SiO2/carbon under UV light irradiation was attributed to its abundant photoactive surface-oxygenated functional groups.

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