Dissecting the mechanism of DNA damage induced photoreceptor cell death

Background: Oxidative stress is caused by free radicals or oxidant productions, including lipid peroxidation, protein modification, DNA damage and apoptosis or cell death and results in cellular degeneration and neurodegeneration from damage to macromolecules. Results: Accumulation of the DNA damage (8HOdG) products and the end products of LPO (including aldehyde, diene, triene conjugates and Schiff’s bases) were noted in the research studies. Significantly higher levels of these products in comparison with the controls were observed. Oxidative stress induced changes to ocular cells and tissues. Typical changes include ECM accumulation, cell dysfunction, cell death, advanced senescence, disarrangement or rearrangement of the cytoskeleton and released inflammatory cytokines. It is involved in ocular diseases, including keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, cataract, age-related macular degeneration, primary open-angle glaucoma, retinal light damage, and retinopathy of prematurity. These ocular diseases are the cause of irreversible blindness worldwide. Conclusions: Oxidative stress, inflammation and autophagy are implicated in biochemical and morphological changes in these ocular tissues. The development of therapy is a major target for the management care of these ocular diseases.

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Suppression of FOXM1 Sensitizes Human Cancer Cells to Cell Death Induced by DNA-Damage

PLoS ONE ◽

10.1371/journal.pone.0031761 ◽

2012 ◽

Vol 7 (2) ◽

pp. e31761 ◽

Cited By ~ 47

Author(s):

Marianna Halasi ◽

Andrei L. Gartel

Keyword(s):

Dna Damage ◽

Cell Death ◽

Cancer Cells ◽

Human Cancer ◽

Human Cancer Cells

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Exposure of the cytoplasm to low-dose X-rays modifies ataxia telangiectasia mutated-mediated DNA damage responses

Scientific Reports ◽

10.1038/s41598-021-92213-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Munetoshi Maeda ◽

Masanori Tomita ◽

Mika Maeda ◽

Hideki Matsumoto ◽

Noriko Usami ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Ataxia Telangiectasia ◽

Kinase Inhibitor ◽

Surrogate Marker ◽

X Rays ◽

Ataxia Telangiectasia Mutated ◽

Whole Cell ◽

X Ray ◽

Dna Damage Responses

AbstractWe recently showed that when a low X-ray dose is used, cell death is enhanced in nucleus-irradiated compared with whole-cell-irradiated cells; however, the role of the cytoplasm remains unclear. Here, we show changes in the DNA damage responses with or without X-ray microbeam irradiation of the cytoplasm. Phosphorylated histone H2AX foci, a surrogate marker for DNA double-strand breaks, in V79 and WI-38 cells are not observed in nucleus irradiations at ≤ 2 Gy, whereas they are observed in whole-cell irradiations. Addition of an ataxia telangiectasia mutated (ATM) kinase inhibitor to whole-cell irradiations suppresses foci formation at ≤ 2 Gy. ABL1 and p73 expression is upregulated following nucleus irradiation, suggesting the induction of p73-dependent cell death. Furthermore, CDKN1A (p21) is upregulated following whole-cell irradiation, indicating the induction of cell cycle arrest. These data reveal that cytoplasmic radioresponses modify ATM-mediated DNA damage responses and determine the fate of cells irradiated at low doses.

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SOG1 transcription factor promotes the onset of endoreduplication under salinity stress in Arabidopsis

Scientific Reports ◽

10.1038/s41598-021-91293-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kalyan Mahapatra ◽

Sujit Roy

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Death ◽

Transcription Factor ◽

Programmed Cell Death ◽

Salinity Stress ◽

Crucial Role ◽

Genome Stability ◽

Cell Cycle Checkpoint ◽

Cell Cycle Regulators

AbstractAs like in mammalian system, the DNA damage responsive cell cycle checkpoint functions play crucial role for maintenance of genome stability in plants through repairing of damages in DNA and induction of programmed cell death or endoreduplication by extensive regulation of progression of cell cycle. ATM and ATR (ATAXIA-TELANGIECTASIA-MUTATED and -RAD3-RELATED) function as sensor kinases and play key role in the transmission of DNA damage signals to the downstream components of cell cycle regulatory network. The plant-specific NAC domain family transcription factor SOG1 (SUPPRESSOR OF GAMMA RESPONSE 1) plays crucial role in transducing signals from both ATM and ATR in presence of double strand breaks (DSBs) in the genome and found to play crucial role in the regulation of key genes involved in cell cycle progression, DNA damage repair, endoreduplication and programmed cell death. Here we report that Arabidopsis exposed to high salinity shows generation of oxidative stress induced DSBs along with the concomitant induction of endoreduplication, displaying increased cell size and DNA ploidy level without any change in chromosome number. These responses were significantly prominent in SOG1 overexpression line than wild-type Arabidopsis, while sog1 mutant lines showed much compromised induction of endoreduplication under salinity stress. We have found that both ATM-SOG1 and ATR-SOG1 pathways are involved in the salinity mediated induction of endoreduplication. SOG1was found to promote G2-M phase arrest in Arabidopsis under salinity stress by downregulating the expression of the key cell cycle regulators, including CDKB1;1, CDKB2;1, and CYCB1;1, while upregulating the expression of WEE1 kinase, CCS52A and E2Fa, which act as important regulators for induction of endoreduplication. Our results suggest that Arabidopsis undergoes endoreduplicative cycle in response to salinity induced DSBs, showcasing an adaptive response in plants under salinity stress.

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DNase II mediates a parthanatos-like developmental cell death pathway in Drosophila primordial germ cells

Nature Communications ◽

10.1038/s41467-021-22622-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lama Tarayrah-Ibraheim ◽

Elital Chass Maurice ◽

Guy Hadary ◽

Sharon Ben-Hur ◽

Alina Kolpakova ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Germ Cells ◽

Nuclear Translocation ◽

Primordial Germ Cells ◽

Nuclear Accumulation ◽

Dependent Manner ◽

Dnase Ii ◽

Cell Death Pathway ◽

Parp 1

AbstractDuring Drosophila embryonic development, cell death eliminates 30% of the primordial germ cells (PGCs). Inhibiting apoptosis does not prevent PGC death, suggesting a divergence from the conventional apoptotic program. Here, we demonstrate that PGCs normally activate an intrinsic alternative cell death (ACD) pathway mediated by DNase II release from lysosomes, leading to nuclear translocation and subsequent DNA double-strand breaks (DSBs). DSBs activate the DNA damage-sensing enzyme, Poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) and the ATR/Chk1 branch of the DNA damage response. PARP-1 and DNase II engage in a positive feedback amplification loop mediated by the release of PAR polymers from the nucleus and the nuclear accumulation of DNase II in an AIF- and CypA-dependent manner, ultimately resulting in PGC death. Given the anatomical and molecular similarities with an ACD pathway called parthanatos, these findings reveal a parthanatos-like cell death pathway active during Drosophila development.

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