Evidence of internucleosomal DNA fragmentation and identification of dying cells in X-ray-induced cell death in the developing brain

In this work we have attempted to characterize the programmed cell death process in the chick embryonic interdigital tissue. Interdigital cell death is a prominent phenomenon during limb development and has the role of sculpturing the digits. Morphological changes in the regressing interdigital tissue studied by light, transmission and scanning electron microscopy were correlated with the occurrence of internucleosomal DNA fragmentation, evaluated using agarose gels. Programming of the cell death process was also analyzed by testing the chondrogenic potential of the interdigital mesenchyme, in high density cultures. Our results reveal a progressive loss of the chondrogenic potential of the interdigital mesenchyme, detectable 36 hours before the onset of the degenerative process. Internucleosomal DNA fragmentation was only detected concomitant with the appearance of cells dying with the morphology of apoptosis, but unspecific DNA fragmentation was also present at the same time. This unspecific DNA fragmentation was explained by a precocious activation of the phagocytic removal of the dying cells, confirmed in the tissue sections. From our observations it is suggested that programming of cell death involves changes before endonuclease activation. Further, cell surface changes involved in the phagocytic uptake of the dying cells appear to be as precocious as endonuclease activation.

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Programmed cell death in Drosophila

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1994.0101 ◽

1994 ◽

Vol 345 (1313) ◽

pp. 247-250 ◽

Cited By ~ 16

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Large Fraction ◽

X Ray ◽

Large Numbers ◽

Single Region ◽

Radiation Induced ◽

Induced Apoptosis ◽

Dying Cells ◽

Natural Cell

During Drosophila development, large numbers of cells undergo natural cell death. Even though the onset of these deaths is controlled by many different signals, most of the dying cells undergo common morphological and biochemical changes that are characteristic of apoptosis in vertebrates. We have surveyed a large fraction of the Drosophila genome for genes that are required for programmed cell death by examining the pattern of apoptosis in embryos homozygous for previously identified chromosomal deletions. A single region on the third chromosome (in position 75C1,2) was found to be essential for all cell deaths that normally occur during Drosophila embryogenesis. We have cloned the corresponding genomic DNA and isolated a gene, reaper , which is capable of restoring apoptosis when reintroduced into cell death defective deletions. The reaper gene is specifically expressed in cells that are doomed to die, and its expression precedes the first morphological signs of apoptosis by 1-2 h. This gene is also rapidly induced upon X-ray irradiation, and reaper deletions offer significant protection against radiation-induced apoptosis. Our results suggest that reaper represents a key regulatory switch for the activation of apoptosis in response to a variety of distinct signals.

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Faculty Opinions recommendation of Oxygen causes cell death in the developing brain.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1024084.286703 ◽

2005 ◽

Author(s):

George Perry

Keyword(s):

Cell Death ◽

Developing Brain

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Triggers of Cell Death in the Developing Brain

Current Pediatric Reviews ◽

10.2174/157339611796892292 ◽

2011 ◽

Vol 7 (4) ◽

pp. 293-300 ◽

Cited By ~ 2

Author(s):

Chrysanthy Ikonomidou

Keyword(s):

Cell Death ◽

Developing Brain

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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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TUNEL Assay: A Powerful Tool for Kidney Injury Evaluation

International Journal of Molecular Sciences ◽

10.3390/ijms22010412 ◽

2021 ◽

Vol 22 (1) ◽

pp. 412

Author(s):

Christopher L. Moore ◽

Alena V. Savenka ◽

Alexei G. Basnakian

Keyword(s):

Cell Death ◽

Dna Fragmentation ◽

Cell Injury ◽

Kidney Injury ◽

Cell Types ◽

Tunel Assay ◽

Terminal Deoxynucleotidyl Transferase ◽

Hypoxic Injury ◽

Additional Information ◽

Tissue Compartments

Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay is a long-established assay used to detect cell death-associated DNA fragmentation (3’-OH DNA termini) by endonucleases. Because these enzymes are particularly active in the kidney, TUNEL is widely used to identify and quantify DNA fragmentation and cell death in cultured kidney cells and animal and human kidneys resulting from toxic or hypoxic injury. The early characterization of TUNEL as an apoptotic assay has led to numerous misinterpretations of the mechanisms of kidney cell injury. Nevertheless, TUNEL is becoming increasingly popular for kidney injury assessment because it can be used universally in cultured and tissue cells and for all mechanisms of cell death. Furthermore, it is sensitive, accurate, quantitative, easily linked to particular cells or tissue compartments, and can be combined with immunohistochemistry to allow reliable identification of cell types or likely mechanisms of cell death. Traditionally, TUNEL analysis has been limited to the presence or absence of a TUNEL signal. However, additional information on the mechanism of cell death can be obtained from the analysis of TUNEL patterns.

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Discovery of fungal surface NADases predominantly present in pathogenic species

Nature Communications ◽

10.1038/s41467-021-21307-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Øyvind Strømland ◽

Juha P. Kallio ◽

Annica Pschibul ◽

Renate H. Skoge ◽

Hulda M. Harðardóttir ◽

...

Keyword(s):

Cell Death ◽

Aspergillus Fumigatus ◽

Neurospora Crassa ◽

Binding Site ◽

Host Cell ◽

Nicotinamide Adenine Dinucleotide ◽

Catalytic Mechanism ◽

Pathogenic Species ◽

X Ray ◽

Cellular Bioenergetics

AbstractNicotinamide adenine dinucleotide (NAD) is a key molecule in cellular bioenergetics and signalling. Various bacterial pathogens release NADase enzymes into the host cell that deplete the host’s NAD+ pool, thereby causing rapid cell death. Here, we report the identification of NADases on the surface of fungi such as the pathogen Aspergillus fumigatus and the saprophyte Neurospora crassa. The enzymes harbour a tuberculosis necrotizing toxin (TNT) domain and are predominately present in pathogenic species. The 1.6 Å X-ray structure of the homodimeric A. fumigatus protein reveals unique properties including N-linked glycosylation and a Ca2+-binding site whose occupancy regulates activity. The structure in complex with a substrate analogue suggests a catalytic mechanism that is distinct from those of known NADases, ADP-ribosyl cyclases and transferases. We propose that fungal NADases may convey advantages during interaction with the host or competing microorganisms.

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Lipid peroxidation and the subsequent cell death transmitting from ferroptotic cells to neighboring cells

Cell Death and Disease ◽

10.1038/s41419-021-03613-y ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Hironari Nishizawa ◽

Mitsuyo Matsumoto ◽

Guan Chen ◽

Yusho Ishii ◽

Keisuke Tada ◽

...

Keyword(s):

Lipid Peroxidation ◽

Cell Death ◽

Lipid Peroxide ◽

Nih3t3 Cells ◽

Regulated Cell Death ◽

Primary Mouse ◽

Ischemic Diseases ◽

A Chain ◽

Dying Cells

AbstractFerroptosis is a regulated cell death due to the iron-dependent accumulation of lipid peroxide. Ferroptosis is known to constitute the pathology of ischemic diseases, neurodegenerative diseases, and steatohepatitis and also works as a suppressing mechanism against cancer. However, how ferroptotic cells affect surrounding cells remains elusive. We herein report the transfer phenomenon of lipid peroxidation and cell death from ferroptotic cells to nearby cells that are not exposed to ferroptotic inducers (FINs). While primary mouse embryonic fibroblasts (MEFs) and NIH3T3 cells contained senescence-associated β-galactosidase (SA-β-gal)-positive cells, they were decreased upon induction of ferroptosis with FINs. The SA-β-gal decrease was inhibited by ferroptotic inhibitors and knockdown of Atg7, pointing to the involvement of lipid peroxidation and activated autophagosome formation during ferroptosis. A transfer of cell culture medium of cells treated with FINs, type 1 or 2, caused the reduction in SA-β-gal-positive cells in recipient cells that had not been exposed to FINs. Real-time imaging of Kusabira Orange-marked reporter MEFs cocultured with ferroptotic cells showed the generation of lipid peroxide and deaths of the reporter cells. These results indicate that lipid peroxidation and its aftereffects propagate from ferroptotic cells to surrounding cells, even when the surrounding cells are not exposed to FINs. Ferroptotic cells are not merely dying cells but also work as signal transmitters inducing a chain of further ferroptosis.

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