scholarly journals Fusion of lysosomes to plasma membrane initiates radiation-induced apoptosis

2020 ◽  
Vol 219 (4) ◽  
Author(s):  
Charles S. Ferranti ◽  
Jin Cheng ◽  
Chris Thompson ◽  
Jianjun Zhang ◽  
Jimmy A. Rotolo ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Ionizing Radiation ◽  
Plasma Membranes ◽  
Calcium Influx ◽  
Acid Sphingomyelinase ◽  
Oxygen Species ◽  
Physical Damage ◽  
Biophysical Mechanism ◽  
Radiation Induced ◽  
Induced Apoptosis

Diverse stresses, including reactive oxygen species (ROS), ionizing radiation, and chemotherapies, activate acid sphingomyelinase (ASMase) and generate the second messenger ceramide at plasma membranes, triggering apoptosis in specific cells, such as hematopoietic cells and endothelium. Ceramide elevation drives local bilayer reorganization into ceramide-rich platforms, macrodomains (0.5–5-µm diameter) that transmit apoptotic signals. An unresolved issue is how ASMase residing within lysosomes is released extracellularly within seconds to hydrolyze sphingomyelin preferentially enriched in outer plasma membranes. Here we show that physical damage by ionizing radiation and ROS induces full-thickness membrane disruption that allows local calcium influx, membrane lysosome fusion, and ASMase release. Further, electron microscopy reveals that plasma membrane “nanopore-like” structures (∼100-nm diameter) form rapidly due to lipid peroxidation, allowing calcium entry to initiate lysosome fusion. We posit that the extent of upstream damage to mammalian plasma membranes, calibrated by severity of nanopore-mediated local calcium influx for lysosome fusion, represents a biophysical mechanism for cell death induction.

Granulocyte-Macrophage Colony-Stimulating Factor Rescues TF-1 Leukemia Cells From Ionizing Radiation-Induced Apoptosis Through a Pathway Mediated by Protein Kinase Cα

Blood ◽  
1998 ◽  
Vol 92 (2) ◽  
pp. 416-424 ◽  
Author(s):  
Mary L. Kelly ◽  
Yan Tang ◽  
Nitsa Rosensweig ◽  
Sanda Clejan ◽  
Barbara S. Beckman
Keyword(s):  
Protein Kinase ◽  
Ionizing Radiation ◽  
Colony Stimulating Factor ◽  
Gm Csf ◽  
Pkc Isoforms ◽  
Radiation Induced ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Induced Apoptosis ◽  
Stimulating Factor

Abstract Protein kinase C (PKC) activity has a recognized role in mediating apoptosis. However, the role of individual PKC isoforms in apoptosis is poorly defined. Therefore, we investigated the translocation of individual PKC isoforms during radiation-induced apoptosis with and without rescue from apoptosis by granulocyte-macrophage colony-stimulating factor (GM-CSF) in the human erythroleukemia cell line TF-1. PKCα was translocated from the particulate to cytosolic fraction of TF-1 cells within 5 minutes of treatment with apoptosis-inducing levels of ionizing radiation. However, this postirradiation translocation did not occur when cells were rescued from apoptosis by GM-CSF. Furthermore, treatment of cells with Gö6976, an inhibitor of classical PKC isoforms, abrogated the rescue effect of GM-CSF. The calcium-independent novel PKC isoform, PKCδ appeared to be degraded in both the particulate and cytosolic fractions of TF-1 cells after treatment with apoptosis-inducing levels of ionizing radiation in either the presence or absence of GM-CSF rescue. Levels of ceramide, a lipid mediator of apoptosis, were measured at 2, 4, 8, 10, and 60 minutes after treatment with ionizing radiation and were substantially reduced in TF-1 cells rescued from apoptosis by GM-CSF compared with apoptotic TF-1 cells. The largest decrease in ceramide production seen was at 4 minutes postirradiation, with a 46% reduction in ceramide levels in TF-1 cells rescued from apoptosis by GM-CSF compared with those in apoptotic TF-1 cells. Because ceramide has been shown to affect PKCα subcellular distribution, these data implicate a role for ceramide in mediating the rapid postirradiation translocation and inhibition of PKCα in TF-1 cells not rescued from apoptosis by GM-CSF. Expression of the antiapoptotic protein Bcl-2 doubled in TF-1 cells rescued from apoptosis by GM-CSF, but did not increase in unrescued cells. Our findings suggest that activated PKCα and increased expression of Bcl-2 after γ irradiation determine survival in TF-1 cells rescued from apoptosis with GM-CSF and that PKCδ plays a role in mediating signals involved in sensing cellular damage and/or regulation of cell damage repair.

scholarly journals Catalase Inhibits Ionizing Radiation-Induced Apoptosis in Hematopoietic Stem and Progenitor Cells

2015 ◽  
Vol 24 (11) ◽  
pp. 1342-1351 ◽  
Author(s):  
Xia Xiao ◽  
Hongmei Luo ◽  
Kenneth N. Vanek ◽  
Amanda C. LaRue ◽  
Bradley A. Schulte ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Progenitor Cells ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells ◽  
Radiation Induced ◽  
Induced Apoptosis

Flavonoids, the Family of Plant-derived Antioxidants making inroads into Novel Therapeutic Design against IR-induced Oxidative Stress in Parkinson’s Disease

2021 ◽  
Vol 19 ◽  
Author(s):  
Tapan Behl ◽  
Gagandeep Kaur ◽  
Aayush Sehgal ◽  
Gokhan Zengin ◽  
Sukhbir Singh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Ionizing Radiation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Radiation Induced ◽  
Novel Therapeutic

Background: Ionizing radiation from telluric sources is unceasingly an unprotected pitfall to humans. Thus, the foremost contributors to human exposure are global and medical radiations. Various pieces of evidences assembled during preceding years reveal the pertinent role of ionizing radiation-induced oxidative stress in the progression of neurodegenerative insults such as Parkinson’s disease, which have been contributing to increased proliferation and generation of reactive oxygen species. Objective: This review delineates the role of ionizing radiation-induced oxidative stress in Parkinson’s disease and proposes novel therapeutic interventions of flavonoid family offering effective management and slowing down the progression of Parkinson’s disease. Method: Published papers were searched via MEDLINE, PubMed, etc. published to date for in-depth database collection. Results: The potential of oxidative damage may harm the non-targeted cells. It can also modulate the functions of central nervous system, such as protein misfolding, mitochondria dysfunction, increased levels of oxidized lipids, and dopaminergic cell death, which accelerates the progression of Parkinson’s disease at the molecular, cellular, or tissue levels. In Parkinson’s disease, reactive oxygen species exacerbate the production of nitric oxides and superoxides by activated microglia, rendering death of dopaminergic neuronal cell through different mechanisms. Conclusion: Rising interest has extensively engrossed on the clinical trial designs based on the plant derived family of antioxidants. They are known to exert multifarious impact either way in neuroprotection via directly suppressing ionizing radiation-induced oxidative stress and reactive oxygen species production or indirectly increasing the dopamine levels and activating the glial cells.

scholarly journals Involvement of reactive oxygen species in ionizing radiation–induced upregulation of cell surface Toll-like receptor 2 and 4 expression in human monocytic cells

2017 ◽  
Vol 58 (5) ◽  
pp. 626-635 ◽  
Author(s):  
Hironori Yoshino ◽  
Ikuo Kashiwakura
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Synthesis ◽  
Ionizing Radiation ◽  
Cell Surface ◽  
Reactive Oxygen ◽  
Mitogen Activated Protein Kinase ◽  
Protein Synthesis Inhibitor ◽  
Oxygen Species ◽  
X Ray ◽  
Radiation Induced

Abstract Toll-like receptors (TLRs) are pattern recognition receptors that recognize pathogen-associated molecular patterns and are indispensable for antibacterial and antiviral immunity. Our previous report showed that ionizing radiation increases the cell surface expressions of TLR2 and TLR4 and enhances their responses to agonists in human monocytic THP1 cells. The present study investigated how ionizing radiation increases the cell surface expressions of TLR2 and TLR4 in THP1 cells. The THP1 cells treated or not treated with pharmaceutical agents such as cycloheximide and N-acetyl-L-cysteine (NAC) were exposed to X-ray irradiation, following which the expressions of TLRs and mitogen-activated protein kinase were analyzed. X-ray irradiation increased the mRNA expressions of TLR2 and TLR4, and treatment with a protein synthesis inhibitor cycloheximide abolished the radiation-induced upregulation of their cell surface expressions. These results indicate that radiation increased those receptors through de novo protein synthesis. Furthermore, treatment with an antioxidant NAC suppressed not only the radiation-induced upregulation of cell surface expressions of TLR2 and TLR4, but also the radiation-induced activation of the c-Jun N-terminal kinase (JNK) pathway. Since it has been shown that the inhibitor for JNK can suppress the radiation-induced upregulation of TLR expression, the present results suggest that ionizing radiation increased the cell surface expressions of TLR2 and TLR4 through reactive oxygen species–mediated JNK activation.

Ionizing radiation stimulates muscarinic regulation of rat intestinal mucosal function

1998 ◽  
Vol 275 (6) ◽  
pp. G1333-G1340 ◽  
Author(s):  
F. Lebrun ◽  
A. Francois ◽  
M. Vergnet ◽  
L. Lebaron-Jacobs ◽  
P. Gourmelon ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Enzyme Activities ◽  
Plasma Membranes ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Marker Enzyme ◽  
Γ Irradiation ◽  
Ussing Chambers ◽  
Radiation Induced ◽  
Total Body

The aim of this study was to determine whether ionizing radiation modifies muscarinic regulation of intestinal mucosal function. Rats exposed to total body 8-Gy γ-irradiation or sham irradiated were studied up to 21 days after irradiation. Basal and carbachol-stimulated short-circuit current ( I sc) and transepithelial conductance ( G t) of stripped ileum were determined in Ussing chambers. Muscarinic receptor characteristics using the muscarinic antagonist [3H]quinuclidinyl benzilate and three unlabeled antagonists were measured in small intestinal plasma membranes together with two marker enzyme activities (sucrase, Na+-K+-ATPase). Enzyme activities were decreased 4 days after irradiation ( day 4). Basal electrical parameters were unchanged. Maximal carbachol-induced changes in I sc and G t were increased at day 4 (maximal Δ I sc = 195.8 ± 14.7 μA/cm2, n = 19, vs. 115.4 ± 8.2 μA/cm2, n = 63, for control rats) and unchanged at day 7. Dissociation constant was decreased at day 4 (0.73 ± 0.29 nM, n = 10, vs. 2.14 ± 0.39 nM, n = 13, for control rats) but unchanged at day 7, without change in binding site number. Thus total body irradiation induces a temporary stimulation of cholinergic regulation of mucosal intestinal function that may result in radiation-induced diarrhea.

PS-341–mediated selective targeting of multiple myeloma cells by synergistic increase in ionizing radiation-induced apoptosis

2005 ◽  
Vol 33 (7) ◽  
pp. 784-795 ◽  
Author(s):  
Apollina Goel ◽  
Angela Dispenzieri ◽  
Philip R. Greipp ◽  
Thomas E. Witzig ◽  
Ruben A. Mesa ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Ionizing Radiation ◽  
Myeloma Cells ◽  
Selective Targeting ◽  
Radiation Induced ◽  
Induced Apoptosis ◽  
Synergistic Increase

Modification of radiation-induced apoptosis in radiation- or hyperthermia-adapted human lymphocytes

1994 ◽  
Vol 72 (11-12) ◽  
pp. 475-482 ◽  
Author(s):  
S. P. Cregan ◽  
D. R. Boreham ◽  
P. R. Walker ◽  
D. L. Brown ◽  
R. E. J. Mitchel
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Adaptive Response ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Fluorescence Analysis ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Protective Mechanism ◽  
Radiation Induced ◽  
Induced Apoptosis

We have investigated the influence of the cellular adaptive response to ionizing radiation on radiation-induced apoptosis in human cells. The adaptive response is believed to be a protective mechanism that confers resistance to the detrimental effects of ionizing radiation and that can be induced by different agents, including hyperthermia and radiation. We have used fluorescence analysis of DNA unwinding (FADU) to assay the induction of apoptosis in human peripheral blood lymphocytes by ionizing radiation. Using the FADU assay, we have observed the initial radiation-induced DNA damage, its subsequent disappearance due to enzymatic repair, and its time- and dose-dependent reappearance. We believe this reappearance of DNA damage to be indicative of the DNA fragmentation event associated with apoptosis. This interpretation has been supported at the individual cell level using an in situ terminal deoxynucleotidyl transferase (TDT) assay (Apoptag, Oncor Inc.), which detects the 3′-hydroxyl ends of fragmented DNA, and by fluorescence analysis of nuclear morphology in Hoechst 33258 stained cells. Pretreatment of cells with low-dose γ-radiation (0.1 Gy) or mild hyperthermia (40 °C for 30 min) altered the extent of radiation-induced (3 Gy) apoptosis. Both pretreatments sensitized lymphocytes to become apoptotic after the 3-Gy radiation exposure. This sensitization may represent an adaptive response mechanism that reduces the risk that genetically damaged cells will proliferate. The ability to modify the probability of radiation-induced apoptosis may lower the cancer risk from a radiation exposure.Key words: apoptosis, adaptive response, ionizing radiation, hyperthermia.

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