scholarly journals Ubiquitin-Dependent Rapid Degradation Conceals A Cell-Protective Function of Cytoplasmic SIRT3 Against Oxidative Stress

2020 ◽  
Author(s):  
Takashi Hayashi ◽  
Takashi Matsushita ◽  
Shin Hisahara ◽  
Naotoshi Iwahara ◽  
Atsushi Kuno ◽  
...  
Keyword(s):  
Cell Death ◽  
Nuclear Translocation ◽  
Neural Precursor ◽  
Neural Cells ◽  
Protective Function ◽  
Lysine Residues ◽  
Dependent Protein ◽  
A Cell ◽  
Protein Deacetylase ◽  
Superoxide Dismutase 2

Abstract SIRT3 is a NAD+-dependent protein deacetylase localized in mitochondria. Although several previous studies reported cytoplasmic and/or nuclear localization of SIRT3, extra-mitochondrial SIRT3 was obscure. We found that mitochondrial (SIRT3mt) and cytoplasmic (SIRT3ct) Sirt3 mRNAs were expressed in the mouse brain and diffuse SIRT3 immunostaining in cytoplasm was detected in cultured neural cells and neural precursor cells where SIRT3 knockdown disturbed neural precursor cell differentiation. However, overexpression of SIRT3 in COS7 cells showed that expression levels of SIRT3ct was much lower than that of SIRT3mt. SIRT3ct but not SIRT3mt was promptly degraded by the ubiquitin-dependent degradation, in which SIRT3ct degradation was mediated mainly by the ubiquitination of NH2-terminal methionine and partly by that of lysine residues. SIRT3ct expression level was significantly enhanced by the treatment of cells with staurosporine or H2O2. H2O2 promoted nuclear translocation of SIRT3ct and induced histone H3 deacetylation and superoxide dismutase 2 expression. The overexpression of SIRT3ct decreased cell death by H2O2 at similar levels achieved by that of SIRT3mt. Knockdown of Sirt3 mRNA increased cell death by amyloid-b (Ab) and the overexpression of SIRT3ct opposed the toxic function of Ab in PC12 cells. These results indicated that SIRT3ct participated in cell survival under various stress conditions.

scholarly journals Zika virus has oncolytic activity against glioblastoma stem cells

2017 ◽  
Vol 214 (10) ◽  
pp. 2843-2857 ◽  
Author(s):  
Zhe Zhu ◽  
Matthew J. Gorman ◽  
Lisa D. McKenzie ◽  
Jiani N. Chai ◽  
Christopher G. Hubert ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Brain Cancer ◽  
Zika Virus ◽  
Oncolytic Virus ◽  
Neural Precursor Cells ◽  
Neural Precursor ◽  
Neural Cells ◽  
Glioblastoma Stem Cells ◽  
Oncolytic Activity

Glioblastoma is a highly lethal brain cancer that frequently recurs in proximity to the original resection cavity. We explored the use of oncolytic virus therapy against glioblastoma with Zika virus (ZIKV), a flavivirus that induces cell death and differentiation of neural precursor cells in the developing fetus. ZIKV preferentially infected and killed glioblastoma stem cells (GSCs) relative to differentiated tumor progeny or normal neuronal cells. The effects against GSCs were not a general property of neurotropic flaviviruses, as West Nile virus indiscriminately killed both tumor and normal neural cells. ZIKV potently depleted patient-derived GSCs grown in culture and in organoids. Moreover, mice with glioblastoma survived substantially longer and at greater rates when the tumor was inoculated with a mouse-adapted strain of ZIKV. Our results suggest that ZIKV is an oncolytic virus that can preferentially target GSCs; thus, genetically modified strains that further optimize safety could have therapeutic efficacy for adult glioblastoma patients.

scholarly journals Computational Analysis of Retrovirus-Inducedscid Cell Death

2001 ◽  
Vol 75 (7) ◽  
pp. 3121-3128 ◽  
Author(s):  
René Daniel ◽  
Samuel Litwin ◽  
Richard A. Katz ◽  
Anna Marie Skalka
Keyword(s):  
Cell Death ◽  
Nonhomologous End Joining ◽  
End Joining ◽  
Dependent Protein Kinase ◽  
Retroviral Infection ◽  
Dna Integration ◽  
Modeling Approach ◽  
Dependent Protein ◽  
A Cell ◽  
Pass Through

ABSTRACT It was shown recently that retroviral infection induces integrase-dependent apoptosis (programmed cell death) in DNA-dependent protein kinase (DNA-PK)-deficient scid pre-B cell lines, and it has been proposed that retroviral DNA integration is perceived as DNA damage that is repairable by the DNA-PK-dependent nonhomologous end-joining pathway (R. Daniel, R. A. Katz, and A. M. Skalka, Science 284:644–647, 1999). Very few infectious virions seem to be necessary to induce scid cell death. In this study, we used a modeling approach to estimate the number of integration events necessary to induce cell death of DNA-PK-deficient scid cells. Several models for integration-mediated cell killing were considered. Our analyses indicate that a single hit (integration event) is sufficient to kill a scid cell. Moreover, the closest fit between the experimental data and our computational simulations was achieved with a model in which the infectedscid cell must pass through S phase to trigger apoptosis. This model is consistent with the findings that a single double-strand DNA break is sufficient to kill a cell deficient in DNA repair and illustrates the potential of a modeling approach to address quantitative aspects of virus-cell interactions.

Nuclear Translocation of Tissue Type Transglutaminase during Sphingosine-Induced Cell Death: A Novel Aspect of the Enzyme with DNA Hydrolytic Activity

1998 ◽  
Vol 53 (5-6) ◽  
pp. 352-358 ◽  
Author(s):  
Yutaka Takeuchi ◽  
Hiroshi Ohashi ◽  
Paul J. Birckbichler ◽  
Takashi Ikejim
Keyword(s):  
Cell Death ◽  
Nuclear Translocation ◽  
Hydrolytic Activity ◽  
Rapid Onset ◽  
Tissue Type ◽  
Cell Nuclei ◽  
Cellular Processes ◽  
A Cell

Abstract Tissue type (type 2) transglutaminase (TGase, EC 2.3.2.13) has been implicated in various cellular processes including cell death. In order to better understand the role of this enzyme in cell death, human melanocytic A375-S2 cells were treated with sphingosine, a cell-signaling mediator. During the rapid onset of cytotoxicity caused by this lipidic agent, tissue TGase was translocated from the cytoplasm to the cell nuclei. This observation was further remarked in relevance to its previously undescribed activity for DNA degradation. The DNA hydrolytic activity associated with tissue TGase was dependent on Mg2+ in contrast to the Ca2+ requirement for the classical cross-linking acrivity of TGase, and was inhibited by Zn2+. Based on the results shown here, we propose a novel aspect of tissue TGase in cell death.

A Cell Death Pathway Induced by Antibody-Mediated Cross-Linking of CD45 on Lymphocytes

2003 ◽  
Vol 23 (5-6) ◽  
pp. 421-440 ◽  
Author(s):  
Ann-Muriel Steff ◽  
Marylene Fortin ◽  
Fabianne Philippoussis ◽  
Sylvie Lesage ◽  
Chantal Arguin ◽  
...  
Keyword(s):  
Cell Death ◽  
Cross Linking ◽  
Cell Death Pathway ◽  
A Cell

scholarly journals ATF3 contributes to brucine-triggered glioma cell ferroptosis via promotion of hydrogen peroxide and iron

2021 ◽  
Author(s):  
Shan Lu ◽  
Xuan-zhong Wang ◽  
Chuan He ◽  
Lei Wang ◽  
Shi-peng Liang ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
Er Stress ◽  
Glioma Cell ◽  
Nuclear Translocation ◽  
Indole Alkaloid ◽  
Ammonium Citrate ◽  
Ferric Ammonium Citrate ◽  
Activating Transcription Factor 3 ◽  
Intracellular Iron

AbstractFerroptotic cell death is characterized by iron-dependent lipid peroxidation that is initiated by ferrous iron and H2O2 via Fenton reaction, in which the role of activating transcription factor 3 (ATF3) remains elusive. Brucine is a weak alkaline indole alkaloid extracted from the seeds of Strychnos nux-vomica, which has shown potent antitumor activity against various tumors, including glioma. In this study, we showed that brucine inhibited glioma cell growth in vitro and in vivo, which was paralleled by nuclear translocation of ATF3, lipid peroxidation, and increases of iron and H2O2. Furthermore, brucine-induced lipid peroxidation was inhibited or exacerbated when intracellular iron was chelated by deferoxamine (500 μM) or improved by ferric ammonium citrate (500 μM). Suppression of lipid peroxidation with lipophilic antioxidants ferrostatin-1 (50 μM) or liproxstatin-1 (30 μM) rescued brucine-induced glioma cell death. Moreover, knockdown of ATF3 prevented brucine-induced accumulation of iron and H2O2 and glioma cell death. We revealed that brucine induced ATF3 upregulation and translocation into nuclei via activation of ER stress. ATF3 promoted brucine-induced H2O2 accumulation via upregulating NOX4 and SOD1 to generate H2O2 on one hand, and downregulating catalase and xCT to prevent H2O2 degradation on the other hand. H2O2 then contributed to brucine-triggered iron increase and transferrin receptor upregulation, as well as lipid peroxidation. This was further verified by treating glioma cells with exogenous H2O2 alone. Moreover, H2O2 reversely exacerbated brucine-induced ER stress. Taken together, ATF3 contributes to brucine-induced glioma cell ferroptosis via increasing H2O2 and iron.

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

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.

scholarly journals Protective Effects of PGC-1α Activators on Ischemic Stroke in a Rat Model of Photochemically Induced Thrombosis

2021 ◽  
Vol 11 (3) ◽  
pp. 325
Author(s):  
Fatima M. Shakova ◽  
Yuliya I. Kirova ◽  
Denis N. Silachev ◽  
Galina A. Romanova ◽  
Sergey G. Morozov
Keyword(s):  
Rat Model ◽  
Nuclear Translocation ◽  
Peroxisome Proliferator ◽  
Protective Effects ◽  
Protein Markers ◽  
Peroxisome Proliferator Activated Receptor ◽  
Pharmacological Agents ◽  
Ischemic Brain ◽  
Neuroprotective Therapy ◽  
Dependent Protein

The pharmacological induction and activation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), a key regulator of ischemic brain tolerance, is a promising direction in neuroprotective therapy. Pharmacological agents with known abilities to modulate cerebral PGC-1α are scarce. This study focused on the potential PGC-1α-modulating activity of Mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) and Semax (ACTH(4–7) analog) in a rat model of photochemical-induced thrombosis (PT) in the prefrontal cortex. Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each. The expression of PGC-1α and PGC-1α-dependent protein markers of mitochondriogenesis, angiogenesis, and synaptogenesis was measured in the penumbra via immunoblotting at Days 1, 3, 7, and 21 after PT. The nuclear content of PGC-1α was measured immunohistochemically. The suppression of PGC-1α expression was observed in the penumbra from 24 h to 21 days following PT and reflected decreases in both the number of neurons and PGC-1α expression in individual neurons. Administration of Mexidol or Semax was associated with preservation of the neuron number and neuronal expression of PGC-1α, stimulation of the nuclear translocation of PGC-1α, and increased contents of protein markers for PGC-1α activation. This study opens new prospects for the pharmacological modulation of PGC-1α in the ischemic brain.

scholarly journals Mitochondria and Pharmacologic Cardiac Conditioning—At the Heart of Ischemic Injury

2021 ◽  
Vol 22 (6) ◽  
pp. 3224
Author(s):  
Christopher Lotz ◽  
Johannes Herrmann ◽  
Quirin Notz ◽  
Patrick Meybohm ◽  
Franz Kehl
Keyword(s):  
Cell Death ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Research Field ◽  
Calcium Handling ◽  
Control Mechanisms ◽  
Intrinsic Resistance ◽  
Atp Production ◽  
Cardiac Conditioning ◽  
A Cell

Pharmacologic cardiac conditioning increases the intrinsic resistance against ischemia and reperfusion (I/R) injury. The cardiac conditioning response is mediated via complex signaling networks. These networks have been an intriguing research field for decades, largely advancing our knowledge on cardiac signaling beyond the conditioning response. The centerpieces of this system are the mitochondria, a dynamic organelle, almost acting as a cell within the cell. Mitochondria comprise a plethora of functions at the crossroads of cell death or survival. These include the maintenance of aerobic ATP production and redox signaling, closely entwined with mitochondrial calcium handling and mitochondrial permeability transition. Moreover, mitochondria host pathways of programmed cell death impact the inflammatory response and contain their own mechanisms of fusion and fission (division). These act as quality control mechanisms in cellular ageing, release of pro-apoptotic factors and mitophagy. Furthermore, recently identified mechanisms of mitochondrial regeneration can increase the capacity for oxidative phosphorylation, decrease oxidative stress and might help to beneficially impact myocardial remodeling, as well as invigorate the heart against subsequent ischemic insults. The current review highlights different pathways and unresolved questions surrounding mitochondria in myocardial I/R injury and pharmacological cardiac conditioning.

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