scholarly journals An Atlas of Phosphorylation and Proteolytic Processing Events During Excitotoxic Neuronal Death Reveals New Therapeutic Opportunities

2020 ◽  
Author(s):  
S. Sadia Ameen ◽  
Antoine Dufour ◽  
M. Iqbal Hossain ◽  
Ashfaqul Hoque ◽  
Sharelle Sturgeon ◽  
...  
Keyword(s):  
Cell Death ◽  
Protein Kinases ◽  
Neuronal Death ◽  
Neurological Disorders ◽  
Protein Modification ◽  
Neuronal Loss ◽  
Axonal Guidance ◽  
Death Process ◽  
Molecular Events

SummaryExcitotoxicity, a neuronal death process in neurological disorders, is initiated by over-stimulation of neuronal ionotropic glutamate receptors. The over-stimulated receptors dysregulate proteases, protein kinases and phosphatases, which in turn modify target neuronal proteins to induce cell death. To decipher this cell death mechanism, we used quantitative proteomics, phosphoproteomics and N-terminomics to identify modified proteins in excitotoxic neurons. Data, available in ProteomeXchange (identifiers: PXD019527 and PXD019211), enabled us to identify over one thousand such proteins with calpains, cathepsins and over twenty protein kinases as their major modifiers. These protein modification events can potentially perturb signalling pathways governing cell survival, synaptogenesis, axonal guidance and mRNA processing. Importantly, blocking the modification of Src protein kinase, a signalling hub in excitotoxic neurons, protected against neuronal loss in vivo in a rat model of neurotoxicity. Besides offering new insights into excitotoxic neuronal death mechanism, our findings suggest potential neuroprotective therapeutic targets for treating neurological disorders.Graphical abstractHighlightsMulti-dimensional proteomic analysis identified proteins modified by proteolysis and altered phosphorylation in neurons undergoing excitotoxic cell death.Calpains, cathepsins and over twenty protein kinases are major modifiers of these proteins.These protein modification events are predicted to impact cell survival, axonal guidance, synaptogenesis and mRNA processing.Blocking modification of an identified protein Src, which acts as a major signalling hub in neurons, was protective against excitotoxic injury in vivo.In BriefUsing multidimensional proteomic approaches, Ameen, et al. mapped the changes of proteome, phosphoproteome and N-terminome of cultured primary neurons during excitotoxicity, a crucial neuronal death process in neurological disorders. These proteomic changes document new excitotoxicity-associated molecular events, and offer insights into how these events are organized to induce neuronal death. Potential therapeutic relevance of these molecular events is illustrated by the demonstration that in vivo blockade of one of these events could protect against excitotoxic neuronal loss.

scholarly journals APR-246 induces early cell death by ferroptosis in acute myeloid leukemia.

Haematologica ◽  
2021 ◽  
Author(s):  
Rudy Birsen ◽  
Clement Larrue ◽  
Justine Decroocq ◽  
Natacha Johnson ◽  
Nathan Guiraud ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Ex Vivo ◽  
Lipid Peroxides ◽  
Death Process ◽  
Glutathione Biosynthesis ◽  
Acute Myeloid

APR-246 is a promising new therapeutic agent that targets p53 mutated proteins in myelodysplastic syndromes and in acute myeloid leukemia. APR-246 reactivates the transcriptional activity of p53 mutants by facilitating their binding to DNA target sites. Recent studies in solid cancers have found that APR-246 can also induce p53-independent cell death. In this study, we demonstrate that AML cell death occurring early after APR-246 exposure is suppressed by iron chelators, lipophilic antioxidants and inhibitors of lipid peroxidation, and correlates with the accumulation of markers of lipid peroxidation, thus fulfilling the definition of ferroptosis, a recently described cell death process. The capacity of AML cells to detoxify lipid peroxides by increasing their cystine uptake to maintain major antioxidant molecule glutathione biosynthesis after exposure to APR-246 may be a key determinant of sensitivity to this compound. The association of APR-246 with induction of ferroptosis (either by pharmacological compounds, or genetic inactivation of SLC7A11 or GPX4) had a synergistic effect on the promotion of cell death, both in vivo and ex vivo.

scholarly journals Overexpression of Mitochondrial Calcium Uniporter Causes Neuronal Death

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Veronica Granatiero ◽  
Marco Pacifici ◽  
Anna Raffaello ◽  
Diego De Stefani ◽  
Rosario Rizzuto
Keyword(s):  
Cell Fate ◽  
Neuronal Death ◽  
Cortical Neurons ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Neuronal Loss ◽  
Calcium Uniporter ◽  
Organelle Morphology

Neurodegenerative diseases are a large and heterogeneous group of disorders characterized by selective and progressive death of specific neuronal subtypes. In most of the cases, the pathophysiology is still poorly understood, although a number of hypotheses have been proposed. Among these, dysregulation of Ca2+ homeostasis and mitochondrial dysfunction represent two broadly recognized early events associated with neurodegeneration. However, a direct link between these two hypotheses can be drawn. Mitochondria actively participate to global Ca2+ signaling, and increases of [Ca2+] inside organelle matrix are known to sustain energy production to modulate apoptosis and remodel cytosolic Ca2+ waves. Most importantly, while mitochondrial Ca2+ overload has been proposed as the no-return signal, triggering apoptotic or necrotic neuronal death, until now direct evidences supporting this hypothesis, especially in vivo, are limited. Here, we took advantage of the identification of the mitochondrial Ca2+ uniporter (MCU) and tested whether mitochondrial Ca2+ signaling controls neuronal cell fate. We overexpressed MCU both in vitro, in mouse primary cortical neurons, and in vivo, through stereotaxic injection of MCU-coding adenoviral particles in the brain cortex. We first measured mitochondrial Ca2+ uptake using quantitative genetically encoded Ca2+ probes, and we observed that the overexpression of MCU causes a dramatic increase of mitochondrial Ca2+ uptake both at resting and after membrane depolarization. MCU-mediated mitochondrial Ca2+ overload causes alteration of organelle morphology and dysregulation of global Ca2+ homeostasis. Most importantly, MCU overexpression in vivo is sufficient to trigger gliosis and neuronal loss. Overall, we demonstrated that mitochondrial Ca2+ overload is per se sufficient to cause neuronal cell death both in vitro and in vivo, thus highlighting a potential key step in neurodegeneration.

scholarly journals Iron toxicity, lipid peroxidation and ferroptosis after intracerebral haemorrhage

2019 ◽  
Vol 4 (2) ◽  
pp. 93-95 ◽  
Author(s):  
Jieru Wan ◽  
Honglei Ren ◽  
Jian Wang
Keyword(s):  
Lipid Peroxidation ◽  
Cell Death ◽  
Intracerebral Haemorrhage ◽  
Neuronal Death ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Iron Toxicity ◽  
Secondary Brain Injury

Intracerebral haemorrhage (ICH) is a devastating type of stroke with high mortality and morbidity. However, we have few options for ICH therapy and limited knowledge about post-ICH neuronal death and related mechanisms. In the aftermath of ICH, iron overload within the perihaematomal region can induce lethal reactive oxygen species (ROS) production and lipid peroxidation, which contribute to secondary brain injury. Indeed, iron chelation therapy has shown efficacy in preclinical ICH studies. Recently, an iron-dependent form of non-apoptotic cell death known as ferroptosis was identified. It is characterised by an accumulation of iron-induced lipid ROS, which leads to intracellular oxidative stress. The ROS cause damage to nucleic acids, proteins and lipid membranes, and eventually cell death. Recently, we and others discovered that ferroptosis does occur after haemorrhagic stroke in vitro and in vivo and contributes to neuronal death. Inhibition of ferroptosis is beneficial in several in vivo and in vitro ICH conditions. This minireview summarises current research on iron toxicity, lipid peroxidation and ferroptosis in the pathomechanisms of ICH, the underlying molecular mechanisms of ferroptosis and the potential for combined therapeutic strategies. Understanding the role of ferroptosis after ICH will provide a vital foundation for cell death-based ICH treatment and prevention.

RelB silencing to reverse tamoxifen resistance by regulating GPx4 and ferroptosis in breast cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e12513-e12513
Author(s):  
Zhi Xu ◽  
Jinhai Tang
Keyword(s):  
Breast Cancer ◽  
Lipid Peroxidation ◽  
Cell Death ◽  
Cell Lines ◽  
Apoptotic Cell ◽  
Morphological Changes ◽  
Death Process ◽  
Enhancer Element ◽  
High Level

e12513 Background: Tamoxifen(Tam), as an essential therapeutic treatment of estrogen receptor(ER)-positive breast cancer(BCa), has been available for the past three decades. However, the induction of Tam resistance during therapy has indicated a significant challenge with regards to this agent. Tam could increase oxidative stress and induce cell death by regulating reactive oxygen species(ROS). Ferroptosis, a cell death process driven by the accumulation of iron-dependent lipid peroxides, has been induced by inactivation/depletion of glutathione peroxidases(GPxs). Our previous studies found that the expression level of RelB gene, a member of NF-κB family, is negatively correlated with ER targeted by Tam in BCa. Methods: The RelB level of BCa tumor tissues and the corresponding cell lines were examined by immunoblotting and western blot. The effects of Tam on cell viability were determined using colony survival and MTT assay. The ROS and oxygen consumption rates(OCR) were measured using specific ROS detection probes and a Seahorse XF96 Analyzer, respectively. The lipid peroxidation level of cells was analyzed by immunofluorescence assay. The morphological changes of mitochondria were observed by transmission electron microscope. RelB binding to the NF-κB intronic enhancer region of the human GPx4 gene was determined using a ChIP assay. Accordingly, the effect of RelB on BCa Tam resistance was further validated using BCa mice xenograft models. Results: RelB was uniquely expressed at the high level in Tam resistance BCa tissues and cell lines. Down-regulation of RelB based on a CRISPR/Cas9 system remarkably sensitized resistance BCa cells to Tam. Treatment with SN52, a RelB inhibitor, illuminated the role of RelB in Tam-treated BCa cells. The high level of ROS and declination of mitochondrial respiration which induced by Tam were inhibited in resistance cells. Tam enhanced lipid peroxidation with concomitant non-apoptotic cell death, which are negatively regulated by GPx4 activity. In addition to GPx4 knockdown, deferoxamine was able to rescue Tam-induced cell death in BCa cells, verifying that Tam induces cell death partially through ferroptosis. Importantly, RelB upregulates GPx4 expression through binding to an NF-κB enhancer element located at the 5’-flanking region. Consistently, in vivo functional validation confirmed that RelB inhibition not only impairs tumor growth, but also inhibits Tam resistance in nude mice. Conclusions: RelB could inhibit ferroptosis which induced by hydroxyl radicals accumulation through upregulating GPx4 in BCa.

Erratum to “Molecular events involved in neuronal death induced in the mouse hippocampus by in vivo injection of kainic acid” [Mol. Brain Res. 93 (2001) 190–198]

2003 ◽  
Vol 119 (2) ◽  
pp. 220
Author(s):  
Myriam Djebaı&#x;li ◽  
Mireille Lerner-Natoli ◽  
Pascale Montpied ◽  
Valérie Baille ◽  
Joël Bockaert ◽  
...  
Keyword(s):  
Kainic Acid ◽  
Neuronal Death ◽  
Molecular Events ◽  
Mouse Hippocampus

Molecular events involved in neuronal death induced in the mouse hippocampus by in-vivo injection of kainic acid

2001 ◽  
Vol 93 (2) ◽  
pp. 190-198 ◽  
Author(s):  
Myriam Djebaı̈li ◽  
Mireille Lerner-Natoli ◽  
Montpied Pascale ◽  
Valérie Baille ◽  
Joël Bockaert ◽  
...  
Keyword(s):  
Kainic Acid ◽  
Neuronal Death ◽  
Molecular Events ◽  
Mouse Hippocampus

Programmed cell death with a necrotic-like phenotype

2013 ◽  
Vol 4 (3) ◽  
pp. 259-275 ◽  
Author(s):  
Michael J. Morgan ◽  
Zheng-gang Liu
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Mammalian Development ◽  
Programmed Necrosis ◽  
Physiological Processes ◽  
Molecular Events ◽  
Regulated Necrosis

AbstractProgrammed cell death is the process by which an individual cell in a multicellular organism commits cellular ‘suicide’ to provide a long-term benefit to the organism. Thus, programmed cell death is important for physiological processes such as development, cellular homeostasis, and immunity. Importantly, in this process, the cell is not eliminated in response to random events but in response to an intricate and genetically defined set of internal cellular molecular events or ‘program’. Although the apoptotic process is generally very well understood, programmed cell death that occurs with a necrotic-like phenotype has been much less studied, and it is only within the past few years that the necrotic program has begun to be elucidated. Originally, programmed necrosis was somewhat dismissed as a nonphysiological phenomenon that occurs in vitro. Recent in vivo studies, however, suggest that regulated necrosis is an authentic classification of cell death that is important in mammalian development and other physiological processes, and programmed necrosis is now considered a significant therapeutic target in major pathological processes as well. Although the RIP1-RIP3-dependent necrosome complex is recognized as being essential for the execution of many instances of programmed necrosis, other downstream and related necrotic molecules and pathways are now being characterized. One of the current challenges is understanding how and under what conditions these pathways are linked together.

scholarly journals Neuroprotective Effects of the Anti-cancer Drug Lapatinib Against Epileptic Seizures via Suppressing Glutathione Peroxidase 4-Dependent Ferroptosis

2020 ◽  
Vol 11 ◽  
Author(s):  
Ji-Ning Jia ◽  
Xi-Xi Yin ◽  
Qin Li ◽  
Qi-Wen Guan ◽  
Nan Yang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Glutathione Peroxidase ◽  
Neuronal Death ◽  
Epileptic Seizures ◽  
Death Process ◽  
Cancer Drug ◽  
Neuroprotective Effects ◽  
Anti Cancer ◽  
Lapatinib Treatment

Epilepsy is a complex neurological disorder characterized by recurrent and unprovoked seizures. Neuronal death process is implicated in the development of repetitive epileptic seizures. Therefore, cell death can be harnessed for ceasing seizures and epileptogenesis. Oxidative stress is regarded as a contributing factor of neuronal death activation and there is compelling evidence supporting antioxidants hold promise in abrogating seizure-related cell modality. Lapatinib, a well-known anti-cancer drug, has been traditionally reported to exert anti-tumor effect via modulating oxidative stress and a recent work illustrates the improvement of encephalomyelitis in rodent models after lapatinib treatment. However, whether lapatinib is beneficial for inhibiting neuronal death and epileptic seizure remains unknown. Here, we found that lapatinib remarkably prevented kainic acid (KA)-epileptic seizures in mice and ferroptosis, a newly defined cell death which is associated with oxidative stress, was involved in the neuroprotection of lapatinib. In the ferroptotic cell death model, lapatinib exerted neuroprotection via restoring glutathione peroxidase 4 (GPX4). Treatment with GPX4 inhibitor ras-selective lethal small molecule 3 (RSL3) abrogated its anti-ferroptotic potential. In a mouse model of KA-triggered seizure, it was also validated that lapatinib blocked GPX4-dependent ferroptosis. It is concluded that lapatinib has neuroprotective potential against epileptic seizures via suppressing GPX4-mediated ferroptosis.

scholarly journals Role of P2X7 Receptors in Ischemic and Excitotoxic Brain Injury In Vivo

2003 ◽  
Vol 23 (3) ◽  
pp. 381-384 ◽  
Author(s):  
Rosalind A. Le Feuvre ◽  
David Brough ◽  
Omar Touzani ◽  
Nancy J. Rothwell
Keyword(s):  
Cell Death ◽  
Cerebral Ischemia ◽  
Neuronal Death ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
P2x7 Receptors ◽  
Excitotoxic Cell Death ◽  
Experimentally Induced

Purinergic P2X7 receptors may affect neuronal cell death through their ability to regulate the processing and release of interleukin-1β (IL-1β), a key mediator in neurodegeneration. The authors tested the hypothesis that ATP, acting at P2X7 receptors, contributes to experimentally induced neuronal death in rodents in vivo. Deletion of P2X7 receptors (P2X7 knockout mice) did not affect cell death induced by temporary cerebral ischemia, which was reduced by treatment with IL-1 receptor antagonist (IL-1RA). Treatment of mice with P2X antagonists did not affect ischemic or excitotoxic cell death, suggesting that P2X7 receptors are not primary mediators of experimentally induced neuronal death.

scholarly journals Inhibition of microRNA-181 Reduces Forebrain Ischemia-Induced Neuronal Loss

2013 ◽  
Vol 33 (12) ◽  
pp. 1976-1982 ◽  
Author(s):  
Jeong-mi Moon ◽  
Lijun Xu ◽  
Rona G Giffard
Keyword(s):  
Cell Death ◽  
Neuronal Survival ◽  
Infarct Volume ◽  
Glutamate Transporter ◽  
Neuronal Loss ◽  
Male Rats ◽  
Global Cerebral Ischemia ◽  
Forebrain Ischemia

MicroRNA (miRNA), miR-181a, is enriched in the brain, and inhibition of miR-181a reduced astrocyte death in vitro and infarct volume after stroke in vivo. This study investigated the role of miR-181a in neuronal injury in vitro and hippocampal neuronal loss in vivo after forebrain ischemia. miR-181a levels were altered by transfection with mimic or antagomir. N2a cells subjected to serum deprivation and oxidative stress showed less cell death when miR-181a was reduced and increased death when miR-181a increased; protection was associated with increased Bcl-2 protein. In contrast, transfected primary neurons did not show altered levels of cell death when miR-181a levels changed. Naive male rats and rats stereotactically infused with miR-181a antagomir or control were subjected to forebrain ischemia and cornus ammonis (CA)1 neuronal survival and protein levels were assessed. Forebrain ischemia increased miR-181a expression and decreased Bcl-2 protein in the hippocampal CA1 region. miR-181a antagomir reduced miR-181a levels, reduced CA1 neuronal loss, increased Bcl-2 protein, and significantly prevented the decrease of glutamate transporter 1. Thus, miR-181a antagomir reduced evidence of astrocyte dysfunction and increased CA1 neuronal survival. miR-181a inhibition is thus a potential target in the setting of forebrain or global cerebral ischemia as well as focal ischemia.

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