scholarly journals Calcineurin-mediated Bad translocation regulates cyanide-induced neuronal apoptosis

2004 ◽  
Vol 379 (3) ◽  
pp. 805-813 ◽  
Author(s):  
Yan SHOU ◽  
Li LI ◽  
Krishnan PRABHAKARAN ◽  
Joseph L. BOROWITZ ◽  
Gary E. ISOM
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Cyclosporin A ◽  
Apoptotic Cell ◽  
Calcineurin Inhibitors ◽  
Apoptotic Response ◽  
Cytochrome C Release ◽  
Cortical Cells ◽  
Subsequent Activation ◽  
Induced Apoptosis

In cyanide-induced apoptosis, an increase in cytosolic free Ca2+ and generation of reactive oxygen species are initiation stimuli for apoptotic cell death. Previous studies have shown that cyanide-stimulated translocation of Bax (Bcl-associated X protein) to mitochondria is linked with release of cytochrome c and subsequent activation of a caspase cascade [Shou, Li, Prabhakaran, Borowitz and Isom (2003) Toxicol. Sci. 75, 99–107]. In the present study, the relationship of the cyanide-induced increase in cytosolic free Ca2+ to activation of Bad (Bcl-2/Bcl-XL-antagonist, causing cell death) was determined in cortical cells. Bad is a Ca2+-sensitive pro-apoptotic Bcl-2 protein, which on activation translocates from cytosol to mitochondria to initiate cytochrome c release. In cultured primary cortical cells, cyanide produced a concentration- and time-dependent translocation of Bad from cytosol to mitochondria. Translocation occurred early in the apoptotic response, since mitochondrial Bad was detected within 1 h of cyanide treatment. Mitochondrial levels of the protein continued to increase up to 12 h post-cyanide exposure. Concurrent with Bad translocation, a Ca2+-sensitive increase in cellular calcineurin activity was observed. Increased cytosolic Ca2+ and calcineurin activation stimulated Bad translocation since BAPTA [bis-(o-aminophenoxy)ethane-N,N,N´,N´-tetra-acetic acid], an intracellular Ca2+ chelator, and cyclosporin A, a calcineurin inhibitor, significantly reduced translocation. BAPTA also blocked release of cytochrome c from mitochondria as well as apoptosis. Furthermore, treatment of cells with the calcineurin inhibitors cyclosporin A or FK506 blocked the apoptotic response, linking calcineurin activation and the subsequent translocation of Bad to cell death. These observations show that by inducing a rapid increase in cytosolic free Ca2+, cyanide can partially initiate the apoptotic cascade through a calcineurin-mediated translocation of Bad to mitochondria.

scholarly journals Contribution of Mitochondrial Ion Channels to Chemo-Resistance in Cancer Cells

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 761 ◽  
Author(s):  
Roberta Peruzzo ◽  
Ildiko Szabo
Keyword(s):  
Ion Channels ◽  
Cytochrome C ◽  
Cancer Cells ◽  
Cytochrome C Release ◽  
Drug Induced ◽  
Point Of No Return ◽  
Different Types ◽  
Subsequent Activation ◽  
Induced Apoptosis ◽  
Potential Efficiency

Mitochondrial ion channels are emerging oncological targets, as modulation of these ion-transporting proteins may impact on mitochondrial membrane potential, efficiency of oxidative phosphorylation and reactive oxygen production. In turn, these factors affect the release of cytochrome c, which is the point of no return during mitochondrial apoptosis. Many of the currently used chemotherapeutics induce programmed cell death causing damage to DNA and subsequent activation of p53-dependent pathways that finally leads to cytochrome c release from the mitochondrial inter-membrane space. The view is emerging, as summarized in the present review, that ion channels located in this organelle may account in several cases for the resistance that cancer cells can develop against classical chemotherapeutics, by preventing drug-induced apoptosis. Thus, pharmacological modulation of these channel activities might be beneficial to fight chemo-resistance of different types of cancer cells.

scholarly journals VANILLIN EXTRACTED FROM PROSO MILLET AND BARNYARD MILLET INDUCE APOPTOSIS IN HT-29 AND MCF-7 CELL LINE THROUGH MITOCHONDRIA MEDIATED PATHWAY

2017 ◽  
Vol 10 (12) ◽  
pp. 226 ◽  
Author(s):  
Deepa Priya Ramadoss ◽  
Nageswaran Sivalingam
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Barnyard Millet ◽  
Proso Millet ◽  
Ht 29 ◽  
Mcf 7

Objective: The main aim of the study was to investigate the bioactive compound vanillin extracted from proso millet (compound 1), and barnyard millet (compound 2) induces apoptotic cell death and whether it is mediated through mitochondrial pathway in HT-29 and MCF-7 cell line.Methods: The cells were treated with 250 μg/ml and 1000 μg/ml concentration of extracted vanillin for 48 hrs. Cytochrome c release and expression level of pro-apoptotic protein Bax and caspase-9 were detected by western blot analysis.Results: The results reveal that extracted compounds increased the release of cytochrome c and upregulating the expression of Bax and caspase-9 as concentration increases in a dose-dependent manner.Conclusion: The study suggests that the vanillin compound extracted from these millets induces apoptotic cell death through a mitochondria-dependent pathway.

scholarly journals Cleavage of Mcd1 by Caspase-like Protease Esp1 Promotes Apoptosis in Budding Yeast

2008 ◽  
Vol 19 (5) ◽  
pp. 2127-2134 ◽  
Author(s):  
Hui Yang ◽  
Qun Ren ◽  
Zhaojie Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Apoptotic Cell ◽  
Model System ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Dual Functions

Over the last decade, yeast has been used successfully as a model system for studying the molecular mechanism of apoptotic cell death. Here, we report that Mcd1, the yeast homology of human cohesin Rad21, plays an important role in hydrogen peroxide-induced apoptosis in yeast. On induction of cell death, Mcd1 is cleaved and the C-terminal fragment is translocated from nucleus into mitochondria, causing the decrease of mitochondrial membrane potential and the amplification of cell death in a cytochrome c-dependent manner. We further demonstrate that the caspase-like protease Esp1 has dual functions and that it is responsible for the cleavage of Mcd1 during the hydrogen peroxide-induced apoptosis. When apoptosis is induced, Esp1 is released from the anaphase inhibitor Pds1. The activated Esp1 acts as caspase-like protease for the cleavage of Mcd1, which enhances the cell death via its translocation from nucleus to mitochondria.

Caspase-dependent cytochrome c release and cell death in chick cardiomyocytes after simulated ischemia-reperfusion

2004 ◽  
Vol 286 (6) ◽  
pp. H2280-H2286 ◽  
Author(s):  
Yimin Qin ◽  
Terry L. Vanden Hoek ◽  
Kim Wojcik ◽  
Travis Anderson ◽  
Chang-Qing Li ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Ischemia Reperfusion ◽  
Caspase 8 ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Simulated Ischemia ◽  
Baseline Levels ◽  
Caspase 2 ◽  
Induced Apoptosis

We recently demonstrated that reperfusion rapidly induces the mitochondrial pathway of apoptosis in chick cardiomyocytes after 1 h of simulated ischemia. Here we tested whether ischemia-reperfusion (I/R)-induced apoptosis could be initiated by caspase-dependent cytochrome c release in this model of cardiomyocyte injury. Fluorometric assays of caspase activity showed little, if any, activation of caspases above baseline levels induced by 1 h of ischemia alone. However, these assays revealed rapid activation of caspase-2, yielding a 2.95 ± 0.52-fold increase (over ischemia only) within the 1st h of reperfusion, whereas activities of caspases-3, -8, and -9 increased only slightly from their baseline levels. The rapid and prominent activation of caspase-2 suggested that it could be an important initiator caspase in this model, and using specific caspase inhibitors given only at the point of reperfusion, we tested this hypothesis. The caspase-2 inhibitor benzyloxycarbonyl-Val-Asp(Ome)-Val-Ala-Asp(Ome)-CH2F was the only caspase inhibitor that significantly inhibited cytochrome c release from mitochondria. This inhibitor also completely blocked activation of caspases-3, -8, and -9. The caspase-3/7 inhibitor transiently and only partially blocked caspase-2 activity and was less effective in blocking the activities of caspases-8 and -9. The caspase-8 inhibitor failed to significantly block caspase-2 or -3, and the caspase-9 inhibitor blocked only caspase-9. Furthermore, the caspase-2 inhibitor protected against I/R-induced cell death, but the caspase-8 inhibitor failed to do so. These data suggest that active caspase-2 initiates cytochrome c release after reperfusion and that it is critical for the I/R-induced apoptosis in this model.

Mechanisms of p53-dependent apoptosis

2001 ◽  
Vol 29 (6) ◽  
pp. 684-688 ◽  
Author(s):  
M. Schuler ◽  
D. R. Green
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
Mitochondrial Outer Membrane ◽  
Caspase Activation ◽  
Caspase 9 ◽  
High Molecular Weight Complex ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Cellular Stresses ◽  
Induced Apoptosis

Cellular stresses, such as growth factor deprivation, DNA damage or oncogene expression, lead to stabilization and activation of the p53 tumour suppressor protein. Depending on the cellular context, this results in one of two different outcomes: cell cycle arrest or apoptotic cell death. Cell death induced through the p53 pathway is executed by the caspase proteinases, which, by cleaving their substrates, lead to the characteristic apoptotic phenotype. Caspase activation by p53 occurs through the release of apoptogenic factors from the mitochondria, including cytochrome c and Smac/DIABLO. Released cytochrome c allows the formation of a high-molecular weight complex, the apoptosome, which consists of the adapter protein Apaf-1 and caspase 9, which is activated following recruitment into the apoptosome. Active caspase 9 then cleaves and activates the effector caspases, such as caspases-3 and -7, which execute the death program. Released Smac/DIABLO facilitates caspase activation through repression of the IAP caspase inhibitor proteins. The release of mitochondrial apoptogenic factors is regulated by the pro- and anti-apoptotic Bcl-2 family proteins, which either induce or prevent the permeabilization of the outer mitochondrial membrane. The mechanism by which p53 signals to the Bcl-2 family proteins is unclear. It was shown that some of the pro-apoptotic family members, such as Bax, Noxa or PUMA, are transcriptional targets of p53. In addition, transcription-independent, pro-apoptotic activities of p53 have been described. The elucidation of the p53-dependent pathway, resulting in mitochondrial outer membrane permeabilization through the pro-apoptotic Bcl-2 family proteins, is a key to unveiling the mechanism of stress-induced apoptosis.

scholarly journals Ligands of the Mitochondrial 18 kDa Translocator Protein Attenuate Apoptosis of Human Glioblastoma Cells Exposed to Erucylphosphohomocholine

2008 ◽  
Vol 30 (5) ◽  
pp. 435-450
Author(s):  
Wilfried Kugler ◽  
Leo Veenman ◽  
Yulia Shandalov ◽  
Svetlana Leschiner ◽  
Ilana Spanier ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Cytochrome C ◽  
Cyclosporin A ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Translocator Protein ◽  
Glioblastoma Cells ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Induced Apoptosis

Background: We have previously shown that the anti-neoplastic agent erucylphosphohomocholine (ErPC3) requires the mitochondrial 18 kDa Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor (PBR), to induce cell death via the mitochondrial apoptosis pathway.Methods: With the aid of the dye JC-1 and cyclosporin A, applied to glioblastoma cells, we now investigated the significance of opening of the mitochondrial permeability transition pore (MPTP) for ErPC3-induced apoptosis in interaction with the TSPO ligands, PK 11195 and Ro5 4864. Furthermore, we measured cytochrome c release, and caspase-9 and -3 activation in this paradigm.Results: The human glioblastoma cell lines, U87MG, A172 and U118MG express the MPTP-associated TSPO, voltage-dependent anion channel and adenine nucleotide transporter. Indeed, ErPC3-induced apoptosis was inhibited by the MPTP blocker cyclosporin A and by PK 11195 and Ro5 4864 in a concentration-dependent manner. Furthermore, PK 11195 and Ro5 4864 inhibited collapse of the mitochondrial membrane potential, cytochrome c release, and caspase-9 and -3 activation caused by ErPC3 treatment.Conclusions: This study shows that PK 11195 and Ro5 4864 inhibit the pro-apoptotic function of ErPC3 by blocking its capacity to cause a collapse of the mitochondrial membrane potential. Thus, the TSPO may serve to open the MPTP in response to anti-cancer drugs such as ErPC3.

scholarly journals Alternating metabolic pathways in NGF-deprived sympathetic neurons affect caspase-independent death

2003 ◽  
Vol 162 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Louis K. Chang ◽  
Robert E. Schmidt ◽  
Eugene M. Johnson
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
Sympathetic Neurons ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Minor Role ◽  
Caspase Inhibitor ◽  
Cytochrome C Release ◽  
Independent Manner

Mitochondrial release of cytochrome c in apoptotic cells activates caspases, which execute apoptotic cell death. However, the events themselves that culminate in caspase activation can have deleterious effects because caspase inhibitor–saved cells ultimately die in a caspase-independent manner. To determine what events may underlie this form of cell death, we examined bioenergetic changes in sympathetic neurons deprived of NGF in the presence of a broad-spectrum caspase inhibitor, boc-aspartyl-(OMe)-fluoromethylketone. Here, we report that NGF-deprived, boc-aspartyl-(OMe)-fluoromethylketone–saved neurons rely heavily on glycolysis for ATP generation and for survival. Second, the activity of F0F1 contributes to caspase-independent death, but has only a minor role in the maintenance of mitochondrial membrane potential, which is maintained primarily by electron transport. Third, permeability transition pore inhibition by cyclosporin A attenuates NGF deprivation–induced loss of mitochondrial proteins, suggesting that permeability transition pore opening may have a function in regulating the degradation of mitochondria after cytochrome c release. Identification of changes in caspase inhibitor–saved cells may provide the basis for rational strategies to augment the effectiveness of the therapeutic use of postmitochondrial interventions.

scholarly journals Mitochondrial cytochrome c release is a key event in hyperoxia-induced lung injury: protection by cyclosporin A

2004 ◽  
Vol 286 (2) ◽  
pp. L275-L283 ◽  
Author(s):  
Alessandra Pagano ◽  
Yves Donati ◽  
Isabelle Métrailler ◽  
Constance Barazzone Argiroffo
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Lung Injury ◽  
Cyclosporin A ◽  
Permeability Transition ◽  
Alveolar Epithelial Cells ◽  
Alveolar Cells ◽  
Cytochrome C Release ◽  
Lung Weight ◽  
Cell Death Pathway

Hyperoxia is known to induce extensive alveolar cell death by still poorly defined mechanisms. In this study, the mitochondria-dependent cell death pathway was explored during hyperoxia-induced lung injury in mice. We observed a progressive release of cytochrome c from the mitochondria into the cytosol of alveolar cells. This release was accompanied by the translocation of the proapoptotic protein Bax from cytosol to mitochondria without detectable activation of caspase-3. As cytochrome c release can be induced by mitochondrial membrane alteration and permeability transition (MPT), mice were treated with cyclosporin A, which specifically inhibits MPT. Cyclosporin A treatment prevented mitochondrial release of cytochrome c during hyperoxia and concomitantly preserved mitochondria from extensive swelling and crista disorganization, as assessed by electron microscopy analysis of alveolar epithelial cells. These morphological and biochemical observations correlated with decreased lung tissue damage, as evaluated by morphological score and lung weight. In conclusion, mitochondrial damage and cytochrome c release are important linked events in hyperoxia-induced lung injury and can be efficiently blocked by cyclosporin A.

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