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.

Reactive oxygen species and caspase activation mediate silica-induced apoptosis in alveolar macrophages

2001 ◽  
Vol 280 (1) ◽  
pp. L10-L17 ◽  
Author(s):  
Han-Ming Shen ◽  
Zhuo Zhang ◽  
Qi-Feng Zhang ◽  
Choon-Nam Ong
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Alveolar Macrophages ◽  
Caspase 3 ◽  
Reactive Oxygen ◽  
Parp Cleavage ◽  
Oxygen Species ◽  
Caspase Activation ◽  
Caspase 9 ◽  
Induced Apoptosis

Alveolar macrophages (AMs) are the principal target cells of silica and occupy a key position in the pathogenesis of silica-related diseases. Silica has been found to induce apoptosis in AMs, whereas its underlying mechanisms involving the initiation and execution of apoptosis are largely unknown. The main objective of the present study was to examine the form of cell death caused by silica and the mechanisms involved. Silica-induced apoptosis in AMs was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay and cell cycle/DNA content analysis. The elevated level of reactive oxygen species (ROS), caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) cleavage in silica-treated AMs were also determined. The results showed that there was a temporal pattern of apoptotic events in silica-treated AMs, starting with ROS formation and followed by caspase-9 and caspase-3 activation, PARP cleavage, and DNA fragmentation. Silica-induced apoptosis was significantly attenuated by a caspase-3 inhibitor, N-acetyl-Asp-Glu-Val-Asp aldehyde, and ebselen, a potent antioxidant. These findings suggest that apoptosis is an important form of cell death caused by silica exposure in which the elevated ROS level that results from silica exposure may act as an initiator, leading to caspase activation and PARP cleavage to execute the apoptotic process.

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 Increased Oxidative Stress Induced by Rubus Bioactive Compounds Induce Apoptotic Cell Death in Human Breast Cancer Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Blassan P. George ◽  
Heidi Abrahamse
Keyword(s):  
Breast Cancer ◽  
Oxidative Stress ◽  
Cell Death ◽  
Cytochrome C ◽  
Cancer Cells ◽  
Bioactive Compounds ◽  
Breast Cancer Cells ◽  
Apoptotic Cell ◽  
Ros Production ◽  
Caspase 9

Bioactive compounds from plants represent good candidate drugs for the prevention and treatment of various forms of cancer. Berries are rich sources of bioactive compounds, and there has been an increasing interest in the study of therapeutic action of wild berries. Oxidants are generated continuously in biological system as a result of physiological process. When there is an imbalance between oxidants and antioxidants, it leads to a condition called oxidative stress. Natural compounds as inducers of oxidative stress are able to modulate the physiological functions of cancer cells leading to cell death or survival. The aim of this study was to evaluate the induction of apoptosis by isolated bioactive compounds (1-(2-hydroxyphenyl)-4-methylpentan-1-one (C1) and 2-[(3-methylbutoxy) carbonyl] benzoic acid (C2)) from Rubus fairholmianus against MCF-7 breast cancer cells. The exposure of C1 and C2 reduced viability (IC50 of C1: 4.69; C2: 8.36 μg/mL) and proliferation. Cytochrome c release from mitochondria and changes in mitochondrial membrane potential of treated cells supported the intrinsic apoptotic cell death. Reactive oxygen species (ROS) production after treatment with C1 and C2 was found to be higher and induced nuclear damage. Expression of apoptotic proteins after the treatments was significantly upregulated as indicated using immunofluorescence (caspase 9, p53, and Bax), western blotting (p53, cleaved PARP, cytochrome c, and Bax), and ELISA (caspase 9) analysis. Overall, C1 was more cytotoxic, increased the ROS production in dichlorodihydrofluorescein diacetate assay, and induced apoptosis in breast cancer cells. These results illustrate that berry bioactive compounds have strong chemopreventive potential. In this article, we provide information on prooxidant and anticancer activities of Rubus bioactive compounds. Natural products have always demonstrated a significant contribution to the development of several cancer chemotherapeutic drugs. Most of these compounds are known to affect the redox state of the cell; and studies on these compounds have focused on their antioxidant property instead of prooxidant properties.

scholarly journals The Role of Mitochondria in Pyroptosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Qian Li ◽  
Nengxian Shi ◽  
Chen Cai ◽  
Mingming Zhang ◽  
Jing He ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Pathological Process ◽  
Mitochondrial Outer Membrane ◽  
Therapeutic Effects ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Regulated Cell Death ◽  
Clinical Benefits ◽  
Regulate Cell Death

Pyroptosis is a recently discovered aspartic aspart-specific cysteine protease (Caspase-1/4/5/11) dependent mode of gene-regulated cell death cell death, which is represented by the rupture of cell membrane perforations and the production of proinflammatory mediaters like interleukin-18(IL-18) and interleukin-1β (IL-1β). Mitochondria also play an important role in apoptotic cell death. When it comes to apoptosis of mitochondrion, mitochondrial outer membrane permeabilization (MOMP) is commonly known to cause cell death. As a downstream pathological process of apoptotic signaling, MOMP participates in the leakage of cytochrome-c from mitochondrion to the cytosol and subsequently activate caspase proteases. Hence, targeting MOMP for the sake of manipulating cell death presents potential therapeutic effects among various types of diseases, such as autoimmune disorders, neurodegenerative diseases, and cancer. In this review, we highlights the roles and significance of mitochondria in pyroptosis to provide unexplored strategies that target the mitochondria to regulate cell death for clinical benefits.

scholarly journals The Effects of a Mitochondrial Targeted Peptide (Elamipretide/SS31) on BAX Recruitment and Activation During Apoptosis

2021 ◽  
Author(s):  
Joshua Grosser ◽  
Rachel Fehrman ◽  
Dennis Keefe ◽  
Martin Redmon ◽  
Robert Nickells
Keyword(s):  
Cytochrome C ◽  
Mitochondrial Outer Membrane ◽  
Intrinsic Apoptosis ◽  
Mitochondrial Fragmentation ◽  
Cytochrome C Release ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Bax Protein ◽  
Induced Apoptosis ◽  
Kinetics Of ◽  
Peptide Treatment

Abstract Objective: Elamipretide (SS31) is a mitochondria-targeted peptide that has reported functions of stabilizing mitochondrial cristae structure and improving mitochondrial bioenergetics. Several studies have documented cell protective features of this peptide, including impairment of intrinsic apoptosis by inhibiting the recruitment and activation of the pro-apoptotic BAX protein. We used live-cell imaging of ARPE-19 cells expressing fluorescently labeled BAX, cytochrome c, and a mitochondrial marker to investigate the effect of elamipretide on the kinetics of BAX recruitment, mitochondrial outer membrane permeabilization (as a function of cytochrome c release), and mitochondrial fragmentation, respectively. Result: In nucleofected and plated ARPE-19 cells, elamipretide accelerated the formation of larger mitochondria. In the presence of the apoptotic stimulator, staurosporine, cells treated with elamipretide exhibited moderately slower rates of BAX recruitment. Peptide treatment, however, did not significantly delay the onset of BAX recruitment or the final total amount of BAX that was recruited. Additionally, elamipretide showed no impairment or delay of cytochrome c release or mitochondrial fragmentation, two events associated with normal BAX activation during cell death. These results indicate that the protective effect of elamipretide is not at the level of BAX activity to induce pro-apoptotic mitochondrial dysfunction after the initiation of staurosporine-induced apoptosis.

scholarly journals Loss of Caspase-9 Reveals Its Essential Role for Caspase-2 Activation and Mitochondrial Membrane Depolarization

2007 ◽  
Vol 18 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Ajoy K. Samraj ◽  
Dennis Sohn ◽  
Klaus Schulze-Osthoff ◽  
Ingo Schmitz
Keyword(s):  
Cytochrome C ◽  
Anticancer Drugs ◽  
Mitochondrial Membrane ◽  
Genotoxic Stress ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Mitochondrial Outer Membrane Permeabilization ◽  
Mitochondrial Membrane Depolarization ◽  
Caspase 2 ◽  
Induced Apoptosis

Caspase-9 plays an important role in apoptosis induced by genotoxic stress. Irradiation and anticancer drugs trigger mitochondrial outer membrane permeabilization, resulting in cytochrome c release and caspase-9 activation. Two highly contentious issues, however, remain: It is unclear whether the loss of the mitochondrial membrane potential ΔΨMcontributes to cytochrome c release and whether caspases are involved. Moreover, an unresolved question is whether caspase-2 functions as an initiator in genotoxic stress-induced apoptosis. In the present study, we have identified a mutant Jurkat T-cell line that is deficient in caspase-9 and resistant to apoptosis. Anticancer drugs, however, could activate proapoptotic Bcl-2 proteins and cytochrome c release, similarly as in caspase-9–proficient cells. Interestingly, despite these alterations, the cells retained ΔΨM. Furthermore, processing and enzyme activity of caspase-2 were not observed in the absence of caspase-9. Reconstitution of caspase-9 expression restored not only apoptosis but also the loss of ΔΨMand caspase-2 activity. Thus, we provide genetic evidence that caspase-9 is indispensable for drug-induced apoptosis in cancer cells. Moreover, loss of ΔΨMcan be functionally separated from cytochrome c release. Caspase-9 is not only required for ΔΨMloss but also for caspase-2 activation, suggesting that these two events are downstream of the apoptosome.

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.

scholarly journals Bcr-Abl-Mediated Protection from Apoptosis Downstream of Mitochondrial Cytochrome c Release

2004 ◽  
Vol 24 (23) ◽  
pp. 10289-10299 ◽  
Author(s):  
Paula B. Deming ◽  
Zachary T. Schafer ◽  
Jessica S. Tashker ◽  
Malia B. Potts ◽  
Mohanish Deshmukh ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Mitochondrial Cytochrome ◽  
Caspase Activation ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Intact Cells ◽  
Caspase Recruitment Domain ◽  
Distinct Mechanism ◽  
Mitochondrial Cytochrome C

ABSTRACT Bcr-Abl, activated in chronic myelogenous leukemias, is a potent cell death inhibitor. Previous reports have shown that Bcr-Abl prevents apoptosis through inhibition of mitochondrial cytochrome c release. We report here that Bcr-Abl also inhibits caspase activation after the release of cytochrome c. Bcr-Abl inhibited caspase activation by cytochrome c added to cell-free lysates and prevented apoptosis when cytochrome c was microinjected into intact cells. Bcr-Abl acted posttranslationally to prevent the cytochrome c-induced binding of Apaf-1 to procaspase 9. Although Bcr-Abl prevented interaction of endogenous Apaf-1 with the recombinant prodomain of caspase 9, it did not affect the association of endogenous caspase 9 with the isolated Apaf-1 caspase recruitment domain (CARD) or Apaf-1 lacking WD-40 repeats. These data suggest that Apaf-1 recruitment of caspase 9 is faulty in the presence of Bcr-Abl and that cytochrome c/dATP-induced exposure of the Apaf-1 CARD is likely defective. These data provide a novel locus of Bcr-Abl antiapoptotic action and suggest a distinct mechanism of apoptosomal inhibition.

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.

Sign in / Sign up

Export Citation Format

Share Document