scholarly journals Dual Signaling of the Fas Receptor: Initiation of Both Apoptotic and Necrotic Cell Death Pathways

1998 ◽  
Vol 188 (5) ◽  
pp. 919-930 ◽  
Author(s):  
Dominique Vercammen ◽  
Greet Brouckaert ◽  
Geertrui Denecker ◽  
Marc Van de Craen ◽  
Wim Declercq ◽  
...  
Keyword(s):  
Cell Death ◽  
Nuclear Factor Κb ◽  
Oxygen Radical ◽  
Radical Scavenger ◽  
Apoptotic Pathway ◽  
Proteolytic Activation ◽  
Fas Receptor ◽  
Caspase Inhibitors ◽  
Cell Death Pathways ◽  
Induced Apoptosis

Murine L929 fibrosarcoma cells were transfected with the human Fas (APO-1/CD95) receptor, and the role of various caspases in Fas-mediated cell death was assessed. Proteolytic activation of procaspase-3 and -7 was shown by Western analysis. Acetyl-Tyr-Val-Ala-Asp-chloromethylketone and benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethylketone, tetrapeptide inhibitors of caspase-1– and caspase-3–like proteases, respectively, failed to block Fas-induced apoptosis. Unexpectedly, the broad-spectrum caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone and benzyloxycarbonyl-Asp(OMe)-fluoromethylketone rendered the cells even more sensitive to Fas-mediated cell death, as measured after 18 h incubation. However, when the process was followed microscopically, it became clear that anti-Fas–induced apoptosis of Fas-transfected L929 cells was blocked during the first 3 h, and subsequently the cells died by necrosis. As in tumor necrosis factor (TNF)-induced necrosis, Fas treatment led to accumulation of reactive oxygen radicals, and Fas-mediated necrosis was inhibited by the oxygen radical scavenger butylated hydroxyanisole. However, in contrast to TNF, anti-Fas did not activate the nuclear factor κB under these necrotic conditions. These results demonstrate the existence of two different pathways originating from the Fas receptor, one rapidly leading to apoptosis, and, if this apoptotic pathway is blocked by caspase inhibitors, a second directing the cells to necrosis and involving oxygen radical production.

A20 protects endothelial cells from TNF-, Fas-, and NK-mediated cell death by inhibiting caspase 8 activation

Blood ◽  
2004 ◽  
Vol 104 (8) ◽  
pp. 2376-2384 ◽  
Author(s):  
Soizic Daniel ◽  
Maria B. Arvelo ◽  
Virendra I. Patel ◽  
Christopher R. Longo ◽  
Gautam Shrikhande ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Killer Cell ◽  
Nuclear Factor Κb ◽  
Caspase 8 ◽  
Apoptotic Pathway ◽  
Cell Death Pathways ◽  
Executioner Caspases ◽  
First Time ◽  
Necrosis Factor

Abstract A20 is a stress response gene in endothelial cells (ECs). A20 serves a dual cytoprotective function, protecting from tumor necrosis factor (TNF)–mediated apoptosis and inhibiting inflammation via blockade of the transcription factor nuclear factor–κB (NF-κB). In this study, we evaluated the molecular basis of the cytoprotective function of A20 in EC cultures and questioned whether its protective effect extends beyond TNF to other apoptotic and necrotic stimuli. Our data demonstrate that A20 targets the TNF apoptotic pathway by inhibiting proteolytic cleavage of apical caspases 8 and 2, executioner caspases 3 and 6, Bid cleavage, and release of cytochrome c, thus preserving mitochondrion integrity. A20 also protects from Fas/CD95 and significantly blunts natural killer cell–mediated EC apoptosis by inhibiting caspase 8 activation. In addition to protecting ECs from apoptotic stimuli, A20 safeguards ECs from complement-mediated necrosis. These data demonstrate, for the first time, that the cytoprotective effect of A20 in ECs is not limited to TNF-triggered apoptosis. Rather, A20 affords broad EC protective functions by effectively shutting down cell death pathways initiated by inflammatory and immune offenders.

scholarly journals FKBP51 Affects TNF-Related Apoptosis Inducing Ligand Response in Melanoma

2021 ◽  
Vol 9 ◽  
Author(s):  
Martina Tufano ◽  
Elena Cesaro ◽  
Rosanna Martinelli ◽  
Roberto Pacelli ◽  
Simona Romano ◽  
...  
Keyword(s):  
Cell Death ◽  
Immune Cells ◽  
Histone Deacetylases ◽  
Melanoma Cells ◽  
Transcriptional Level ◽  
Cell Death Pathways ◽  
Yin Yang 1 ◽  
Immune Precipitation ◽  
Induced Apoptosis ◽  
Repressor Activity

Melanoma is one of the most immunogenic tumors and has the highest potential to elicit specific adaptive antitumor immune responses. Immune cells induce apoptosis of cancer cells either by soluble factors or by triggering cell-death pathways. Melanoma cells exploit multiple mechanisms to escape immune system tumoricidal control. FKBP51 is a relevant pro-oncogenic factor of melanoma cells supporting NF-κB-mediated resistance and cancer stemness/invasion epigenetic programs. Herein, we show that FKBP51-silencing increases TNF-related apoptosis-inducing ligand (TRAIL)-R2 (DR5) expression and sensitizes melanoma cells to TRAIL-induced apoptosis. Consistent with the general increase in histone deacetylases, as by the proteomic profile, the immune precipitation assay showed decreased acetyl-Yin Yang 1 (YY1) after FKBP51 depletion, suggesting an impaired repressor activity of this transcription factor. ChIP assay supported this hypothesis. Compared with non-silenced cells, a reduced acetyl-YY1 was found on the DR5 promoter, resulting in increased DR5 transcript levels. Using Crispr/Cas9 knockout (KO) melanoma cells, we confirmed the negative regulation of DR5 by FKBP51. We also show that KO cells displayed reduced levels of acetyl-EP300 responsible for YY1 acetylation, along with reduced acetyl-YY1. Reconstituting FKBP51 levels contrasted the effects of KO on DR5, acetyl-YY1, and acetyl-EP300 levels. In conclusion, our finding shows that FKBP51 reduces DR5 expression at the transcriptional level by promoting YY1 repressor activity. Our study supports the conclusion that targeting FKBP51 increases the expression level of DR5 and sensitivity to TRAIL-induced cell death, which can improve the tumoricidal action of immune cells.

scholarly journals A Novel High-Throughput Technique for Identifying Monoclonal Antibodies capable of Death Receptor Induced Apoptosis

2009 ◽  
Vol 2 ◽  
pp. JCD.S3660
Author(s):  
Hang Fai Kwok ◽  
Julie A. Gormley ◽  
Christopher J. Scott ◽  
James A. Johnston ◽  
Shane A. Olwill
Keyword(s):  
Cell Death ◽  
High Throughput ◽  
High Throughput Screening ◽  
False Negative ◽  
Death Receptor ◽  
Annexin V ◽  
Fas Receptor ◽  
Induced Apoptosis

The study of death receptor family induced apoptosis has gained momentum in recent years with the knowledge that therapeutic antibodies targeting DR4 and DR5 (death receptor's 4 and 5) have proved efficacious in multiple clinical trials. The therapeutic rationale is based on targeting and amplifying a tumour tissues normal cell death programme (apoptosis). While advances in the targeting of DR4 and DR5 have been successful the search for an agonistic antibody to another family member, the Fas receptor, has proven more elusive. This is partly due to the differing in vitro and in vivo characteristics of individual antibodies. In order to induce Fas targeted cell death an antibody must be capable of binding to and trimerising the receptor. It has been shown that antibodies capable of performing this function in vivo, with the assistance of tumour associated cells, do not always induce apoptosis in vitro. As a result the use of current methodologies to detect functional antibodies in vitro may have dismissed potential therapeutic candidates ('false negative'). Here we report a novel high throughput screening technique which artificially cross-links antibodies bound to the Fas receptor. By combining this process with Annexin-V and Prodidium Iodide (PI) staining we can select for antibodies which have the potential to induce apoptosis in vivo.

Role of NF-κB in β-cell death

2008 ◽  
Vol 36 (3) ◽  
pp. 334-339 ◽  
Author(s):  
Danielle Melloul
Keyword(s):  
Cell Death ◽  
Lymphocytic Infiltration ◽  
Nuclear Factor Κb ◽  
Interferon Γ ◽  
Cell Protection ◽  
Β Cells ◽  
Β Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Apoptotic β-cell death appears to be central to the pathogenesis of Type 1 diabetes mellitus and in islet graft rejection. The β-cell destruction is partially mediated by cytokines, such as IL-1β (interleukin 1β), TNFα (tumour necrosis factor α) and IFN-γ (interferon γ). IL-1β and TNFα mediate activation of the transcription factor NF-κB (nuclear factor κB) pathway. Use of a degradation-resistant NF-κB protein inhibitor (ΔNIκBα), specifically expressed in β-cells, significantly reduced IL-1β+IFN-γ-induced apoptosis. Moreover, in vivo, it protected against multiple low-dose streptozocin-induced diabetes, with reduced intra-islet lymphocytic infiltration. Thus β-cell-specific activation of NF-κB is a key event in the progressive loss of β-cells in diabetes. Inhibition of this process could be a potential effective strategy for β-cell protection.

Caspase-dependent and -independent pathways for cadmium-induced apoptosis in cultured kidney proximal tubule cells

2006 ◽  
Vol 291 (4) ◽  
pp. F823-F832 ◽  
Author(s):  
Wing-Kee Lee ◽  
Marouan Abouhamed ◽  
Frank Thévenod
Keyword(s):  
Cell Death ◽  
Proximal Tubule ◽  
Rat Kidney ◽  
Cadmium Concentration ◽  
Nuclear Staining ◽  
Kidney Proximal Tubule ◽  
Cell Death Pathways ◽  
Cyt C ◽  
Induced Apoptosis ◽  
Apoptosis Inducing Factor

The nephrotoxic metal cadmium at micromolar concentrations induces apoptosis of rat kidney proximal tubule (PT) cells within 3–6 h of exposure. The underlying cell death pathways remain poorly defined. Using Hoechst 33342/ethidium bromide nuclear staining and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cell death assays, 10–50 μM cadmium induced apoptosis of immortalized rat kidney cells derived from the S1-segment of PT at 6 and 24 h, but necrosis at 24 h only. Cadmium (10–50 μM) also caused mitochondrial cytochrome c (cyt. c)- and apoptosis-inducing factor release at 24 h, but not at 6 h, as measured by immunofluorescence imaging and immunoblotting. Caspases-9 and -3 were activated only by 10 μM cadmium for 24 h, and accordingly apoptosis was significantly reduced by the respective inhibitors (z-LEHD-fmk, z-DEVD-fmk; 10 μg/ml) at 24 h, but not at 6 h, without affecting necrosis. At 6 h, 10 μM cadmium increased the activity of the calcium-activated protease calpain, but not at 24 h, and calpain inhibitors (ALLN, PD 150606; 10–30 μM) blocked apoptosis by 10 μM cadmium at 3–6 h. However, PD-150606 also attenuated caspase-3 activity and apoptosis at 24 h, suggesting calpain-dependent caspase activation. Thus cadmium-induced apoptosis of PT cells involves a complex and sensitive interplay of signaling cascades involving mitochondrial proapoptotic factors, calpains and caspases, whose activation is also determined by cadmium concentration and the duration of cadmium exposure.

scholarly journals TWEAKing death

2008 ◽  
Vol 182 (1) ◽  
pp. 15-17 ◽  
Author(s):  
Jonathan D. Ashwell
Keyword(s):  
Cell Death ◽  
Cell Biology ◽  
Nuclear Factor Κb ◽  
Tnf Receptor ◽  
Tumor Cell Death ◽  
Cell Death Pathways ◽  
Tnf Α ◽  
Selective Elimination ◽  
Smac Mimetics ◽  
Necrosis Factor

Smac mimetics (inhibitor of apoptosis [IAP] antagonists) are synthetic reagents that kill susceptible tumor cells by inducing degradation of cellular IAP (cIAP) 1 and cIAP2, nuclear factor κB activation, tumor necrosis factor (TNF) α production, TNF receptor 1 occupancy, and caspase-8 activation. In this issue of The Journal of Cell Biology, Vince et al. (see p. 171) report remarkable similarities in the events leading to tumor cell death triggered by the cytokine TWEAK (TNF-like weak inducer of apoptosis) and IAP antagonists. Although the mechanistic details differ, a common and necessary feature that is also shared by TNF receptor 2 signaling is reduction in the level of cIAP1 and, in some cases, cIAP2 and TNF receptor-associated factor 2. These findings not only extend our appreciation of how cell death pathways are kept in check in tumors, they reinforce the possible utility of induced cIDE (cIAP deficiency) in the selective elimination of neoplastic cells.

A Novel Ring-Substituted Diindolylmethane 1,1-bis [3′-(5-methoxyindolyl)]-1-(p-t-butylphenyl) Methane Abrogates ERK Activation and Induces Apoptosis in Acute Myeloid Leukemia (AML).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3399-3399
Author(s):  
Rooha Contractor ◽  
Ismael J. Samudio ◽  
Zeev Estrov ◽  
David Harris ◽  
James A. McCubrey ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Caspase 9 ◽  
Apoptotic Pathway ◽  
Erk Activation ◽  
New Class ◽  
Induced Apoptosis ◽  
Extracellular Regulated Kinase

Abstract We investigated the antileukemic activity and molecular mechanisms of action of a newly synthesized ring-substituted diindolylmethane (DIM) derivative, named, 1,1-bis [3′-(5-methoxyindolyl)]-1-(p-t-butylphenyl) methane (DIM #34), in myeloid leukemic cells. DIM #34 inhibited leukemic cell growth via induction of apoptosis. DIM #34 inhibited clonogenic growth and induced apoptosis of AML CD34+ progenitor cells but spared normal progenitors. DIM #34 induced loss of mitochondrial membrane potential, which was accompanied by the release of cytochrome c into the cytosol and early cleavage of caspase-9 followed by the cleavage of caspases -8, and -3. Bcl-2 overexpression and caspase-9-deficient cells were partially protected against DIM #34-induced apoptosis, suggesting activation of the intrinsic apoptotic pathway. DIM #34 induced Bax cleavage, and Bax knockout cells were partially resistant to cell death. Furthermore, DIM #34 transiently inhibited the phosphorylation and the activity of the extracellular-regulated kinase (ERK) and abrogated Bcl-2 phosphorylation. Because other methylene substituted DIM analogs transactivate the nuclear receptor PPARγ, we studied the role of PPARγ in apoptosis induction. Although the co-treatment of cells with a selective PPARγ antagonist T007, and a low dose of DIM #34 partially diminished apoptosis, apoptosis was not inhibited at higher concentrations of DIM #34, suggesting the involvement of both, receptor-dependent and independent mechanisms. Co-treatment with RXR- and RAR-ligands enhanced DIM #34-induced cell death. Together, these findings showed that substituted DIMs represent a new class of compounds that selectively induce apoptosis in AML cells through interference with ERK and activation of PPARγ signaling pathways.

scholarly journals Varicella-Zoster Virus ORF63 Protects Human Neuronal and Keratinocyte Cell Lines from Apoptosis and Changes Its Localization upon Apoptosis Induction

2018 ◽  
Vol 92 (12) ◽  
pp. e00338-18 ◽  
Author(s):  
Chelsea Gerada ◽  
Megan Steain ◽  
Brian P. McSharry ◽  
Barry Slobedman ◽  
Allison Abendroth
Keyword(s):  
Cell Death ◽  
Varicella Zoster Virus ◽  
Gene Product ◽  
Postherpetic Neuralgia ◽  
Hacat Cells ◽  
Apoptosis Induction ◽  
Varicella Zoster ◽  
Cell Death Pathways ◽  
Keratinocyte Cell ◽  
Induced Apoptosis

ABSTRACTThere are many facets of varicella-zoster virus (VZV) pathogenesis that are not fully understood, such as the mechanisms involved in the establishment of lifelong latency, reactivation, and development of serious conditions like postherpetic neuralgia (PHN). Virus-encoded modulation of apoptosis has been suggested to play an important role in these processes. VZV open reading frame 63 (ORF63) has been shown to modulate apoptosis in a cell-type-specific manner, but the impact of ORF63 on cell death pathways has not been examined in isolation in the context of human cells. We sought to elucidate the effect of VZV ORF63 on apoptosis induction in human neuron and keratinocyte cell lines. VZV ORF63 was shown to protect differentiated SH-SY5Y neuronal cells against staurosporine-induced apoptosis. In addition, VZV infection did not induce high levels of apoptosis in the HaCaT human keratinocyte line, highlighting a delay in apoptosis induction. VZV ORF63 was shown to protect HaCaT cells against both staurosporine- and Fas ligand-induced apoptosis. Confocal microscopy was utilized to examine VZV ORF63 localization during apoptosis induction. In VZV infection and ORF63 expression alone, VZV ORF63 became more cytoplasmic, with aggregate formation during apoptosis induction. Taken together, this suggests that VZV ORF63 protects both differentiated SH-SY5Y cells and HaCaT cells from apoptosis induction and may mediate this effect through its localization change during apoptosis. VZV ORF63 is a prominent VZV gene product in both productive and latent infection and thus may play a critical role in VZV pathogenesis by aiding neuron and keratinocyte survival.IMPORTANCEVZV, a human-specific alphaherpesvirus, causes chicken pox during primary infection and establishes lifelong latency in the dorsal root ganglia (DRG). Reactivation of VZV causes shingles, which is often followed by a prolonged pain syndrome called postherpetic neuralgia. It has been suggested that the ability of the virus to modulate cell death pathways is linked to its ability to establish latency and reactivate. The significance of our research lies in investigating the ability of ORF63, a VZV gene product, to inhibit apoptosis in novel cell types crucial for VZV pathogenesis. This will allow an increased understanding of critical enigmatic components of VZV pathogenesis.

scholarly journals Evidence for Agrobacterium-Induced Apoptosis in Maize Cells

2000 ◽  
Vol 13 (6) ◽  
pp. 649-657 ◽  
Author(s):  
Geneviève Hansen
Keyword(s):  
Cell Death ◽  
Dna Cleavage ◽  
Morphological Changes ◽  
Plant Cells ◽  
Plant Tissues ◽  
Apoptotic Pathway ◽  
Dicotyledonous Plant ◽  
Apoptotic Genes ◽  
Baculovirus P35 ◽  
Induced Apoptosis

Agrobacterium spp. can genetically transform most dicotyledonous plant cells whereas many monocot species are recalcitrant to Agrobacterium-mediated transformation. One major obstacle is that co-cultivation of Agrobacterium spp. with plant tissues often results in cell death. Report here is that, in maize tissues, this process resembles apoptosis, with characteristic DNA cleavage into oligonucleosomal fragments and morphological changes. Two anti-apoptotic genes from baculovirus, p35 and iap, had the ability to prevent the onset of apoptosis triggered by Agrobacterium spp. in maize tissues. p35 is reported to act as a direct inhibitor of a certain class of proteases (caspase) whereas iap may act upstream to prevent their activation. This evidence raises the possibility that caspase-like proteases may also be involved in the apoptotic pathway in plant cells.

scholarly journals Downregulation of PUMA underlies resistance to FGFR1 inhibitors in the stem cell leukemia/lymphoma syndrome

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Yun Liu ◽  
Baohuan Cai ◽  
Yating Chong ◽  
Hualei Zhang ◽  
Chesley-Anne Kemp ◽  
...  
Keyword(s):  
Cell Death ◽  
Kinase Inhibitors ◽  
Leukemic Cells ◽  
Direct Role ◽  
Genetic Changes ◽  
Cell Death Pathways ◽  
Pten Deletion ◽  
Induced Apoptosis ◽  
Resistant Cells

Abstract Resistance to molecular therapies frequently occur due to genetic changes affecting the targeted pathway. In myeloid and lymphoid leukemias/lymphomas resulting from constitutive activation of FGFR1 kinases, resistance has been shown to be due either to mutations in FGFR1 or deletions of PTEN. RNA-Seq analysis of the resistant clones demonstrates expression changes in cell death pathways centering on the p53 upregulated modulator of apoptosis (Puma) protein. Treatment with different tyrosine kinase inhibitors (TKIs) revealed that, in both FGFR1 mutation and Pten deletion-mediated resistance, sustained Akt activation in resistant cells leads to compromised Puma activation, resulting in suppression of TKI-induced apoptosis. This suppression of Puma is achieved as a result of sequestration of inactivated p-Foxo3a in the cytoplasm. CRISPR/Cas9 mediated knockout of Puma in leukemic cells led to an increased drug resistance in the knockout cells demonstrating a direct role in TKI resistance. Since Puma promotes cell death by targeting Bcl2, TKI-resistant cells showed high Bcl2 levels and targeting Bcl2 with Venetoclax (ABT199) led to increased apoptosis in these cells. In vivo treatment of mice xenografted with resistant cells using ABT199 suppressed leukemogenesis and led to prolonged survival. This in-depth survey of the underlying genetic mechanisms of resistance has identified a potential means of treating FGFR1-driven malignancies that are resistant to FGFR1 inhibitors.

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